Return to ChangeLog CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / pcre

8.33

    1: ChangeLog for PCRE
    2: ------------------
    3: 
    4: Version 8.33 28-May-2013
    5: --------------------------
    6: 
    7: 1.  Added 'U' to some constants that are compared to unsigned integers, to
    8:     avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
    9:     variables that are added to signed variables, to ensure the result is
   10:     signed and can be negated.
   11: 
   12: 2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
   13:     CMake config files.
   14: 
   15: 3.  Revise the creation of config.h.generic so that all boolean macros are
   16:     #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
   17:     overriding via -D on the command line possible.
   18: 
   19: 4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
   20:     to unsigned int is reported to make a quite noticeable speed difference in
   21:     a specific Windows environment. Testing on Linux did also appear to show
   22:     some benefit (and it is clearly not harmful). Also fixed the definition of
   23:     Xop which should be unsigned.
   24: 
   25: 5.  Related to (4), changing the definition of the intermediate variable cc
   26:     in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
   27:     improvements.
   28: 
   29: 6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
   30:     unnecessary spaces.
   31: 
   32: 7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
   33:     and later.
   34: 
   35: 8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
   36: 
   37: 9.  Optimizing fast_forward_start_bits in JIT.
   38: 
   39: 10. Adding support for callouts in JIT, and fixing some issues revealed
   40:     during this work. Namely:
   41: 
   42:     (a) Unoptimized capturing brackets incorrectly reset on backtrack.
   43: 
   44:     (b) Minimum length was not checked before the matching is started.
   45: 
   46: 11. The value of capture_last that is passed to callouts was incorrect in some
   47:     cases when there was a capture on one path that was subsequently abandoned
   48:     after a backtrack. Also, the capture_last value is now reset after a
   49:     recursion, since all captures are also reset in this case.
   50: 
   51: 12. The interpreter no longer returns the "too many substrings" error in the
   52:     case when an overflowing capture is in a branch that is subsequently
   53:     abandoned after a backtrack.
   54: 
   55: 13. In the pathological case when an offset vector of size 2 is used, pcretest
   56:     now prints out the matched string after a yield of 0 or 1.
   57: 
   58: 14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
   59:     Only supported by the JIT compiler at the moment.
   60: 
   61: 15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
   62: 
   63: 16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
   64:     offset of the starting point of the matching process, provided the offsets
   65:     vector is large enough.
   66: 
   67: 17. The \A escape now records a lookbehind value of 1, though its execution
   68:     does not actually inspect the previous character. This is to ensure that,
   69:     in partial multi-segment matching, at least one character from the old
   70:     segment is retained when a new segment is processed. Otherwise, if there
   71:     are no lookbehinds in the pattern, \A might match incorrectly at the start
   72:     of a new segment.
   73: 
   74: 18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
   75: 
   76: 19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
   77:     gives some modest performance improvement in 8-bit mode.
   78: 
   79: 20. Added the PCRE-specific property \p{Xuc} for matching characters that can
   80:     be expressed in certain programming languages using Universal Character
   81:     Names.
   82: 
   83: 21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
   84:     which points out that "non characters" are not "characters that may not
   85:     appear in Unicode strings" but rather "characters that are reserved for
   86:     internal use and have only local meaning".
   87: 
   88: 22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
   89:     there was a conditional group that depended on an assertion, if the
   90:     assertion was false, the callout that immediately followed the alternation
   91:     in the condition was skipped when pcre_exec() was used for matching.
   92: 
   93: 23. Allow an explicit callout to be inserted before an assertion that is the
   94:     condition for a conditional group, for compatibility with automatic
   95:     callouts, which always insert a callout at this point.
   96: 
   97: 24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
   98:     confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
   99: 
  100: 25. (*PRUNE) is now supported by the JIT compiler.
  101: 
  102: 26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
  103: 
  104: 27. Fix the case where there are two or more SKIPs with arguments that may be
  105:     ignored.
  106: 
  107: 28. (*SKIP) is now supported by the JIT compiler.
  108: 
  109: 29. (*THEN) is now supported by the JIT compiler.
  110: 
  111: 30. Update RunTest with additional test selector options.
  112: 
  113: 31. The way PCRE handles backtracking verbs has been changed in two ways.
  114: 
  115:     (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
  116:     SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
  117:     backtracking. In some cases this makes it more Perl-compatible, but Perl's
  118:     rather obscure rules do not always do the same thing.
  119: 
  120:     (2) Previously, backtracking verbs were confined within assertions. This is
  121:     no longer the case for positive assertions, except for (*ACCEPT). Again,
  122:     this sometimes improves Perl compatibility, and sometimes does not.
  123: 
  124: 32. A number of tests that were in test 2 because Perl did things differently
  125:     have been moved to test 1, because either Perl or PCRE has changed, and
  126:     these tests are now compatible.
  127: 
  128: 32. Backtracking control verbs are now handled in the same way in JIT and
  129:     interpreter.
  130: 
  131: 33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
  132:     contained a forward subroutine reference caused a compile error.
  133: 
  134: 34. Auto-detect and optimize limited repetitions in JIT.
  135: 
  136: 35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
  137:     blocking (*UTF) etc.
  138: 
  139: 36. In the interpreter, maximizing pattern repetitions for characters and
  140:     character types now use tail recursion, which reduces stack usage.
  141: 
  142: 37. The value of the max lookbehind was not correctly preserved if a compiled
  143:     and saved regex was reloaded on a host of different endianness.
  144: 
  145: 38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
  146:     of the compiled pattern block, expand the flags field from 16 to 32 bits
  147:     because it was almost full.
  148: 
  149: 39. Try madvise first before posix_madvise.
  150: 
  151: 40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
  152:     with a pattern such as ^$. It has taken 4 years for anybody to notice! The
  153:     original change locked out all matches of empty strings. This has been
  154:     changed so that one match of an empty string per line is recognized.
  155:     Subsequent searches on the same line (for colouring or for --only-matching,
  156:     for example) do not recognize empty strings.
  157: 
  158: 41. Applied a user patch to fix a number of spelling mistakes in comments.
  159: 
  160: 42. Data lines longer than 65536 caused pcretest to crash.
  161: 
  162: 43. Clarified the data type for length and startoffset arguments for pcre_exec
  163:     and pcre_dfa_exec in the function-specific man pages, where they were
  164:     explicitly stated to be in bytes, never having been updated. I also added
  165:     some clarification to the pcreapi man page.
  166: 
  167: 44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
  168:     a segmentation fault.
  169: 
  170: 
  171: Version 8.32 30-November-2012
  172: -----------------------------
  173: 
  174: 1.  Improved JIT compiler optimizations for first character search and single
  175:     character iterators.
  176: 
  177: 2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
  178:     Patch by Daniel Richard G.
  179: 
  180: 3.  Single character iterator optimizations in the JIT compiler.
  181: 
  182: 4.  Improved JIT compiler optimizations for character ranges.
  183: 
  184: 5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
  185:     Reported by Giuseppe D'Angelo.
  186: 
  187: 6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
  188:     of a line, was being set incorrectly in cases where .* appeared inside
  189:     atomic brackets at the start of a pattern, or where there was a subsequent
  190:     *PRUNE or *SKIP.
  191: 
  192: 7.  Improved instruction cache flush for POWER/PowerPC.
  193:     Patch by Daniel Richard G.
  194: 
  195: 8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
  196:     grep:
  197: 
  198:     (a) There is now no limit to the number of patterns to be matched.
  199: 
  200:     (b) An error is given if a pattern is too long.
  201: 
  202:     (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
  203:         are now supported.
  204: 
  205:     (d) --exclude-from and --include-from (multiple use) have been added.
  206: 
  207:     (e) Exclusions and inclusions now apply to all files and directories, not
  208:         just to those obtained from scanning a directory recursively.
  209: 
  210:     (f) Multiple uses of -f and --file-list are now supported.
  211: 
  212:     (g) In a Windows environment, the default for -d has been changed from
  213:         "read" (the GNU grep default) to "skip", because otherwise the presence
  214:         of a directory in the file list provokes an error.
  215: 
  216:     (h) The documentation has been revised and clarified in places.
  217: 
  218: 9.  Improve the matching speed of capturing brackets.
  219: 
  220: 10. Changed the meaning of \X so that it now matches a Unicode extended
  221:     grapheme cluster.
  222: 
  223: 11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
  224:     out POSIX threads when JIT support is configured.
  225: 
  226: 12. Added support for PCRE_STUDY_EXTRA_NEEDED.
  227: 
  228: 13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
  229:     structure could go wrong in environments where size_t is not the same size
  230:     as int.
  231: 
  232: 14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
  233:     set.
  234: 
  235: 15. The EBCDIC support had decayed; later updates to the code had included
  236:     explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
  237:     general tidy up of EBCDIC-related issues, and the documentation was also
  238:     not quite right. There is now a test that can be run on ASCII systems to
  239:     check some of the EBCDIC-related things (but is it not a full test).
  240: 
  241: 16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
  242:     in a small tidy to the code.
  243: 
  244: 17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
  245: 
  246: 18. If the --only-matching (-o) option in pcregrep is specified multiple
  247:     times, each one causes appropriate output. For example, -o1 -o2 outputs the
  248:     substrings matched by the 1st and 2nd capturing parentheses. A separating
  249:     string can be specified by --om-separator (default empty).
  250: 
  251: 19. Improving the first n character searches.
  252: 
  253: 20. Turn case lists for horizontal and vertical white space into macros so that
  254:     they are defined only once.
  255: 
  256: 21. This set of changes together give more compatible Unicode case-folding
  257:     behaviour for characters that have more than one other case when UCP
  258:     support is available.
  259: 
  260:     (a) The Unicode property table now has offsets into a new table of sets of
  261:         three or more characters that are case-equivalent. The MultiStage2.py
  262:         script that generates these tables (the pcre_ucd.c file) now scans
  263:         CaseFolding.txt instead of UnicodeData.txt for character case
  264:         information.
  265: 
  266:     (b) The code for adding characters or ranges of characters to a character
  267:         class has been abstracted into a generalized function that also handles
  268:         case-independence. In UTF-mode with UCP support, this uses the new data
  269:         to handle characters with more than one other case.
  270: 
  271:     (c) A bug that is fixed as a result of (b) is that codepoints less than 256
  272:         whose other case is greater than 256 are now correctly matched
  273:         caselessly. Previously, the high codepoint matched the low one, but not
  274:         vice versa.
  275: 
  276:     (d) The processing of \h, \H, \v, and \ in character classes now makes use
  277:         of the new class addition function, using character lists defined as
  278:         macros alongside the case definitions of 20 above.
  279: 
  280:     (e) Caseless back references now work with characters that have more than
  281:         one other case.
  282: 
  283:     (f) General caseless matching of characters with more than one other case
  284:         is supported.
  285: 
  286: 22. Unicode character properties were updated from Unicode 6.2.0
  287: 
  288: 23. Improved CMake support under Windows. Patch by Daniel Richard G.
  289: 
  290: 24. Add support for 32-bit character strings, and UTF-32
  291: 
  292: 25. Major JIT compiler update (code refactoring and bugfixing).
  293:     Experimental Sparc 32 support is added.
  294: 
  295: 26. Applied a modified version of Daniel Richard G's patch to create
  296:     pcre.h.generic and config.h.generic by "make" instead of in the
  297:     PrepareRelease script.
  298: 
  299: 27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
  300:     pcre_compile.c when checking for a zero character.
  301: 
  302: 28. Introducing a native interface for JIT. Through this interface, the compiled
  303:     machine code can be directly executed. The purpose of this interface is to
  304:     provide fast pattern matching, so several sanity checks are not performed.
  305:     However, feature tests are still performed. The new interface provides
  306:     1.4x speedup compared to the old one.
  307: 
  308: 29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
  309:     the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
  310:     was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
  311: 
  312: 30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
  313:     greater than 0x7fffffff (which cannot be represented in UTF-8, even under
  314:     the "old" RFC 2279). Instead, it ended up passing a negative length to
  315:     pcre_exec().
  316: 
  317: 31. Add support for GCC's visibility feature to hide internal functions.
  318: 
  319: 32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
  320:     "unknown -C option" after outputting 0 or 1.
  321: 
  322: 33. There is now support for generating a code coverage report for the test
  323:     suite in environments where gcc is the compiler and lcov is installed. This
  324:     is mainly for the benefit of the developers.
  325: 
  326: 34. If PCRE is built with --enable-valgrind, certain memory regions are marked
  327:     unaddressable using valgrind annotations, allowing valgrind to detect
  328:     invalid memory accesses. This is mainly for the benefit of the developers.
  329: 
  330: 25. (*UTF) can now be used to start a pattern in any of the three libraries.
  331: 
  332: 26. Give configure error if --enable-cpp but no C++ compiler found.
  333: 
  334: 
  335: Version 8.31 06-July-2012
  336: -------------------------
  337: 
  338: 1.  Fixing a wrong JIT test case and some compiler warnings.
  339: 
  340: 2.  Removed a bashism from the RunTest script.
  341: 
  342: 3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
  343:     to unsigned type, result still unsigned" that was given by an MS compiler
  344:     on encountering the code "-sizeof(xxx)".
  345: 
  346: 4.  Partial matching support is added to the JIT compiler.
  347: 
  348: 5.  Fixed several bugs concerned with partial matching of items that consist
  349:     of more than one character:
  350: 
  351:     (a) /^(..)\1/ did not partially match "aba" because checking references was
  352:         done on an "all or nothing" basis. This also applied to repeated
  353:         references.
  354: 
  355:     (b) \R did not give a hard partial match if \r was found at the end of the
  356:         subject.
  357: 
  358:     (c) \X did not give a hard partial match after matching one or more
  359:         characters at the end of the subject.
  360: 
  361:     (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
  362:         a partial match for the string "\r".
  363: 
  364:     (e) When newline was set to CRLF, the metacharacter "." did not recognize
  365:         a partial match for a CR character at the end of the subject string.
  366: 
  367: 6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
  368:     running pcretest, the text "(JIT)" added to the output whenever JIT is
  369:     actually used to run the match.
  370: 
  371: 7.  Individual JIT compile options can be set in pcretest by following -s+[+]
  372:     or /S+[+] with a digit between 1 and 7.
  373: 
  374: 8.  OP_NOT now supports any UTF character not just single-byte ones.
  375: 
  376: 9.  (*MARK) control verb is now supported by the JIT compiler.
  377: 
  378: 10. The command "./RunTest list" lists the available tests without actually
  379:     running any of them. (Because I keep forgetting what they all are.)
  380: 
  381: 11. Add PCRE_INFO_MAXLOOKBEHIND.
  382: 
  383: 12. Applied a (slightly modified) user-supplied patch that improves performance
  384:     when the heap is used for recursion (compiled with --disable-stack-for-
  385:     recursion). Instead of malloc and free for each heap frame each time a
  386:     logical recursion happens, frames are retained on a chain and re-used where
  387:     possible. This sometimes gives as much as 30% improvement.
  388: 
  389: 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
  390:     call.
  391: 
  392: 14. As documented, (*COMMIT) is now confined to within a positive assertion.
  393: 
  394: 15. It is now possible to link pcretest with libedit as an alternative to
  395:     libreadline.
  396: 
  397: 16. (*COMMIT) control verb is now supported by the JIT compiler.
  398: 
  399: 17. The Unicode data tables have been updated to Unicode 6.1.0.
  400: 
  401: 18. Added --file-list option to pcregrep.
  402: 
  403: 19. Added binary file support to pcregrep, including the -a, --binary-files,
  404:     -I, and --text options.
  405: 
  406: 20. The madvise function is renamed for posix_madvise for QNX compatibility
  407:     reasons. Fixed by Giuseppe D'Angelo.
  408: 
  409: 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
  410: 
  411: 22. Changed the option for creating symbolic links for 16-bit man pages from
  412:     -s to -sf so that re-installing does not cause issues.
  413: 
  414: 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
  415: 
  416: 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
  417:     matches in certain environments (the workspace was not being correctly
  418:     retained). Also added to pcre_dfa_exec() a simple plausibility check on
  419:     some of the workspace data at the beginning of a restart.
  420: 
  421: 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
  422:     was not doing so when it should - probably a typo introduced by SVN 528
  423:     (change 8.10/14).
  424: 
  425: 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
  426:     \w+ when the character tables indicated that \x{c4} was a word character.
  427:     There were several related cases, all because the tests for doing a table
  428:     lookup were testing for characters less than 127 instead of 255.
  429: 
  430: 27. If a pattern contains capturing parentheses that are not used in a match,
  431:     their slots in the ovector are set to -1. For those that are higher than
  432:     any matched groups, this happens at the end of processing. In the case when
  433:     there were back references that the ovector was too small to contain
  434:     (causing temporary malloc'd memory to be used during matching), and the
  435:     highest capturing number was not used, memory off the end of the ovector
  436:     was incorrectly being set to -1. (It was using the size of the temporary
  437:     memory instead of the true size.)
  438: 
  439: 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
  440:     ovector size, it uses memory at the end of the block that it has got.
  441: 
  442: 29. Check for an overlong MARK name and give an error at compile time. The
  443:     limit is 255 for the 8-bit library and 65535 for the 16-bit library.
  444: 
  445: 30. JIT compiler update.
  446: 
  447: 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
  448:     Rill for the patch.
  449: 
  450: 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
  451: 
  452: 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
  453: 
  454: 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
  455:     SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
  456:     was enabled.
  457: 
  458: 35. Improve JIT code generation for greedy plus quantifier.
  459: 
  460: 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
  461:     1 to "aa" instead of to an empty string. The bug affected repeated groups
  462:     that could potentially match an empty string.
  463: 
  464: 37. Optimizing single character iterators in JIT.
  465: 
  466: 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
  467:     the same checks as \x{...} characters in non-JavaScript mode. Specifically,
  468:     codepoints that are too big for the mode are faulted, and in a UTF mode,
  469:     disallowed codepoints are also faulted.
  470: 
  471: 39. If PCRE was compiled with UTF support, in three places in the DFA
  472:     matcher there was code that should only have been obeyed in UTF mode, but
  473:     was being obeyed unconditionally. In 8-bit mode this could cause incorrect
  474:     processing when bytes with values greater than 127 were present. In 16-bit
  475:     mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
  476:     both cases the values are those that cannot be the first data item in a UTF
  477:     character. The three items that might have provoked this were recursions,
  478:     possessively repeated groups, and atomic groups.
  479: 
  480: 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
  481:     and pcregrep, because some OS require shared objects to be explicitly
  482:     passed to ld, causing the link step to fail if they are not.
  483: 
  484: 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
  485:     mode, patterns that started with \h* or \R* might be incorrectly matched.
  486: 
  487: 
  488: Version 8.30 04-February-2012
  489: -----------------------------
  490: 
  491: 1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
  492:     name is defined in ctype.h.
  493: 
  494: 2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
  495:     only in quite long subpatterns.
  496: 
  497: 3.  Removed the function pcre_info(), which has been obsolete and deprecated
  498:     since it was replaced by pcre_fullinfo() in February 2000.
  499: 
  500: 4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
  501:     match a (*MARK), and the match failed at the start of the subject, a
  502:     reference to memory before the start of the subject could occur. This bug
  503:     was introduced by fix 17 of release 8.21.
  504: 
  505: 5.  A reference to an unset group with zero minimum repetition was giving
  506:     totally wrong answers (in non-JavaScript-compatibility mode). For example,
  507:     /(another)?(\1?)test/ matched against "hello world test". This bug was
  508:     introduced in release 8.13.
  509: 
  510: 6.  Add support for 16-bit character strings (a large amount of work involving
  511:     many changes and refactorings).
  512: 
  513: 7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
  514:     command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
  515:     from a file.
  516: 
  517: 8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
  518:     rounding is not applied in this particular case).
  519: 
  520: 9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
  521:     if they appear, or are escaped, in patterns.
  522: 
  523: 10. Get rid of a number of -Wunused-but-set-variable warnings.
  524: 
  525: 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
  526:     "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
  527:     Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
  528:     also returns the mark "x". This bug applied to capturing parentheses,
  529:     non-capturing parentheses, and atomic parentheses. It also applied to some
  530:     assertions.
  531: 
  532: 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
  533:     information out of configure.ac instead of relying on pcre.h.generic, which
  534:     is not stored in the repository.
  535: 
  536: 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
  537:     -lreadline.
  538: 
  539: 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
  540: 
  541: 15. Applied Graycode's patch to put the top-level frame on the stack rather
  542:     than the heap when not using the stack for recursion. This gives a
  543:     performance improvement in many cases when recursion is not deep.
  544: 
  545: 16. Experimental code added to "pcretest -C" to output the stack frame size.
  546: 
  547: 
  548: Version 8.21 12-Dec-2011
  549: ------------------------
  550: 
  551: 1.  Updating the JIT compiler.
  552: 
  553: 2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
  554:     are added as well.
  555: 
  556: 3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
  557:     PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
  558:     calling _pcre_jit_exec. Some extra comments are added.
  559: 
  560: 4.  (*MARK) settings inside atomic groups that do not contain any capturing
  561:     parentheses, for example, (?>a(*:m)), were not being passed out. This bug
  562:     was introduced by change 18 for 8.20.
  563: 
  564: 5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
  565:     ECMA-262 standard.
  566: 
  567: 6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
  568:     erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
  569:     This bug was probably introduced by change 9 of 8.13.
  570: 
  571: 7.  While fixing 6 above, I noticed that a number of other items were being
  572:     incorrectly rejected as "not fixed length". This arose partly because newer
  573:     opcodes had not been added to the fixed-length checking code. I have (a)
  574:     corrected the bug and added tests for these items, and (b) arranged for an
  575:     error to occur if an unknown opcode is encountered while checking for fixed
  576:     length instead of just assuming "not fixed length". The items that were
  577:     rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
  578:     (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
  579:     repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
  580: 
  581: 8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
  582:     being incorrectly compiled and would have given unpredicatble results.
  583: 
  584: 9.  A possessively repeated subpattern with minimum repeat count greater than
  585:     one behaved incorrectly. For example, (A){2,}+ behaved as if it was
  586:     (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
  587:     the first (A) could occur when it should not.
  588: 
  589: 10. Add a cast and remove a redundant test from the code.
  590: 
  591: 11. JIT should use pcre_malloc/pcre_free for allocation.
  592: 
  593: 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
  594:     best practice nowadays, and helps with cross-compiling. (If the exec_prefix
  595:     is anything other than /usr, -L is still shown).
  596: 
  597: 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
  598: 
  599: 14. Perl does not support \N without a following name in a [] class; PCRE now
  600:     also gives an error.
  601: 
  602: 15. If a forward reference was repeated with an upper limit of around 2000,
  603:     it caused the error "internal error: overran compiling workspace". The
  604:     maximum number of forward references (including repeats) was limited by the
  605:     internal workspace, and dependent on the LINK_SIZE. The code has been
  606:     rewritten so that the workspace expands (via pcre_malloc) if necessary, and
  607:     the default depends on LINK_SIZE. There is a new upper limit (for safety)
  608:     of around 200,000 forward references. While doing this, I also speeded up
  609:     the filling in of repeated forward references.
  610: 
  611: 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
  612:     incorrectly expecting the subject to contain another "a" after the start.
  613: 
  614: 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
  615:     in the match, the SKIP should be ignored. This was not happening; instead
  616:     the SKIP was being treated as NOMATCH. For patterns such as
  617:     /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
  618:     tested.
  619: 
  620: 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
  621:     now much more compatible with Perl, in particular in cases where the result
  622:     is a non-match for a non-anchored pattern. For example, if
  623:     /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
  624:     "m", where previously it did not return a name. A side effect of this
  625:     change is that for partial matches, the last encountered mark name is
  626:     returned, as for non matches. A number of tests that were previously not
  627:     Perl-compatible have been moved into the Perl-compatible test files. The
  628:     refactoring has had the pleasing side effect of removing one argument from
  629:     the match() function, thus reducing its stack requirements.
  630: 
  631: 19. If the /S+ option was used in pcretest to study a pattern using JIT,
  632:     subsequent uses of /S (without +) incorrectly behaved like /S+.
  633: 
  634: 21. Retrieve executable code size support for the JIT compiler and fixing
  635:     some warnings.
  636: 
  637: 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
  638:     not work when the shorter character appeared right at the end of the
  639:     subject string.
  640: 
  641: 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
  642:     systems.
  643: 
  644: 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
  645:     output it when the /M option is used in pcretest.
  646: 
  647: 25. The CheckMan script was not being included in the distribution. Also, added
  648:     an explicit "perl" to run Perl scripts from the PrepareRelease script
  649:     because this is reportedly needed in Windows.
  650: 
  651: 26. If study data was being save in a file and studying had not found a set of
  652:     "starts with" bytes for the pattern, the data written to the file (though
  653:     never used) was taken from uninitialized memory and so caused valgrind to
  654:     complain.
  655: 
  656: 27. Updated RunTest.bat as provided by Sheri Pierce.
  657: 
  658: 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
  659: 
  660: 29. Computation of memory usage for the table of capturing group names was
  661:     giving an unnecessarily large value.
  662: 
  663: 
  664: Version 8.20 21-Oct-2011
  665: ------------------------
  666: 
  667: 1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
  668:     a POSIX class. After further experiments with Perl, which convinced me that
  669:     Perl has bugs and confusions, a closing square bracket is no longer allowed
  670:     in a POSIX name. This bug also affected patterns with classes that started
  671:     with full stops.
  672: 
  673: 2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
  674:     captured substring, but while checking the failing first alternative,
  675:     substring 1 is temporarily captured. If the output vector supplied to
  676:     pcre_exec() was not big enough for this capture, the yield of the function
  677:     was still zero ("insufficient space for captured substrings"). This cannot
  678:     be totally fixed without adding another stack variable, which seems a lot
  679:     of expense for a edge case. However, I have improved the situation in cases
  680:     such as /(a)(b)x|abc/ matched against "abc", where the return code
  681:     indicates that fewer than the maximum number of slots in the ovector have
  682:     been set.
  683: 
  684: 3.  Related to (2) above: when there are more back references in a pattern than
  685:     slots in the output vector, pcre_exec() uses temporary memory during
  686:     matching, and copies in the captures as far as possible afterwards. It was
  687:     using the entire output vector, but this conflicts with the specification
  688:     that only 2/3 is used for passing back captured substrings. Now it uses
  689:     only the first 2/3, for compatibility. This is, of course, another edge
  690:     case.
  691: 
  692: 4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
  693:     main code base, and can be used by building with --enable-jit. When this is
  694:     done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
  695:     runtime --no-jit option is given.
  696: 
  697: 5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
  698:     ovector, the return from the function was zero, implying that there were
  699:     other matches that did not fit. The correct "exactly full" value is now
  700:     returned.
  701: 
  702: 6.  If a subpattern that was called recursively or as a subroutine contained
  703:     (*PRUNE) or any other control that caused it to give a non-standard return,
  704:     invalid errors such as "Error -26 (nested recursion at the same subject
  705:     position)" or even infinite loops could occur.
  706: 
  707: 7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
  708:     computing the minimum length on reaching *ACCEPT, and so ended up with the
  709:     wrong value of 1 rather than 0. Further investigation indicates that
  710:     computing a minimum subject length in the presence of *ACCEPT is difficult
  711:     (think back references, subroutine calls), and so I have changed the code
  712:     so that no minimum is registered for a pattern that contains *ACCEPT.
  713: 
  714: 8.  If (*THEN) was present in the first (true) branch of a conditional group,
  715:     it was not handled as intended. [But see 16 below.]
  716: 
  717: 9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
  718:     Sheri Pierce.
  719: 
  720: 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
  721:     the first byte in a match must be "a".
  722: 
  723: 11. Change 17 for 8.13 increased the recursion depth for patterns like
  724:     /a(?:.)*?a/ drastically. I've improved things by remembering whether a
  725:     pattern contains any instances of (*THEN). If it does not, the old
  726:     optimizations are restored. It would be nice to do this on a per-group
  727:     basis, but at the moment that is not feasible.
  728: 
  729: 12. In some environments, the output of pcretest -C is CRLF terminated. This
  730:     broke RunTest's code that checks for the link size. A single white space
  731:     character after the value is now allowed for.
  732: 
  733: 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
  734:     For "fr", it uses the Windows-specific input and output files.
  735: 
  736: 14. If (*THEN) appeared in a group that was called recursively or as a
  737:     subroutine, it did not work as intended. [But see next item.]
  738: 
  739: 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
  740:     pattern fragments (but not containing any | characters). If A and B are
  741:     matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
  742:     was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
  743:     D. In other words, Perl considers parentheses that do not contain any |
  744:     characters to be part of a surrounding alternative, whereas PCRE was
  745:     treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
  746:     differently. PCRE now behaves in the same way as Perl, except in the case
  747:     of subroutine/recursion calls such as (?1) which have in any case always
  748:     been different (but PCRE had them first :-).
  749: 
  750: 16. Related to 15 above: Perl does not treat the | in a conditional group as
  751:     creating alternatives. Such a group is treated in the same way as an
  752:     ordinary group without any | characters when processing (*THEN). PCRE has
  753:     been changed to match Perl's behaviour.
  754: 
  755: 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
  756:     RunGrepTest script failed.
  757: 
  758: 18. Change 22 for version 13 caused atomic groups to use more stack. This is
  759:     inevitable for groups that contain captures, but it can lead to a lot of
  760:     stack use in large patterns. The old behaviour has been restored for atomic
  761:     groups that do not contain any capturing parentheses.
  762: 
  763: 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
  764:     suppress the check for a minimum subject length at run time. (If it was
  765:     given to pcre_exec() or pcre_dfa_exec() it did work.)
  766: 
  767: 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
  768:     fail to work when decoding hex characters in data strings in EBCDIC
  769:     environments.
  770: 
  771: 21. It appears that in at least one Mac OS environment, the isxdigit() function
  772:     is implemented as a macro that evaluates to its argument more than once,
  773:     contravening the C 90 Standard (I haven't checked a later standard). There
  774:     was an instance in pcretest which caused it to go wrong when processing
  775:     \x{...} escapes in subject strings. The has been rewritten to avoid using
  776:     things like p++ in the argument of isxdigit().
  777: 
  778: 
  779: Version 8.13 16-Aug-2011
  780: ------------------------
  781: 
  782: 1.  The Unicode data tables have been updated to Unicode 6.0.0.
  783: 
  784: 2.  Two minor typos in pcre_internal.h have been fixed.
  785: 
  786: 3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
  787:     pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
  788:     in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
  789: 
  790: 4.  There were a number of related bugs in the code for matching backrefences
  791:     caselessly in UTF-8 mode when codes for the characters concerned were
  792:     different numbers of bytes. For example, U+023A and U+2C65 are an upper
  793:     and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
  794:     (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
  795:     code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
  796:     2-byte code at the end of the subject (it thought there wasn't enough data
  797:     left).
  798: 
  799: 5.  Comprehensive information about what went wrong is now returned by
  800:     pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
  801:     as the output vector has at least 2 elements. The offset of the start of
  802:     the failing character and a reason code are placed in the vector.
  803: 
  804: 6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
  805:     now returned is for the first byte of the failing character, instead of the
  806:     last byte inspected. This is an incompatible change, but I hope it is small
  807:     enough not to be a problem. It makes the returned offset consistent with
  808:     pcre_exec() and pcre_dfa_exec().
  809: 
  810: 7.  pcretest now gives a text phrase as well as the error number when
  811:     pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
  812:     failure, the offset and reason code are output.
  813: 
  814: 8.  When \R was used with a maximizing quantifier it failed to skip backwards
  815:     over a \r\n pair if the subsequent match failed. Instead, it just skipped
  816:     back over a single character (\n). This seems wrong (because it treated the
  817:     two characters as a single entity when going forwards), conflicts with the
  818:     documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
  819:     behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
  820:     has been changed.
  821: 
  822: 9.  Some internal refactoring has changed the processing so that the handling
  823:     of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
  824:     time (the PCRE_DOTALL option was changed this way some time ago: version
  825:     7.7 change 16). This has made it possible to abolish the OP_OPT op code,
  826:     which was always a bit of a fudge. It also means that there is one less
  827:     argument for the match() function, which reduces its stack requirements
  828:     slightly. This change also fixes an incompatibility with Perl: the pattern
  829:     (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
  830: 
  831: 10. More internal refactoring has drastically reduced the number of recursive
  832:     calls to match() for possessively repeated groups such as (abc)++ when
  833:     using pcre_exec().
  834: 
  835: 11. While implementing 10, a number of bugs in the handling of groups were
  836:     discovered and fixed:
  837: 
  838:     (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
  839:     (a|)*(?1) gave a compile-time internal error.
  840:     ((a|)+)+  did not notice that the outer group could match an empty string.
  841:     (^a|^)+   was not marked as anchored.
  842:     (.*a|.*)+ was not marked as matching at start or after a newline.
  843: 
  844: 12. Yet more internal refactoring has removed another argument from the match()
  845:     function. Special calls to this function are now indicated by setting a
  846:     value in a variable in the "match data" data block.
  847: 
  848: 13. Be more explicit in pcre_study() instead of relying on "default" for
  849:     opcodes that mean there is no starting character; this means that when new
  850:     ones are added and accidentally left out of pcre_study(), testing should
  851:     pick them up.
  852: 
  853: 14. The -s option of pcretest has been documented for ages as being an old
  854:     synonym of -m (show memory usage). I have changed it to mean "force study
  855:     for every regex", that is, assume /S for every regex. This is similar to -i
  856:     and -d etc. It's slightly incompatible, but I'm hoping nobody is still
  857:     using it. It makes it easier to run collections of tests with and without
  858:     study enabled, and thereby test pcre_study() more easily. All the standard
  859:     tests are now run with and without -s (but some patterns can be marked as
  860:     "never study" - see 20 below).
  861: 
  862: 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
  863:     restoration of the capturing data to the outer values was not happening
  864:     correctly.
  865: 
  866: 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
  867:     empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
  868:     pattern had matched an empty string, and so incorrectly returned a no
  869:     match.
  870: 
  871: 17. There was optimizing code for the last branch of non-capturing parentheses,
  872:     and also for the obeyed branch of a conditional subexpression, which used
  873:     tail recursion to cut down on stack usage. Unfortunately, now that there is
  874:     the possibility of (*THEN) occurring in these branches, tail recursion is
  875:     no longer possible because the return has to be checked for (*THEN). These
  876:     two optimizations have therefore been removed. [But see 8.20/11 above.]
  877: 
  878: 18. If a pattern containing \R was studied, it was assumed that \R always
  879:     matched two bytes, thus causing the minimum subject length to be
  880:     incorrectly computed because \R can also match just one byte.
  881: 
  882: 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
  883:     was incorrectly computed.
  884: 
  885: 20. If /S is present twice on a test pattern in pcretest input, it now
  886:     *disables* studying, thereby overriding the use of -s on the command line
  887:     (see 14 above). This is necessary for one or two tests to keep the output
  888:     identical in both cases.
  889: 
  890: 21. When (*ACCEPT) was used in an assertion that matched an empty string and
  891:     PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
  892: 
  893: 22. When an atomic group that contained a capturing parenthesis was
  894:     successfully matched, but the branch in which it appeared failed, the
  895:     capturing was not being forgotten if a higher numbered group was later
  896:     captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
  897:     group 1 to "a", when in fact it should be unset. This applied to multi-
  898:     branched capturing and non-capturing groups, repeated or not, and also to
  899:     positive assertions (capturing in negative assertions does not happen
  900:     in PCRE) and also to nested atomic groups.
  901: 
  902: 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
  903:     subject after a captured substring, to make it easier to tell which of a
  904:     number of identical substrings has been captured.
  905: 
  906: 24. The way atomic groups are processed by pcre_exec() has been changed so that
  907:     if they are repeated, backtracking one repetition now resets captured
  908:     values correctly. For example, if ((?>(a+)b)+aabab) is matched against
  909:     "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
  910:     "aaa". Previously, it would have been "a". As part of this code
  911:     refactoring, the way recursive calls are handled has also been changed.
  912: 
  913: 25. If an assertion condition captured any substrings, they were not passed
  914:     back unless some other capturing happened later. For example, if
  915:     (?(?=(a))a) was matched against "a", no capturing was returned.
  916: 
  917: 26. When studying a pattern that contained subroutine calls or assertions,
  918:     the code for finding the minimum length of a possible match was handling
  919:     direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
  920:     group 1 called group 2 while simultaneously a separate group 2 called group
  921:     1). A stack overflow occurred in this case. I have fixed this by limiting
  922:     the recursion depth to 10.
  923: 
  924: 27. Updated RunTest.bat in the distribution to the version supplied by Tom
  925:     Fortmann. This supports explicit test numbers on the command line, and has
  926:     argument validation and error reporting.
  927: 
  928: 28. An instance of \X with an unlimited repeat could fail if at any point the
  929:     first character it looked at was a mark character.
  930: 
  931: 29. Some minor code refactoring concerning Unicode properties and scripts
  932:     should reduce the stack requirement of match() slightly.
  933: 
  934: 30. Added the '=' option to pcretest to check the setting of unused capturing
  935:     slots at the end of the pattern, which are documented as being -1, but are
  936:     not included in the return count.
  937: 
  938: 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
  939:     compiled something random. Now it gives a compile-time error (as does
  940:     Perl).
  941: 
  942: 32. A *MARK encountered during the processing of a positive assertion is now
  943:     recorded and passed back (compatible with Perl).
  944: 
  945: 33. If --only-matching or --colour was set on a pcregrep call whose pattern
  946:     had alternative anchored branches, the search for a second match in a line
  947:     was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
  948:     matched the line "0102" twice. The same bug affected patterns that started
  949:     with a backwards assertion. For example /\b01|\b02/ also matched "0102"
  950:     twice.
  951: 
  952: 34. Previously, PCRE did not allow quantification of assertions. However, Perl
  953:     does, and because of capturing effects, quantifying parenthesized
  954:     assertions may at times be useful. Quantifiers are now allowed for
  955:     parenthesized assertions.
  956: 
  957: 35. A minor code tidy in pcre_compile() when checking options for \R usage.
  958: 
  959: 36. \g was being checked for fancy things in a character class, when it should
  960:     just be a literal "g".
  961: 
  962: 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
  963:     appearance of a nested POSIX class supersedes an apparent external class.
  964:     For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
  965:     unescaped square brackets may also appear as part of class names. For
  966:     example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
  967:     more like Perl. (But see 8.20/1 above.)
  968: 
  969: 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
  970:     was because it thought it was \N{name}, which is not supported).
  971: 
  972: 39. Add minix to OS list not supporting the -S option in pcretest.
  973: 
  974: 40. PCRE tries to detect cases of infinite recursion at compile time, but it
  975:     cannot analyze patterns in sufficient detail to catch mutual recursions
  976:     such as ((?1))((?2)). There is now a runtime test that gives an error if a
  977:     subgroup is called recursively as a subpattern for a second time at the
  978:     same position in the subject string. In previous releases this might have
  979:     been caught by the recursion limit, or it might have run out of stack.
  980: 
  981: 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
  982:     happen only once. PCRE was, however incorrectly giving a compile time error
  983:     "recursive call could loop indefinitely" because it cannot analyze the
  984:     pattern in sufficient detail. The compile time test no longer happens when
  985:     PCRE is compiling a conditional subpattern, but actual runaway loops are
  986:     now caught at runtime (see 40 above).
  987: 
  988: 42. It seems that Perl allows any characters other than a closing parenthesis
  989:     to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
  990:     has been changed to be the same.
  991: 
  992: 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
  993:     as not to get warnings when autogen.sh is called. Also changed
  994:     AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
  995: 
  996: 44. To help people who use pcregrep to scan files containing exceedingly long
  997:     lines, the following changes have been made:
  998: 
  999:     (a) The default value of the buffer size parameter has been increased from
 1000:         8K to 20K. (The actual buffer used is three times this size.)
 1001: 
 1002:     (b) The default can be changed by ./configure --with-pcregrep-bufsize when
 1003:         PCRE is built.
 1004: 
 1005:     (c) A --buffer-size=n option has been added to pcregrep, to allow the size
 1006:         to be set at run time.
 1007: 
 1008:     (d) Numerical values in pcregrep options can be followed by K or M, for
 1009:         example --buffer-size=50K.
 1010: 
 1011:     (e) If a line being scanned overflows pcregrep's buffer, an error is now
 1012:         given and the return code is set to 2.
 1013: 
 1014: 45. Add a pointer to the latest mark to the callout data block.
 1015: 
 1016: 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
 1017:     partial match of an empty string instead of no match. This was specific to
 1018:     the use of ".".
 1019: 
 1020: 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
 1021:     complete match instead of a partial match. This bug was dependent on both
 1022:     the PCRE_UTF8 and PCRE_DOTALL options being set.
 1023: 
 1024: 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
 1025:     starting byte set, because \b was not being ignored.
 1026: 
 1027: 
 1028: Version 8.12 15-Jan-2011
 1029: ------------------------
 1030: 
 1031: 1.  Fixed some typos in the markup of the man pages, and wrote a script that
 1032:     checks for such things as part of the documentation building process.
 1033: 
 1034: 2.  On a big-endian 64-bit system, pcregrep did not correctly process the
 1035:     --match-limit and --recursion-limit options (added for 8.11). In
 1036:     particular, this made one of the standard tests fail. (The integer value
 1037:     went into the wrong half of a long int.)
 1038: 
 1039: 3.  If the --colour option was given to pcregrep with -v (invert match), it
 1040:     did strange things, either producing crazy output, or crashing. It should,
 1041:     of course, ignore a request for colour when reporting lines that do not
 1042:     match.
 1043: 
 1044: 4.  Another pcregrep bug caused similar problems if --colour was specified with
 1045:     -M (multiline) and the pattern match finished with a line ending.
 1046: 
 1047: 5.  In pcregrep, when a pattern that ended with a literal newline sequence was
 1048:     matched in multiline mode, the following line was shown as part of the
 1049:     match. This seems wrong, so I have changed it.
 1050: 
 1051: 6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
 1052:     the check for further matches in the same line (so they could be coloured)
 1053:     to overrun the end of the current line. If another match was found, it was
 1054:     incorrectly shown (and then shown again when found in the next line).
 1055: 
 1056: 7.  If pcregrep was compiled under Windows, there was a reference to the
 1057:     function pcregrep_exit() before it was defined. I am assuming this was
 1058:     the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
 1059:     reported by a user. I've moved the definition above the reference.
 1060: 
 1061: 
 1062: Version 8.11 10-Dec-2010
 1063: ------------------------
 1064: 
 1065: 1.  (*THEN) was not working properly if there were untried alternatives prior
 1066:     to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
 1067:     backtracked to try for "b" instead of moving to the next alternative branch
 1068:     at the same level (in this case, to look for "c"). The Perl documentation
 1069:     is clear that when (*THEN) is backtracked onto, it goes to the "next
 1070:     alternative in the innermost enclosing group".
 1071: 
 1072: 2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
 1073:     such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
 1074:     result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
 1075:     (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
 1076:     (*THEN).
 1077: 
 1078: 3.  If \s appeared in a character class, it removed the VT character from
 1079:     the class, even if it had been included by some previous item, for example
 1080:     in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
 1081:     of \s, but is part of the POSIX "space" class.)
 1082: 
 1083: 4.  A partial match never returns an empty string (because you can always
 1084:     match an empty string at the end of the subject); however the checking for
 1085:     an empty string was starting at the "start of match" point. This has been
 1086:     changed to the "earliest inspected character" point, because the returned
 1087:     data for a partial match starts at this character. This means that, for
 1088:     example, /(?<=abc)def/ gives a partial match for the subject "abc"
 1089:     (previously it gave "no match").
 1090: 
 1091: 5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
 1092:     of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
 1093:     previously a full match would be given. However, setting PCRE_PARTIAL_HARD
 1094:     has an implication that the given string is incomplete (because a partial
 1095:     match is preferred over a full match). For this reason, these items now
 1096:     give a partial match in this situation. [Aside: previously, the one case
 1097:     /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
 1098:     match rather than a full match, which was wrong by the old rules, but is
 1099:     now correct.]
 1100: 
 1101: 6.  There was a bug in the handling of #-introduced comments, recognized when
 1102:     PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
 1103:     If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
 1104:     UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
 1105:     scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
 1106:     but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
 1107:     places in pcre_compile().
 1108: 
 1109: 7.  Related to (6) above, when pcre_compile() was skipping #-introduced
 1110:     comments when looking ahead for named forward references to subpatterns,
 1111:     the only newline sequence it recognized was NL. It now handles newlines
 1112:     according to the set newline convention.
 1113: 
 1114: 8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
 1115:     former, but used strtoul(), whereas pcretest avoided strtoul() but did not
 1116:     cater for a lack of strerror(). These oversights have been fixed.
 1117: 
 1118: 9.  Added --match-limit and --recursion-limit to pcregrep.
 1119: 
 1120: 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
 1121: 
 1122: 11. When the -o option was used, pcregrep was setting a return code of 1, even
 1123:     when matches were found, and --line-buffered was not being honoured.
 1124: 
 1125: 12. Added an optional parentheses number to the -o and --only-matching options
 1126:     of pcregrep.
 1127: 
 1128: 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
 1129:     can match an empty string. The code to do it in pcretest and pcredemo
 1130:     needed fixing:
 1131: 
 1132:     (a) When the newline convention was "crlf", pcretest got it wrong, skipping
 1133:         only one byte after an empty string match just before CRLF (this case
 1134:         just got forgotten; "any" and "anycrlf" were OK).
 1135: 
 1136:     (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
 1137:         mode when an empty string match preceded an ASCII character followed by
 1138:         a non-ASCII character. (The code for advancing by one character rather
 1139:         than one byte was nonsense.)
 1140: 
 1141:     (c) The pcredemo.c sample program did not have any code at all to handle
 1142:         the cases when CRLF is a valid newline sequence.
 1143: 
 1144: 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
 1145:     as a starting offset was within the subject string. There is now a new
 1146:     error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
 1147:     negative or greater than the length of the string. In order to test this,
 1148:     pcretest is extended to allow the setting of negative starting offsets.
 1149: 
 1150: 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
 1151:     starting offset points to the beginning of a UTF-8 character was
 1152:     unnecessarily clumsy. I tidied it up.
 1153: 
 1154: 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
 1155:     bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
 1156: 
 1157: 17. Nobody had reported that the --include_dir option, which was added in
 1158:     release 7.7 should have been called --include-dir (hyphen, not underscore)
 1159:     for compatibility with GNU grep. I have changed it to --include-dir, but
 1160:     left --include_dir as an undocumented synonym, and the same for
 1161:     --exclude-dir, though that is not available in GNU grep, at least as of
 1162:     release 2.5.4.
 1163: 
 1164: 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
 1165:     characters from a string of bytes) have been redefined so as not to use
 1166:     loops, in order to improve performance in some environments. At the same
 1167:     time, I abstracted some of the common code into auxiliary macros to save
 1168:     repetition (this should not affect the compiled code).
 1169: 
 1170: 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
 1171:     compile-time error is now given if \c is not followed by an ASCII
 1172:     character, that is, a byte less than 128. (In EBCDIC mode, the code is
 1173:     different, and any byte value is allowed.)
 1174: 
 1175: 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
 1176:     START_OPTIMIZE option, which is now allowed at compile time - but just
 1177:     passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
 1178:     to pcregrep and other applications that have no direct access to PCRE
 1179:     options. The new /Y option in pcretest sets this option when calling
 1180:     pcre_compile().
 1181: 
 1182: 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
 1183:     back references. Groups containing recursive back references were forced to
 1184:     be atomic by that change, but in the case of named groups, the amount of
 1185:     memory required was incorrectly computed, leading to "Failed: internal
 1186:     error: code overflow". This has been fixed.
 1187: 
 1188: 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
 1189:     pcretest.c, to avoid build problems in some Borland environments.
 1190: 
 1191: 
 1192: Version 8.10 25-Jun-2010
 1193: ------------------------
 1194: 
 1195: 1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
 1196:     THEN.
 1197: 
 1198: 2.  (*ACCEPT) was not working when inside an atomic group.
 1199: 
 1200: 3.  Inside a character class, \B is treated as a literal by default, but
 1201:     faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
 1202:     causes the error). The code is unchanged, but I tidied the documentation.
 1203: 
 1204: 4.  Inside a character class, PCRE always treated \R and \X as literals,
 1205:     whereas Perl faults them if its -w option is set. I have changed PCRE so
 1206:     that it faults them when PCRE_EXTRA is set.
 1207: 
 1208: 5.  Added support for \N, which always matches any character other than
 1209:     newline. (It is the same as "." when PCRE_DOTALL is not set.)
 1210: 
 1211: 6.  When compiling pcregrep with newer versions of gcc which may have
 1212:     FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
 1213:     declared with attribute warn_unused_result" were given. Just casting the
 1214:     result to (void) does not stop the warnings; a more elaborate fudge is
 1215:     needed. I've used a macro to implement this.
 1216: 
 1217: 7.  Minor change to pcretest.c to avoid a compiler warning.
 1218: 
 1219: 8.  Added four artifical Unicode properties to help with an option to make
 1220:     \s etc use properties (see next item). The new properties are: Xan
 1221:     (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
 1222: 
 1223: 9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
 1224:     use Unicode properties. (*UCP) at the start of a pattern can be used to set
 1225:     this option. Modified pcretest to add /W to test this facility. Added
 1226:     REG_UCP to make it available via the POSIX interface.
 1227: 
 1228: 10. Added --line-buffered to pcregrep.
 1229: 
 1230: 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
 1231:     studied, and the match started with a letter with a code point greater than
 1232:     127 whose first byte was different to the first byte of the other case of
 1233:     the letter, the other case of this starting letter was not recognized
 1234:     (#976).
 1235: 
 1236: 12. If a pattern that was studied started with a repeated Unicode property
 1237:     test, for example, \p{Nd}+, there was the theoretical possibility of
 1238:     setting up an incorrect bitmap of starting bytes, but fortunately it could
 1239:     not have actually happened in practice until change 8 above was made (it
 1240:     added property types that matched character-matching opcodes).
 1241: 
 1242: 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
 1243:     possible starting bytes for non-anchored patterns.
 1244: 
 1245: 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
 1246:     \R, and also a number of cases that involve Unicode properties, both
 1247:     explicit and implicit when PCRE_UCP is set.
 1248: 
 1249: 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
 1250:     input, it could crash or give wrong results if characters with values
 1251:     greater than 0xc0 were present in the subject string. (Detail: it assumed
 1252:     UTF-8 input when processing these items.)
 1253: 
 1254: 16. Added a lot of (int) casts to avoid compiler warnings in systems where
 1255:     size_t is 64-bit (#991).
 1256: 
 1257: 17. Added a check for running out of memory when PCRE is compiled with
 1258:     --disable-stack-for-recursion (#990).
 1259: 
 1260: 18. If the last data line in a file for pcretest does not have a newline on
 1261:     the end, a newline was missing in the output.
 1262: 
 1263: 19. The default pcre_chartables.c file recognizes only ASCII characters (values
 1264:     less than 128) in its various bitmaps. However, there is a facility for
 1265:     generating tables according to the current locale when PCRE is compiled. It
 1266:     turns out that in some environments, 0x85 and 0xa0, which are Unicode space
 1267:     characters, are recognized by isspace() and therefore were getting set in
 1268:     these tables, and indeed these tables seem to approximate to ISO 8859. This
 1269:     caused a problem in UTF-8 mode when pcre_study() was used to create a list
 1270:     of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
 1271:     which of course cannot start UTF-8 characters. I have changed the code so
 1272:     that only real ASCII characters (less than 128) and the correct starting
 1273:     bytes for UTF-8 encodings are set for characters greater than 127 when in
 1274:     UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
 1275:     altogether.)
 1276: 
 1277: 20. Added the /T option to pcretest so as to be able to run tests with non-
 1278:     standard character tables, thus making it possible to include the tests
 1279:     used for 19 above in the standard set of tests.
 1280: 
 1281: 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
 1282:     reference to a subpattern the other side of a comment that contains an
 1283:     opening parenthesis caused either an internal compiling error, or a
 1284:     reference to the wrong subpattern.
 1285: 
 1286: 
 1287: Version 8.02 19-Mar-2010
 1288: ------------------------
 1289: 
 1290: 1.  The Unicode data tables have been updated to Unicode 5.2.0.
 1291: 
 1292: 2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
 1293:     configured.
 1294: 
 1295: 3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
 1296:     original author of that file, following a query about its status.
 1297: 
 1298: 4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
 1299:     inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
 1300: 
 1301: 5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
 1302:     quantifier applied to a forward-referencing subroutine call, could compile
 1303:     incorrect code or give the error "internal error: previously-checked
 1304:     referenced subpattern not found".
 1305: 
 1306: 6.  Both MS Visual Studio and Symbian OS have problems with initializing
 1307:     variables to point to external functions. For these systems, therefore,
 1308:     pcre_malloc etc. are now initialized to local functions that call the
 1309:     relevant global functions.
 1310: 
 1311: 7.  There were two entries missing in the vectors called coptable and poptable
 1312:     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
 1313:     I've fixed the data, and added a kludgy way of testing at compile time that
 1314:     the lengths are correct (equal to the number of opcodes).
 1315: 
 1316: 8.  Following on from 7, I added a similar kludge to check the length of the
 1317:     eint vector in pcreposix.c.
 1318: 
 1319: 9.  Error texts for pcre_compile() are held as one long string to avoid too
 1320:     much relocation at load time. To find a text, the string is searched,
 1321:     counting zeros. There was no check for running off the end of the string,
 1322:     which could happen if a new error number was added without updating the
 1323:     string.
 1324: 
 1325: 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
 1326: 
 1327: 11. \K was not working if it appeared in an atomic group or in a group that
 1328:     was called as a "subroutine", or in an assertion. Perl 5.11 documents that
 1329:     \K is "not well defined" if used in an assertion. PCRE now accepts it if
 1330:     the assertion is positive, but not if it is negative.
 1331: 
 1332: 12. Change 11 fortuitously reduced the size of the stack frame used in the
 1333:     "match()" function of pcre_exec.c by one pointer. Forthcoming
 1334:     implementation of support for (*MARK) will need an extra pointer on the
 1335:     stack; I have reserved it now, so that the stack frame size does not
 1336:     decrease.
 1337: 
 1338: 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
 1339:     item in branch that calls a recursion is a subroutine call - as in the
 1340:     second branch in the above example - was incorrectly given the compile-
 1341:     time error "recursive call could loop indefinitely" because pcre_compile()
 1342:     was not correctly checking the subroutine for matching a non-empty string.
 1343: 
 1344: 14. The checks for overrunning compiling workspace could trigger after an
 1345:     overrun had occurred. This is a "should never occur" error, but it can be
 1346:     triggered by pathological patterns such as hundreds of nested parentheses.
 1347:     The checks now trigger 100 bytes before the end of the workspace.
 1348: 
 1349: 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
 1350: 
 1351: 
 1352: Version 8.01 19-Jan-2010
 1353: ------------------------
 1354: 
 1355: 1.  If a pattern contained a conditional subpattern with only one branch (in
 1356:     particular, this includes all (*DEFINE) patterns), a call to pcre_study()
 1357:     computed the wrong minimum data length (which is of course zero for such
 1358:     subpatterns). This could cause incorrect "no match" results.
 1359: 
 1360: 2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
 1361:     the pattern is reset in the first branch, pcre_compile() failed with
 1362:     "internal error: code overflow at offset...". This happened only when
 1363:     the reset was to the original external option setting. (An optimization
 1364:     abstracts leading options settings into an external setting, which was the
 1365:     cause of this.)
 1366: 
 1367: 3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
 1368:     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
 1369:     assertion pattern did not match (meaning that the assertion was true), it
 1370:     was incorrectly treated as false if the SKIP had been reached during the
 1371:     matching. This also applied to assertions used as conditions.
 1372: 
 1373: 4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
 1374:     assertion subpattern, including such a pattern used as a condition,
 1375:     unpredictable results occurred, instead of the error return
 1376:     PCRE_ERROR_DFA_UITEM.
 1377: 
 1378: 5.  The C++ GlobalReplace function was not working like Perl for the special
 1379:     situation when an empty string is matched. It now does the fancy magic
 1380:     stuff that is necessary.
 1381: 
 1382: 6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
 1383:     removed. (These were left over from very, very early versions of PCRE.)
 1384: 
 1385: 7.  Some cosmetic changes to the code to make life easier when compiling it
 1386:     as part of something else:
 1387: 
 1388:     (a) Change DEBUG to PCRE_DEBUG.
 1389: 
 1390:     (b) In pcre_compile(), rename the member of the "branch_chain" structure
 1391:         called "current" as "current_branch", to prevent a collision with the
 1392:         Linux macro when compiled as a kernel module.
 1393: 
 1394:     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
 1395:         prevent a collision with the Linux macro when compiled as a kernel
 1396:         module.
 1397: 
 1398: 8.  In pcre_compile() there are some checks for integer overflows that used to
 1399:     cast potentially large values to (double). This has been changed to that
 1400:     when building, a check for int64_t is made, and if it is found, it is used
 1401:     instead, thus avoiding the use of floating point arithmetic. (There is no
 1402:     other use of FP in PCRE.) If int64_t is not found, the fallback is to
 1403:     double.
 1404: 
 1405: 9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
 1406:     2005 (difference between two addresses compared to an unsigned value).
 1407: 
 1408: 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
 1409:     custom one, because of the following reported problem in Windows:
 1410: 
 1411:       - libbz2 uses the Pascal calling convention (WINAPI) for the functions
 1412:           under Win32.
 1413:       - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
 1414:           therefore missing the function definition.
 1415:       - The compiler thus generates a "C" signature for the test function.
 1416:       - The linker fails to find the "C" function.
 1417:       - PCRE fails to configure if asked to do so against libbz2.
 1418: 
 1419: 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
 1420:     messages were output:
 1421: 
 1422:       Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
 1423:       rerunning libtoolize, to keep the correct libtool macros in-tree.
 1424:       Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
 1425: 
 1426:     I have done both of these things.
 1427: 
 1428: 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
 1429:     most of the time, it *can* run out if it is given a pattern that contains a
 1430:     runaway infinite recursion. I updated the discussion in the pcrestack man
 1431:     page.
 1432: 
 1433: 13. Now that we have gone to the x.xx style of version numbers, the minor
 1434:     version may start with zero. Using 08 or 09 is a bad idea because users
 1435:     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
 1436:     interpreted as invalid octal numbers. I've updated the previous comment in
 1437:     configure.ac, and also added a check that gives an error if 08 or 09 are
 1438:     used.
 1439: 
 1440: 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
 1441:     causing partial matching to fail when the end of the subject matched \W
 1442:     in a UTF-8 pattern where \W was quantified with a minimum of 3.
 1443: 
 1444: 15. There were some discrepancies between the declarations in pcre_internal.h
 1445:     of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
 1446:     their definitions. The declarations used "const uschar *" and the
 1447:     definitions used USPTR. Even though USPTR is normally defined as "const
 1448:     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
 1449:     reported that: "This difference in casting confuses some C++ compilers, for
 1450:     example, SunCC recognizes above declarations as different functions and
 1451:     generates broken code for hbpcre." I have changed the declarations to use
 1452:     USPTR.
 1453: 
 1454: 16. GNU libtool is named differently on some systems. The autogen.sh script now
 1455:     tries several variants such as glibtoolize (MacOSX) and libtoolize1x
 1456:     (FreeBSD).
 1457: 
 1458: 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
 1459:     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
 1460:     comment: "Figure out how to create a longlong from a string: strtoll and
 1461:     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
 1462:     instance, but it only takes 2 args instead of 3!"
 1463: 
 1464: 18. A subtle bug concerned with back references has been fixed by a change of
 1465:     specification, with a corresponding code fix. A pattern such as
 1466:     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
 1467:     refers, was giving matches when it shouldn't. For example, xa=xaaa would
 1468:     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
 1469:     same bug. Such groups have to be quantified to be useful, or contained
 1470:     inside another quantified group. (If there's no repetition, the reference
 1471:     can never match.) The problem arises because, having left the group and
 1472:     moved on to the rest of the pattern, a later failure that backtracks into
 1473:     the group uses the captured value from the final iteration of the group
 1474:     rather than the correct earlier one. I have fixed this in PCRE by forcing
 1475:     any group that contains a reference to itself to be an atomic group; that
 1476:     is, there cannot be any backtracking into it once it has completed. This is
 1477:     similar to recursive and subroutine calls.
 1478: 
 1479: 
 1480: Version 8.00 19-Oct-09
 1481: ----------------------
 1482: 
 1483: 1.  The table for translating pcre_compile() error codes into POSIX error codes
 1484:     was out-of-date, and there was no check on the pcre_compile() error code
 1485:     being within the table. This could lead to an OK return being given in
 1486:     error.
 1487: 
 1488: 2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
 1489:     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
 1490:     in a Windows environment.
 1491: 
 1492: 3.  The pcregrep --count option prints the count for each file even when it is
 1493:     zero, as does GNU grep. However, pcregrep was also printing all files when
 1494:     --files-with-matches was added. Now, when both options are given, it prints
 1495:     counts only for those files that have at least one match. (GNU grep just
 1496:     prints the file name in this circumstance, but including the count seems
 1497:     more useful - otherwise, why use --count?) Also ensured that the
 1498:     combination -clh just lists non-zero counts, with no names.
 1499: 
 1500: 4.  The long form of the pcregrep -F option was incorrectly implemented as
 1501:     --fixed_strings instead of --fixed-strings. This is an incompatible change,
 1502:     but it seems right to fix it, and I didn't think it was worth preserving
 1503:     the old behaviour.
 1504: 
 1505: 5.  The command line items --regex=pattern and --regexp=pattern were not
 1506:     recognized by pcregrep, which required --regex pattern or --regexp pattern
 1507:     (with a space rather than an '='). The man page documented the '=' forms,
 1508:     which are compatible with GNU grep; these now work.
 1509: 
 1510: 6.  No libpcreposix.pc file was created for pkg-config; there was just
 1511:     libpcre.pc and libpcrecpp.pc. The omission has been rectified.
 1512: 
 1513: 7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
 1514:     when UCP support is not needed, by modifying the Python script that
 1515:     generates it from Unicode data files. This should not matter if the module
 1516:     is correctly used as a library, but I received one complaint about 50K of
 1517:     unwanted data. My guess is that the person linked everything into his
 1518:     program rather than using a library. Anyway, it does no harm.
 1519: 
 1520: 8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
 1521:     was a minimum greater than 1 for a wide character in a possessive
 1522:     repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
 1523:     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
 1524:     character. Chaos in the form of incorrect output or a compiling loop could
 1525:     result.
 1526: 
 1527: 9.  The restrictions on what a pattern can contain when partial matching is
 1528:     requested for pcre_exec() have been removed. All patterns can now be
 1529:     partially matched by this function. In addition, if there are at least two
 1530:     slots in the offset vector, the offset of the earliest inspected character
 1531:     for the match and the offset of the end of the subject are set in them when
 1532:     PCRE_ERROR_PARTIAL is returned.
 1533: 
 1534: 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
 1535:     synonymous with PCRE_PARTIAL, for backwards compatibility, and
 1536:     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
 1537:     and may be more useful for multi-segment matching.
 1538: 
 1539: 11. Partial matching with pcre_exec() is now more intuitive. A partial match
 1540:     used to be given if ever the end of the subject was reached; now it is
 1541:     given only if matching could not proceed because another character was
 1542:     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
 1543:     string "Z", which now yields "no match" instead of "partial match". In the
 1544:     case of pcre_dfa_exec(), "no match" is given if every matching path for the
 1545:     final character ended with (*FAIL).
 1546: 
 1547: 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
 1548:     if the pattern had a "must contain" character that was already found in the
 1549:     earlier partial match, unless partial matching was again requested. For
 1550:     example, with the pattern /dog.(body)?/, the "must contain" character is
 1551:     "g". If the first part-match was for the string "dog", restarting with
 1552:     "sbody" failed. This bug has been fixed.
 1553: 
 1554: 13. The string returned by pcre_dfa_exec() after a partial match has been
 1555:     changed so that it starts at the first inspected character rather than the
 1556:     first character of the match. This makes a difference only if the pattern
 1557:     starts with a lookbehind assertion or \b or \B (\K is not supported by
 1558:     pcre_dfa_exec()). It's an incompatible change, but it makes the two
 1559:     matching functions compatible, and I think it's the right thing to do.
 1560: 
 1561: 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
 1562:     so that the demonstration program is easily available in environments where
 1563:     PCRE has not been installed from source.
 1564: 
 1565: 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
 1566:     libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
 1567:     library.
 1568: 
 1569: 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
 1570:     It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
 1571:     is not the first non-POSIX option to be added. Clearly some people find
 1572:     these options useful.
 1573: 
 1574: 17. If a caller to the POSIX matching function regexec() passes a non-zero
 1575:     value for nmatch with a NULL value for pmatch, the value of
 1576:     nmatch is forced to zero.
 1577: 
 1578: 18. RunGrepTest did not have a test for the availability of the -u option of
 1579:     the diff command, as RunTest does. It now checks in the same way as
 1580:     RunTest, and also checks for the -b option.
 1581: 
 1582: 19. If an odd number of negated classes containing just a single character
 1583:     interposed, within parentheses, between a forward reference to a named
 1584:     subpattern and the definition of the subpattern, compilation crashed with
 1585:     an internal error, complaining that it could not find the referenced
 1586:     subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
 1587:     [The bug was that it was starting one character too far in when skipping
 1588:     over the character class, thus treating the ] as data rather than
 1589:     terminating the class. This meant it could skip too much.]
 1590: 
 1591: 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
 1592:     /g option in pcretest when the pattern contains \K, which makes it possible
 1593:     to have an empty string match not at the start, even when the pattern is
 1594:     anchored. Updated pcretest and pcredemo to use this option.
 1595: 
 1596: 21. If the maximum number of capturing subpatterns in a recursion was greater
 1597:     than the maximum at the outer level, the higher number was returned, but
 1598:     with unset values at the outer level. The correct (outer level) value is
 1599:     now given.
 1600: 
 1601: 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
 1602:     PCRE did not set those parentheses (unlike Perl). I have now found a way to
 1603:     make it do so. The string so far is captured, making this feature
 1604:     compatible with Perl.
 1605: 
 1606: 23. The tests have been re-organized, adding tests 11 and 12, to make it
 1607:     possible to check the Perl 5.10 features against Perl 5.10.
 1608: 
 1609: 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
 1610:     pattern matches a fixed length string. PCRE did not allow this; now it
 1611:     does. Neither allows recursion.
 1612: 
 1613: 25. I finally figured out how to implement a request to provide the minimum
 1614:     length of subject string that was needed in order to match a given pattern.
 1615:     (It was back references and recursion that I had previously got hung up
 1616:     on.) This code has now been added to pcre_study(); it finds a lower bound
 1617:     to the length of subject needed. It is not necessarily the greatest lower
 1618:     bound, but using it to avoid searching strings that are too short does give
 1619:     some useful speed-ups. The value is available to calling programs via
 1620:     pcre_fullinfo().
 1621: 
 1622: 26. While implementing 25, I discovered to my embarrassment that pcretest had
 1623:     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
 1624:     study optimizations had never been tested with that matching function.
 1625:     Oops. What is worse, even when it was passed study data, there was a bug in
 1626:     pcre_dfa_exec() that meant it never actually used it. Double oops. There
 1627:     were also very few tests of studied patterns with pcre_dfa_exec().
 1628: 
 1629: 27. If (?| is used to create subpatterns with duplicate numbers, they are now
 1630:     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
 1631:     on the other side of the coin, they are no longer allowed to have different
 1632:     names, because these cannot be distinguished in PCRE, and this has caused
 1633:     confusion. (This is a difference from Perl.)
 1634: 
 1635: 28. When duplicate subpattern names are present (necessarily with different
 1636:     numbers, as required by 27 above), and a test is made by name in a
 1637:     conditional pattern, either for a subpattern having been matched, or for
 1638:     recursion in such a pattern, all the associated numbered subpatterns are
 1639:     tested, and the overall condition is true if the condition is true for any
 1640:     one of them. This is the way Perl works, and is also more like the way
 1641:     testing by number works.
 1642: 
 1643: 
 1644: Version 7.9 11-Apr-09
 1645: ---------------------
 1646: 
 1647: 1.  When building with support for bzlib/zlib (pcregrep) and/or readline
 1648:     (pcretest), all targets were linked against these libraries. This included
 1649:     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
 1650:     libraries. This caused unwanted dependencies to be created. This problem
 1651:     has been fixed, and now only pcregrep is linked with bzlib/zlib and only
 1652:     pcretest is linked with readline.
 1653: 
 1654: 2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
 1655:     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
 1656:     moved outside it again, because FALSE and TRUE are already defined in AIX,
 1657:     but BOOL is not.
 1658: 
 1659: 3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
 1660:     PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
 1661: 
 1662: 4.  The pcregrep documentation said spaces were inserted as well as colons (or
 1663:     hyphens) following file names and line numbers when outputting matching
 1664:     lines. This is not true; no spaces are inserted. I have also clarified the
 1665:     wording for the --colour (or --color) option.
 1666: 
 1667: 5.  In pcregrep, when --colour was used with -o, the list of matching strings
 1668:     was not coloured; this is different to GNU grep, so I have changed it to be
 1669:     the same.
 1670: 
 1671: 6.  When --colo(u)r was used in pcregrep, only the first matching substring in
 1672:     each matching line was coloured. Now it goes on to look for further matches
 1673:     of any of the test patterns, which is the same behaviour as GNU grep.
 1674: 
 1675: 7.  A pattern that could match an empty string could cause pcregrep to loop; it
 1676:     doesn't make sense to accept an empty string match in pcregrep, so I have
 1677:     locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
 1678:     seems to be how GNU grep behaves. [But see later change 40 for release
 1679:     8.33.]
 1680: 
 1681: 8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
 1682:     start or after a newline", because the conditional assertion was not being
 1683:     correctly handled. The rule now is that both the assertion and what follows
 1684:     in the first alternative must satisfy the test.
 1685: 
 1686: 9.  If auto-callout was enabled in a pattern with a conditional group whose
 1687:     condition was an assertion, PCRE could crash during matching, both with
 1688:     pcre_exec() and pcre_dfa_exec().
 1689: 
 1690: 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
 1691:     used for matching.
 1692: 
 1693: 11. Unicode property support in character classes was not working for
 1694:     characters (bytes) greater than 127 when not in UTF-8 mode.
 1695: 
 1696: 12. Added the -M command line option to pcretest.
 1697: 
 1698: 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
 1699: 
 1700: 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
 1701: 
 1702: 16. Added comments and documentation about mis-use of no_arg in the C++
 1703:     wrapper.
 1704: 
 1705: 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
 1706:     from Martin Jerabek that uses macro names for all relevant character and
 1707:     string constants.
 1708: 
 1709: 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
 1710:     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
 1711:     SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
 1712:     these, but not everybody uses configure.
 1713: 
 1714: 19. A conditional group that had only one branch was not being correctly
 1715:     recognized as an item that could match an empty string. This meant that an
 1716:     enclosing group might also not be so recognized, causing infinite looping
 1717:     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
 1718:     with the subject "ab", where knowledge that the repeated group can match
 1719:     nothing is needed in order to break the loop.
 1720: 
 1721: 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
 1722:     exec(), but without supplying a callout function, matching went wrong.
 1723: 
 1724: 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
 1725:     leak if the size of the offset vector was greater than 30. When the vector
 1726:     is smaller, the saved offsets during recursion go onto a local stack
 1727:     vector, but for larger vectors malloc() is used. It was failing to free
 1728:     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
 1729:     error, in fact).
 1730: 
 1731: 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
 1732:     heapframe that is used only when UTF-8 support is enabled. This caused no
 1733:     problem, but was untidy.
 1734: 
 1735: 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
 1736:     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
 1737:     included within another project.
 1738: 
 1739: 24. Steven Van Ingelgem's patches to add more options to the CMake support,
 1740:     slightly modified by me:
 1741: 
 1742:       (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
 1743:           not building pcregrep.
 1744: 
 1745:       (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
 1746:           if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
 1747: 
 1748: 25. Forward references, both numeric and by name, in patterns that made use of
 1749:     duplicate group numbers, could behave incorrectly or give incorrect errors,
 1750:     because when scanning forward to find the reference group, PCRE was not
 1751:     taking into account the duplicate group numbers. A pattern such as
 1752:     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
 1753: 
 1754: 26. Changed a few more instances of "const unsigned char *" to USPTR, making
 1755:     the feature of a custom pointer more persuasive (as requested by a user).
 1756: 
 1757: 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
 1758:     pcretest.c, inside #ifndefs, because it seems they are sometimes already
 1759:     pre-defined.
 1760: 
 1761: 28. Added support for (*UTF8) at the start of a pattern.
 1762: 
 1763: 29. Arrange for flags added by the "release type" setting in CMake to be shown
 1764:     in the configuration summary.
 1765: 
 1766: 
 1767: Version 7.8 05-Sep-08
 1768: ---------------------
 1769: 
 1770: 1.  Replaced UCP searching code with optimized version as implemented for Ad
 1771:     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
 1772:     stage table and inline lookup instead of a function, giving speed ups of 2
 1773:     to 5 times on some simple patterns that I tested. Permission was given to
 1774:     distribute the MultiStage2.py script that generates the tables (it's not in
 1775:     the tarball, but is in the Subversion repository).
 1776: 
 1777: 2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
 1778:     scripts.
 1779: 
 1780: 3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
 1781:     a group with a zero qualifier. The result of the study could be incorrect,
 1782:     or the function might crash, depending on the pattern.
 1783: 
 1784: 4.  Caseless matching was not working for non-ASCII characters in back
 1785:     references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
 1786:     It now works when Unicode Property Support is available.
 1787: 
 1788: 5.  In pcretest, an escape such as \x{de} in the data was always generating
 1789:     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
 1790:     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
 1791:     truncation.
 1792: 
 1793: 6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
 1794: 
 1795: 7.  Added two (int) casts to pcregrep when printing the difference of two
 1796:     pointers, in case they are 64-bit values.
 1797: 
 1798: 8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
 1799:     test 2 if it fails.
 1800: 
 1801: 9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
 1802:     and a #define of that name to empty if it is not externally set. This is to
 1803:     allow users of MSVC to set it if necessary.
 1804: 
 1805: 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
 1806:     the convenience functions in the pcre_get.c source file.
 1807: 
 1808: 11. An option change at the start of a pattern that had top-level alternatives
 1809:     could cause overwriting and/or a crash. This command provoked a crash in
 1810:     some environments:
 1811: 
 1812:       printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
 1813: 
 1814:     This potential security problem was recorded as CVE-2008-2371.
 1815: 
 1816: 12. For a pattern where the match had to start at the beginning or immediately
 1817:     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
 1818:     pcre_dfa_exec() could read past the end of the passed subject if there was
 1819:     no match. To help with detecting such bugs (e.g. with valgrind), I modified
 1820:     pcretest so that it places the subject at the end of its malloc-ed buffer.
 1821: 
 1822: 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
 1823:     exec() might read past the end of the data buffer in UTF-8 mode.
 1824: 
 1825: 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
 1826:     the data contained the byte 0x85 as part of a UTF-8 character within its
 1827:     first line. This applied both to normal and DFA matching.
 1828: 
 1829: 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
 1830:     /^[^d]*?$/8 failed to match "abc".
 1831: 
 1832: 16. Added a missing copyright notice to pcrecpp_internal.h.
 1833: 
 1834: 17. Make it more clear in the documentation that values returned from
 1835:     pcre_exec() in ovector are byte offsets, not character counts.
 1836: 
 1837: 18. Tidied a few places to stop certain compilers from issuing warnings.
 1838: 
 1839: 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
 1840:     supplied by Stefan Weber. I made a further small update for 7.8 because
 1841:     there is a change of source arrangements: the pcre_searchfuncs.c module is
 1842:     replaced by pcre_ucd.c.
 1843: 
 1844: 
 1845: Version 7.7 07-May-08
 1846: ---------------------
 1847: 
 1848: 1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
 1849:     a string to a long long, pretend we don't even have a long long." This is
 1850:     done by checking for the strtoq, strtoll, and _strtoi64 functions.
 1851: 
 1852: 2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
 1853:     pre-7.6 versions, which defined a global no_arg variable instead of putting
 1854:     it in the RE class. (See also #8 below.)
 1855: 
 1856: 3.  Remove a line of dead code, identified by coverity and reported by Nuno
 1857:     Lopes.
 1858: 
 1859: 4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
 1860: 
 1861:     (1) The include/exclude patterns were being applied to the whole pathnames
 1862:         of files, instead of just to the final components.
 1863: 
 1864:     (2) If there was more than one level of directory, the subdirectories were
 1865:         skipped unless they satisfied the include/exclude conditions. This is
 1866:         inconsistent with GNU grep (and could even be seen as contrary to the
 1867:         pcregrep specification - which I improved to make it absolutely clear).
 1868:         The action now is always to scan all levels of directory, and just
 1869:         apply the include/exclude patterns to regular files.
 1870: 
 1871: 5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
 1872:     --exclude_dir in the tests to avoid scanning .svn directories.
 1873: 
 1874: 6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
 1875:     NUL character as backslash + 0 rather than backslash + NUL, because PCRE
 1876:     doesn't support NULs in patterns.
 1877: 
 1878: 7.  Added some missing "const"s to declarations of static tables in
 1879:     pcre_compile.c and pcre_dfa_exec.c.
 1880: 
 1881: 8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
 1882:     caused by fix #2  above. (Subsequently also a second patch to fix the
 1883:     first patch. And a third patch - this was a messy problem.)
 1884: 
 1885: 9.  Applied Craig's patch to remove the use of push_back().
 1886: 
 1887: 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
 1888:     matching function regexec().
 1889: 
 1890: 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
 1891:     which, however, unlike Perl's \g{...}, are subroutine calls, not back
 1892:     references. PCRE supports relative numbers with this syntax (I don't think
 1893:     Oniguruma does).
 1894: 
 1895: 12. Previously, a group with a zero repeat such as (...){0} was completely
 1896:     omitted from the compiled regex. However, this means that if the group
 1897:     was called as a subroutine from elsewhere in the pattern, things went wrong
 1898:     (an internal error was given). Such groups are now left in the compiled
 1899:     pattern, with a new opcode that causes them to be skipped at execution
 1900:     time.
 1901: 
 1902: 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
 1903:     to the way PCRE behaves:
 1904: 
 1905:     (a) A lone ] character is dis-allowed (Perl treats it as data).
 1906: 
 1907:     (b) A back reference to an unmatched subpattern matches an empty string
 1908:         (Perl fails the current match path).
 1909: 
 1910:     (c) A data ] in a character class must be notated as \] because if the
 1911:         first data character in a class is ], it defines an empty class. (In
 1912:         Perl it is not possible to have an empty class.) The empty class []
 1913:         never matches; it forces failure and is equivalent to (*FAIL) or (?!).
 1914:         The negative empty class [^] matches any one character, independently
 1915:         of the DOTALL setting.
 1916: 
 1917: 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
 1918:     non-existent subpattern following a character class starting with ']' and
 1919:     containing () gave an internal compiling error instead of "reference to
 1920:     non-existent subpattern". Fortunately, when the pattern did exist, the
 1921:     compiled code was correct. (When scanning forwards to check for the
 1922:     existence of the subpattern, it was treating the data ']' as terminating
 1923:     the class, so got the count wrong. When actually compiling, the reference
 1924:     was subsequently set up correctly.)
 1925: 
 1926: 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
 1927:     it was being rejected as not supported by pcre_dfa_exec(), even though
 1928:     other assertions are supported. I have made pcre_dfa_exec() support
 1929:     (*FAIL).
 1930: 
 1931: 16. The implementation of 13c above involved the invention of a new opcode,
 1932:     OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
 1933:     cannot be changed at match time, I realized I could make a small
 1934:     improvement to matching performance by compiling OP_ALLANY instead of
 1935:     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
 1936:     on the OP_ANY path.
 1937: 
 1938: 17. Compiling pcretest on Windows with readline support failed without the
 1939:     following two fixes: (1) Make the unistd.h include conditional on
 1940:     HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
 1941: 
 1942: 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
 1943:     ncurses library to be included for pcretest when ReadLine support is
 1944:     requested, but also to allow for it to be overridden. This patch came from
 1945:     Daniel Bergström.
 1946: 
 1947: 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
 1948:     as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
 1949:     any errors with the current Unicode tables. Thanks to Peter Kankowski for
 1950:     spotting this.
 1951: 
 1952: 
 1953: Version 7.6 28-Jan-08
 1954: ---------------------
 1955: 
 1956: 1.  A character class containing a very large number of characters with
 1957:     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
 1958:     overflow.
 1959: 
 1960: 2.  Patch to cut out the "long long" test in pcrecpp_unittest when
 1961:     HAVE_LONG_LONG is not defined.
 1962: 
 1963: 3.  Applied Christian Ehrlicher's patch to update the CMake build files to
 1964:     bring them up to date and include new features. This patch includes:
 1965: 
 1966:     - Fixed PH's badly added libz and libbz2 support.
 1967:     - Fixed a problem with static linking.
 1968:     - Added pcredemo. [But later removed - see 7 below.]
 1969:     - Fixed dftables problem and added an option.
 1970:     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
 1971:         HAVE_LONG_LONG.
 1972:     - Added readline support for pcretest.
 1973:     - Added an listing of the option settings after cmake has run.
 1974: 
 1975: 4.  A user submitted a patch to Makefile that makes it easy to create
 1976:     "pcre.dll" under mingw when using Configure/Make. I added stuff to
 1977:     Makefile.am that cause it to include this special target, without
 1978:     affecting anything else. Note that the same mingw target plus all
 1979:     the other distribution libraries and programs are now supported
 1980:     when configuring with CMake (see 6 below) instead of with
 1981:     Configure/Make.
 1982: 
 1983: 5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
 1984:     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
 1985:     exported in the Windows port". It has not yet been confirmed that the patch
 1986:     solves the problem, but it does no harm.
 1987: 
 1988: 6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
 1989:     NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
 1990:     with CMake, and also correct the comment about stack recursion.
 1991: 
 1992: 7.  Remove the automatic building of pcredemo from the ./configure system and
 1993:     from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
 1994:     of a program that users should build themselves after PCRE is installed, so
 1995:     building it automatically is not really right. What is more, it gave
 1996:     trouble in some build environments.
 1997: 
 1998: 8.  Further tidies to CMakeLists.txt from Sheri and Christian.
 1999: 
 2000: 
 2001: Version 7.5 10-Jan-08
 2002: ---------------------
 2003: 
 2004: 1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
 2005:     values in parens when parsing an RE using the C++ wrapper."
 2006: 
 2007: 2.  Negative specials like \S did not work in character classes in UTF-8 mode.
 2008:     Characters greater than 255 were excluded from the class instead of being
 2009:     included.
 2010: 
 2011: 3.  The same bug as (2) above applied to negated POSIX classes such as
 2012:     [:^space:].
 2013: 
 2014: 4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
 2015:     defined or documented. It seems to have been a typo for PCRE_STATIC, so
 2016:     I have changed it.
 2017: 
 2018: 5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
 2019:     first named subpattern) and a construct such as (?&a) would reference the
 2020:     first named subpattern whose name started with "a" (in other words, the
 2021:     length check was missing). Both these problems are fixed. "Subpattern name
 2022:     expected" is now given for (?&) (a zero-length name), and this patch also
 2023:     makes it give the same error for \k'' (previously it complained that that
 2024:     was a reference to a non-existent subpattern).
 2025: 
 2026: 6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
 2027:     this is right because (?- can be followed by option settings as well as by
 2028:     digits. I have, however, made the messages clearer.
 2029: 
 2030: 7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
 2031:     than the number used in the conditional) now cause a compile-time error.
 2032:     This is actually not compatible with Perl, which accepts such patterns, but
 2033:     treats the conditional as always being FALSE (as PCRE used to), but it
 2034:     seems to me that giving a diagnostic is better.
 2035: 
 2036: 8.  Change "alphameric" to the more common word "alphanumeric" in comments
 2037:     and messages.
 2038: 
 2039: 9.  Fix two occurrences of "backslash" in comments that should have been
 2040:     "backspace".
 2041: 
 2042: 10. Remove two redundant lines of code that can never be obeyed (their function
 2043:     was moved elsewhere).
 2044: 
 2045: 11. The program that makes PCRE's Unicode character property table had a bug
 2046:     which caused it to generate incorrect table entries for sequences of
 2047:     characters that have the same character type, but are in different scripts.
 2048:     It amalgamated them into a single range, with the script of the first of
 2049:     them. In other words, some characters were in the wrong script. There were
 2050:     thirteen such cases, affecting characters in the following ranges:
 2051: 
 2052:       U+002b0 - U+002c1
 2053:       U+0060c - U+0060d
 2054:       U+0061e - U+00612
 2055:       U+0064b - U+0065e
 2056:       U+0074d - U+0076d
 2057:       U+01800 - U+01805
 2058:       U+01d00 - U+01d77
 2059:       U+01d9b - U+01dbf
 2060:       U+0200b - U+0200f
 2061:       U+030fc - U+030fe
 2062:       U+03260 - U+0327f
 2063:       U+0fb46 - U+0fbb1
 2064:       U+10450 - U+1049d
 2065: 
 2066: 12. The -o option (show only the matching part of a line) for pcregrep was not
 2067:     compatible with GNU grep in that, if there was more than one match in a
 2068:     line, it showed only the first of them. It now behaves in the same way as
 2069:     GNU grep.
 2070: 
 2071: 13. If the -o and -v options were combined for pcregrep, it printed a blank
 2072:     line for every non-matching line. GNU grep prints nothing, and pcregrep now
 2073:     does the same. The return code can be used to tell if there were any
 2074:     non-matching lines.
 2075: 
 2076: 14. Added --file-offsets and --line-offsets to pcregrep.
 2077: 
 2078: 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
 2079:     infinitely looping recursion. The bug was that positive lookaheads were not
 2080:     being skipped when checking for a possible empty match (negative lookaheads
 2081:     and both kinds of lookbehind were skipped).
 2082: 
 2083: 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
 2084:     inclusion of <windows.h> to before rather than after the definition of
 2085:     INVALID_FILE_ATTRIBUTES (patch from David Byron).
 2086: 
 2087: 17. Specifying a possessive quantifier with a specific limit for a Unicode
 2088:     character property caused pcre_compile() to compile bad code, which led at
 2089:     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
 2090:     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
 2091:     caused the error; without that there was no problem.
 2092: 
 2093: 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
 2094: 
 2095: 19. Added --enable-pcretest-libreadline.
 2096: 
 2097: 20. In pcrecpp.cc, the variable 'count' was incremented twice in
 2098:     RE::GlobalReplace(). As a result, the number of replacements returned was
 2099:     double what it should be. I removed one of the increments, but Craig sent a
 2100:     later patch that removed the other one (the right fix) and added unit tests
 2101:     that check the return values (which was not done before).
 2102: 
 2103: 21. Several CMake things:
 2104: 
 2105:     (1) Arranged that, when cmake is used on Unix, the libraries end up with
 2106:         the names libpcre and libpcreposix, not just pcre and pcreposix.
 2107: 
 2108:     (2) The above change means that pcretest and pcregrep are now correctly
 2109:         linked with the newly-built libraries, not previously installed ones.
 2110: 
 2111:     (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
 2112: 
 2113: 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
 2114:     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
 2115:     UTF-8 newline character). The key issue is that the pattern starts .*;
 2116:     this means that the match must be either at the beginning, or after a
 2117:     newline. The bug was in the code for advancing after a failed match and
 2118:     checking that the new position followed a newline. It was not taking
 2119:     account of UTF-8 characters correctly.
 2120: 
 2121: 23. PCRE was behaving differently from Perl in the way it recognized POSIX
 2122:     character classes. PCRE was not treating the sequence [:...:] as a
 2123:     character class unless the ... were all letters. Perl, however, seems to
 2124:     allow any characters between [: and :], though of course it rejects as
 2125:     unknown any "names" that contain non-letters, because all the known class
 2126:     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
 2127:     for example, whereas PCRE did not - it did not recognize a POSIX character
 2128:     class. This seemed a bit dangerous, so the code has been changed to be
 2129:     closer to Perl. The behaviour is not identical to Perl, because PCRE will
 2130:     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
 2131:     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
 2132:     Perl does, and where it didn't before.
 2133: 
 2134: 24. Rewrite so as to remove the single use of %n from pcregrep because in some
 2135:     Windows environments %n is disabled by default.
 2136: 
 2137: 
 2138: Version 7.4 21-Sep-07
 2139: ---------------------
 2140: 
 2141: 1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
 2142:     means that a class such as [\s] counted as "explicit reference to CR or
 2143:     LF". That isn't really right - the whole point of the change was to try to
 2144:     help when there was an actual mention of one of the two characters. So now
 2145:     the change happens only if \r or \n (or a literal CR or LF) character is
 2146:     encountered.
 2147: 
 2148: 2.  The 32-bit options word was also used for 6 internal flags, but the numbers
 2149:     of both had grown to the point where there were only 3 bits left.
 2150:     Fortunately, there was spare space in the data structure, and so I have
 2151:     moved the internal flags into a new 16-bit field to free up more option
 2152:     bits.
 2153: 
 2154: 3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
 2155:     but did not set the internal JCHANGED flag - either of these is enough to
 2156:     control the way the "get" function works - but the PCRE_INFO_JCHANGED
 2157:     facility is supposed to tell if (?J) was ever used, so now (?J) at the
 2158:     start sets both bits.
 2159: 
 2160: 4.  Added options (at build time, compile time, exec time) to change \R from
 2161:     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
 2162: 
 2163: 5.  doc/pcresyntax.html was missing from the distribution.
 2164: 
 2165: 6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
 2166:     compatibility, even though it is no longer used.
 2167: 
 2168: 7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
 2169:     strtoull to pcrecpp.cc to select the available functions in WIN32 when the
 2170:     windows.h file is present (where different names are used). [This was
 2171:     reversed later after testing - see 16 below.]
 2172: 
 2173: 8.  Changed all #include <config.h> to #include "config.h". There were also
 2174:     some further <pcre.h> cases that I changed to "pcre.h".
 2175: 
 2176: 9.  When pcregrep was used with the --colour option, it missed the line ending
 2177:     sequence off the lines that it output.
 2178: 
 2179: 10. It was pointed out to me that arrays of string pointers cause lots of
 2180:     relocations when a shared library is dynamically loaded. A technique of
 2181:     using a single long string with a table of offsets can drastically reduce
 2182:     these. I have refactored PCRE in four places to do this. The result is
 2183:     dramatic:
 2184: 
 2185:       Originally:                          290
 2186:       After changing UCP table:            187
 2187:       After changing error message table:   43
 2188:       After changing table of "verbs"       36
 2189:       After changing table of Posix names   22
 2190: 
 2191:     Thanks to the folks working on Gregex for glib for this insight.
 2192: 
 2193: 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
 2194:     unicode-properties was also set.
 2195: 
 2196: 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
 2197: 
 2198: 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
 2199:     checked only for CRLF.
 2200: 
 2201: 14. Added casts to pcretest.c to avoid compiler warnings.
 2202: 
 2203: 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
 2204: 
 2205: 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
 2206:     and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
 2207:     entirely. This removes changes made in 7 above.
 2208: 
 2209: 17. The CMake files have been updated, and there is now more information about
 2210:     building with CMake in the NON-UNIX-USE document.
 2211: 
 2212: 
 2213: Version 7.3 28-Aug-07
 2214: ---------------------
 2215: 
 2216:  1. In the rejigging of the build system that eventually resulted in 7.1, the
 2217:     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
 2218:     brackets there is not right, since it causes compilers to look for an
 2219:     installed pcre.h, not the version that is in the source that is being
 2220:     compiled (which of course may be different). I have changed it back to:
 2221: 
 2222:       #include "pcre.h"
 2223: 
 2224:     I have a vague recollection that the change was concerned with compiling in
 2225:     different directories, but in the new build system, that is taken care of
 2226:     by the VPATH setting the Makefile.
 2227: 
 2228:  2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
 2229:     when the subject happened to end in the byte 0x85 (e.g. if the last
 2230:     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
 2231:     characters but of course it shouldn't be taken as a newline when it is part
 2232:     of another character. The bug was that, for an unlimited repeat of . in
 2233:     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
 2234:     characters when looking for a newline.
 2235: 
 2236:  3. A small performance improvement in the DOTALL UTF-8 mode .* case.
 2237: 
 2238:  4. Debugging: adjusted the names of opcodes for different kinds of parentheses
 2239:     in debug output.
 2240: 
 2241:  5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
 2242:     long printing in the pcrecpp unittest when running under MinGW.
 2243: 
 2244:  6. ESC_K was left out of the EBCDIC table.
 2245: 
 2246:  7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
 2247:     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
 2248:     limit also applies to "virtual nesting" when a pattern is recursive, and in
 2249:     this case 1000 isn't so big. I have been able to remove this limit at the
 2250:     expense of backing off one optimization in certain circumstances. Normally,
 2251:     when pcre_exec() would call its internal match() function recursively and
 2252:     immediately return the result unconditionally, it uses a "tail recursion"
 2253:     feature to save stack. However, when a subpattern that can match an empty
 2254:     string has an unlimited repetition quantifier, it no longer makes this
 2255:     optimization. That gives it a stack frame in which to save the data for
 2256:     checking that an empty string has been matched. Previously this was taken
 2257:     from the 1000-entry workspace that had been reserved. So now there is no
 2258:     explicit limit, but more stack is used.
 2259: 
 2260:  8. Applied Daniel's patches to solve problems with the import/export magic
 2261:     syntax that is required for Windows, and which was going wrong for the
 2262:     pcreposix and pcrecpp parts of the library. These were overlooked when this
 2263:     problem was solved for the main library.
 2264: 
 2265:  9. There were some crude static tests to avoid integer overflow when computing
 2266:     the size of patterns that contain repeated groups with explicit upper
 2267:     limits. As the maximum quantifier is 65535, the maximum group length was
 2268:     set at 30,000 so that the product of these two numbers did not overflow a
 2269:     32-bit integer. However, it turns out that people want to use groups that
 2270:     are longer than 30,000 bytes (though not repeat them that many times).
 2271:     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
 2272:     made it possible to implement the integer overflow checks in a much more
 2273:     dynamic way, which I have now done. The artificial limitation on group
 2274:     length has been removed - we now have only the limit on the total length of
 2275:     the compiled pattern, which depends on the LINK_SIZE setting.
 2276: 
 2277: 10. Fixed a bug in the documentation for get/copy named substring when
 2278:     duplicate names are permitted. If none of the named substrings are set, the
 2279:     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
 2280:     empty string.
 2281: 
 2282: 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
 2283:     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
 2284:     because the ] is interpreted as the first data character and the
 2285:     terminating ] is not found. PCRE has been made compatible with Perl in this
 2286:     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
 2287:     cause memory overwriting.
 2288: 
 2289: 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
 2290:     string has been matched (to stop an infinite loop). It was not recognizing
 2291:     a conditional subpattern that could match an empty string if that
 2292:     subpattern was within another subpattern. For example, it looped when
 2293:     trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
 2294:     condition was not nested. This bug has been fixed.
 2295: 
 2296: 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
 2297:     past the start of the subject in the presence of bytes with the top bit
 2298:     set, for example "\x8aBCD".
 2299: 
 2300: 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
 2301:     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
 2302: 
 2303: 14. Optimized (?!) to (*FAIL).
 2304: 
 2305: 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
 2306:     This restricts code points to be within the range 0 to 0x10FFFF, excluding
 2307:     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
 2308:     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
 2309:     does: it's just the validity check that is more restrictive.
 2310: 
 2311: 16. Inserted checks for integer overflows during escape sequence (backslash)
 2312:     processing, and also fixed erroneous offset values for syntax errors during
 2313:     backslash processing.
 2314: 
 2315: 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
 2316:     for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
 2317: 
 2318: 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
 2319:     caused an overrun.
 2320: 
 2321: 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
 2322:     something other than just ASCII characters) inside a group that had an
 2323:     unlimited repeat caused a loop at compile time (while checking to see
 2324:     whether the group could match an empty string).
 2325: 
 2326: 20. Debugging a pattern containing \p or \P could cause a crash. For example,
 2327:     [\P{Any}] did so. (Error in the code for printing property names.)
 2328: 
 2329: 21. An orphan \E inside a character class could cause a crash.
 2330: 
 2331: 22. A repeated capturing bracket such as (A)? could cause a wild memory
 2332:     reference during compilation.
 2333: 
 2334: 23. There are several functions in pcre_compile() that scan along a compiled
 2335:     expression for various reasons (e.g. to see if it's fixed length for look
 2336:     behind). There were bugs in these functions when a repeated \p or \P was
 2337:     present in the pattern. These operators have additional parameters compared
 2338:     with \d, etc, and these were not being taken into account when moving along
 2339:     the compiled data. Specifically:
 2340: 
 2341:     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
 2342:         length.
 2343: 
 2344:     (b) An item such as \pL+ within a repeated group could cause crashes or
 2345:         loops.
 2346: 
 2347:     (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
 2348:         "reference to non-existent subpattern" error.
 2349: 
 2350:     (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
 2351: 
 2352: 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
 2353:     characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
 2354: 
 2355: 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
 2356: 
 2357: 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
 2358:     character were causing crashes (broken optimization).
 2359: 
 2360: 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
 2361:     \p or \P) caused a compile-time loop.
 2362: 
 2363: 28. More problems have arisen in unanchored patterns when CRLF is a valid line
 2364:     break. For example, the unstudied pattern [\r\n]A does not match the string
 2365:     "\r\nA" because change 7.0/46 below moves the current point on by two
 2366:     characters after failing to match at the start. However, the pattern \nA
 2367:     *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
 2368:     the same is true. There doesn't seem any very clean way out of this, but
 2369:     what I have chosen to do makes the common cases work: PCRE now takes note
 2370:     of whether there can be an explicit match for \r or \n anywhere in the
 2371:     pattern, and if so, 7.0/46 no longer applies. As part of this change,
 2372:     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
 2373:     pattern has explicit CR or LF references.
 2374: 
 2375: 29. Added (*CR) etc for changing newline setting at start of pattern.
 2376: 
 2377: 
 2378: Version 7.2 19-Jun-07
 2379: ---------------------
 2380: 
 2381:  1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
 2382:     which is apparently normally available under Windows.
 2383: 
 2384:  2. Re-jig the pcregrep tests with different newline settings in an attempt
 2385:     to make them independent of the local environment's newline setting.
 2386: 
 2387:  3. Add code to configure.ac to remove -g from the CFLAGS default settings.
 2388: 
 2389:  4. Some of the "internals" tests were previously cut out when the link size
 2390:     was not 2, because the output contained actual offsets. The recent new
 2391:     "Z" feature of pcretest means that these can be cut out, making the tests
 2392:     usable with all link sizes.
 2393: 
 2394:  5. Implemented Stan Switzer's goto replacement for longjmp() when not using
 2395:     stack recursion. This gives a massive performance boost under BSD, but just
 2396:     a small improvement under Linux. However, it saves one field in the frame
 2397:     in all cases.
 2398: 
 2399:  6. Added more features from the forthcoming Perl 5.10:
 2400: 
 2401:     (a) (?-n) (where n is a string of digits) is a relative subroutine or
 2402:         recursion call. It refers to the nth most recently opened parentheses.
 2403: 
 2404:     (b) (?+n) is also a relative subroutine call; it refers to the nth next
 2405:         to be opened parentheses.
 2406: 
 2407:     (c) Conditions that refer to capturing parentheses can be specified
 2408:         relatively, for example, (?(-2)... or (?(+3)...
 2409: 
 2410:     (d) \K resets the start of the current match so that everything before
 2411:         is not part of it.
 2412: 
 2413:     (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
 2414: 
 2415:     (f) \g{name} is another synonym - part of Perl 5.10's unification of
 2416:         reference syntax.
 2417: 
 2418:     (g) (?| introduces a group in which the numbering of parentheses in each
 2419:         alternative starts with the same number.
 2420: 
 2421:     (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
 2422: 
 2423:  7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
 2424:     PCRE_INFO_JCHANGED.
 2425: 
 2426:  8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
 2427:     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
 2428:     for detecting groups that can match an empty string.
 2429: 
 2430:  9. A pattern with a very large number of alternatives (more than several
 2431:     hundred) was running out of internal workspace during the pre-compile
 2432:     phase, where pcre_compile() figures out how much memory will be needed. A
 2433:     bit of new cunning has reduced the workspace needed for groups with
 2434:     alternatives. The 1000-alternative test pattern now uses 12 bytes of
 2435:     workspace instead of running out of the 4096 that are available.
 2436: 
 2437: 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
 2438: 
 2439: 11. Applied patch from Google to remove an optimization that didn't quite work.
 2440:     The report of the bug said:
 2441: 
 2442:       pcrecpp::RE("a*").FullMatch("aaa") matches, while
 2443:       pcrecpp::RE("a*?").FullMatch("aaa") does not, and
 2444:       pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
 2445: 
 2446: 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
 2447:     it matched the wrong number of bytes.
 2448: 
 2449: 
 2450: Version 7.1 24-Apr-07
 2451: ---------------------
 2452: 
 2453:  1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
 2454:     that is more "standard", making use of automake and other Autotools. There
 2455:     is some re-arrangement of the files and adjustment of comments consequent
 2456:     on this.
 2457: 
 2458:  2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
 2459:     for recursive directory scanning broke on some systems because the files
 2460:     are not scanned in any specific order and on different systems the order
 2461:     was different. A call to "sort" has been inserted into RunGrepTest for the
 2462:     approprate test as a short-term fix. In the longer term there may be an
 2463:     alternative.
 2464: 
 2465:  3. I had an email from Eric Raymond about problems translating some of PCRE's
 2466:     man pages to HTML (despite the fact that I distribute HTML pages, some
 2467:     people do their own conversions for various reasons). The problems
 2468:     concerned the use of low-level troff macros .br and .in. I have therefore
 2469:     removed all such uses from the man pages (some were redundant, some could
 2470:     be replaced by .nf/.fi pairs). The 132html script that I use to generate
 2471:     HTML has been updated to handle .nf/.fi and to complain if it encounters
 2472:     .br or .in.
 2473: 
 2474:  4. Updated comments in configure.ac that get placed in config.h.in and also
 2475:     arranged for config.h to be included in the distribution, with the name
 2476:     config.h.generic, for the benefit of those who have to compile without
 2477:     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
 2478: 
 2479:  5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
 2480:     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
 2481:     makevp.bat for the current PCRE, using the additional files
 2482:     makevp_c.txt, makevp_l.txt, and pcregexp.pas.
 2483: 
 2484:  6. A Windows user reported a minor discrepancy with test 2, which turned out
 2485:     to be caused by a trailing space on an input line that had got lost in his
 2486:     copy. The trailing space was an accident, so I've just removed it.
 2487: 
 2488:  7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
 2489:     that is needed.
 2490: 
 2491:  8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
 2492:     as "const" (a) because they are and (b) because it helps the PHP
 2493:     maintainers who have recently made a script to detect big data structures
 2494:     in the php code that should be moved to the .rodata section. I remembered
 2495:     to update Builducptable as well, so it won't revert if ucptable.h is ever
 2496:     re-created.
 2497: 
 2498:  9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
 2499:     pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
 2500:     order to be able to cut out the UTF-8 tables in the latter when UTF-8
 2501:     support is not required. This saves 1.5-2K of code, which is important in
 2502:     some applications.
 2503: 
 2504:     Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
 2505:     so as not to refer to the tables, even though these functions will never be
 2506:     called when UTF-8 support is disabled. Otherwise there are problems with a
 2507:     shared library.
 2508: 
 2509: 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
 2510: 
 2511:     (a) It was defining its arguments as char * instead of void *.
 2512: 
 2513:     (b) It was assuming that all moves were upwards in memory; this was true
 2514:         a long time ago when I wrote it, but is no longer the case.
 2515: 
 2516:     The emulated memove() is provided for those environments that have neither
 2517:     memmove() nor bcopy(). I didn't think anyone used it these days, but that
 2518:     is clearly not the case, as these two bugs were recently reported.
 2519: 
 2520: 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
 2521:     and Detrail to create the HTML documentation, the .txt form of the man
 2522:     pages, and it removes trailing spaces from listed files. It also creates
 2523:     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
 2524:     case, it wraps all the #defines with #ifndefs. This script should be run
 2525:     before "make dist".
 2526: 
 2527: 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
 2528:     with Unicode property support.
 2529: 
 2530:     (a) For a maximizing quantifier, if the two different cases of the
 2531:         character were of different lengths in their UTF-8 codings (there are
 2532:         some cases like this - I found 11), and the matching function had to
 2533:         back up over a mixture of the two cases, it incorrectly assumed they
 2534:         were both the same length.
 2535: 
 2536:     (b) When PCRE was configured to use the heap rather than the stack for
 2537:         recursion during matching, it was not correctly preserving the data for
 2538:         the other case of a UTF-8 character when checking ahead for a match
 2539:         while processing a minimizing repeat. If the check also involved
 2540:         matching a wide character, but failed, corruption could cause an
 2541:         erroneous result when trying to check for a repeat of the original
 2542:         character.
 2543: 
 2544: 13. Some tidying changes to the testing mechanism:
 2545: 
 2546:     (a) The RunTest script now detects the internal link size and whether there
 2547:         is UTF-8 and UCP support by running ./pcretest -C instead of relying on
 2548:         values substituted by "configure". (The RunGrepTest script already did
 2549:         this for UTF-8.) The configure.ac script no longer substitutes the
 2550:         relevant variables.
 2551: 
 2552:     (b) The debugging options /B and /D in pcretest show the compiled bytecode
 2553:         with length and offset values. This means that the output is different
 2554:         for different internal link sizes. Test 2 is skipped for link sizes
 2555:         other than 2 because of this, bypassing the problem. Unfortunately,
 2556:         there was also a test in test 3 (the locale tests) that used /B and
 2557:         failed for link sizes other than 2. Rather than cut the whole test out,
 2558:         I have added a new /Z option to pcretest that replaces the length and
 2559:         offset values with spaces. This is now used to make test 3 independent
 2560:         of link size. (Test 2 will be tidied up later.)
 2561: 
 2562: 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
 2563:     segmentation fault instead of returning the appropriate error message.
 2564: 
 2565: 15. In multiline mode when the newline sequence was set to "any", the pattern
 2566:     ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
 2567:     This doesn't seem right; it now treats the CRLF combination as the line
 2568:     ending, and so does not match in that case. It's only a pattern such as ^$
 2569:     that would hit this one: something like ^ABC$ would have failed after \r
 2570:     and then tried again after \r\n.
 2571: 
 2572: 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
 2573:     in an attempt to make files that differ only in their line terminators
 2574:     compare equal. This works on Linux.
 2575: 
 2576: 17. Under certain error circumstances pcregrep might try to free random memory
 2577:     as it exited. This is now fixed, thanks to valgrind.
 2578: 
 2579: 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
 2580:     "abc\r\n\r\n", it found an unwanted second match after the second \r. This
 2581:     was because its rules for how to advance for /g after matching an empty
 2582:     string at the end of a line did not allow for this case. They now check for
 2583:     it specially.
 2584: 
 2585: 20. pcretest is supposed to handle patterns and data of any length, by
 2586:     extending its buffers when necessary. It was getting this wrong when the
 2587:     buffer for a data line had to be extended.
 2588: 
 2589: 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
 2590:     CRLF as a newline sequence.
 2591: 
 2592: 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
 2593:     out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
 2594:     I have nevertheless tidied it up.
 2595: 
 2596: 23. Added some casts to kill warnings from HP-UX ia64 compiler.
 2597: 
 2598: 24. Added a man page for pcre-config.
 2599: 
 2600: 
 2601: Version 7.0 19-Dec-06
 2602: ---------------------
 2603: 
 2604:  1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
 2605:     moving to gcc 4.1.1.
 2606: 
 2607:  2. The -S option for pcretest uses setrlimit(); I had omitted to #include
 2608:     sys/time.h, which is documented as needed for this function. It doesn't
 2609:     seem to matter on Linux, but it showed up on some releases of OS X.
 2610: 
 2611:  3. It seems that there are systems where bytes whose values are greater than
 2612:     127 match isprint() in the "C" locale. The "C" locale should be the
 2613:     default when a C program starts up. In most systems, only ASCII printing
 2614:     characters match isprint(). This difference caused the output from pcretest
 2615:     to vary, making some of the tests fail. I have changed pcretest so that:
 2616: 
 2617:     (a) When it is outputting text in the compiled version of a pattern, bytes
 2618:         other than 32-126 are always shown as hex escapes.
 2619: 
 2620:     (b) When it is outputting text that is a matched part of a subject string,
 2621:         it does the same, unless a different locale has been set for the match
 2622:         (using the /L modifier). In this case, it uses isprint() to decide.
 2623: 
 2624:  4. Fixed a major bug that caused incorrect computation of the amount of memory
 2625:     required for a compiled pattern when options that changed within the
 2626:     pattern affected the logic of the preliminary scan that determines the
 2627:     length. The relevant options are -x, and -i in UTF-8 mode. The result was
 2628:     that the computed length was too small. The symptoms of this bug were
 2629:     either the PCRE error "internal error: code overflow" from pcre_compile(),
 2630:     or a glibc crash with a message such as "pcretest: free(): invalid next
 2631:     size (fast)". Examples of patterns that provoked this bug (shown in
 2632:     pcretest format) are:
 2633: 
 2634:       /(?-x: )/x
 2635:       /(?x)(?-x: \s*#\s*)/
 2636:       /((?i)[\x{c0}])/8
 2637:       /(?i:[\x{c0}])/8
 2638: 
 2639:     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
 2640:     is now done differently.
 2641: 
 2642:  5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
 2643:     wrapper classes; (b) implement a new function in the C++ scanner that is
 2644:     more efficient than the old way of doing things because it avoids levels of
 2645:     recursion in the regex matching; (c) add a paragraph to the documentation
 2646:     for the FullMatch() function.
 2647: 
 2648:  6. The escape sequence \n was being treated as whatever was defined as
 2649:     "newline". Not only was this contrary to the documentation, which states
 2650:     that \n is character 10 (hex 0A), but it also went horribly wrong when
 2651:     "newline" was defined as CRLF. This has been fixed.
 2652: 
 2653:  7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
 2654:     was being set to -1 for the "end of line" case (supposedly a value that no
 2655:     character can have). Though this value is never used (the check for end of
 2656:     line is "zero bytes in current character"), it caused compiler complaints.
 2657:     I've changed it to 0xffffffff.
 2658: 
 2659:  8. In pcre_version.c, the version string was being built by a sequence of
 2660:     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
 2661:     string (as it is for production releases) called a macro with an empty
 2662:     argument. The C standard says the result of this is undefined. The gcc
 2663:     compiler treats it as an empty string (which was what was wanted) but it is
 2664:     reported that Visual C gives an error. The source has been hacked around to
 2665:     avoid this problem.
 2666: 
 2667:  9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
 2668:     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
 2669:     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
 2670:     of them did).
 2671: 
 2672: 10. Originally, pcretest opened its input and output without "b"; then I was
 2673:     told that "b" was needed in some environments, so it was added for release
 2674:     5.0 to both the input and output. (It makes no difference on Unix-like
 2675:     systems.) Later I was told that it is wrong for the input on Windows. I've
 2676:     now abstracted the modes into two macros, to make it easier to fiddle with
 2677:     them, and removed "b" from the input mode under Windows.
 2678: 
 2679: 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
 2680: 
 2681: 12. Added -help and --help to pcretest as an official way of being reminded
 2682:     of the options.
 2683: 
 2684: 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
 2685:     and pcrecpp.cc because they annoy compilers at high warning levels.
 2686: 
 2687: 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
 2688: 
 2689: 15. Fixed an occurrence of == in configure.ac that should have been = (shell
 2690:     scripts are not C programs :-) and which was not noticed because it works
 2691:     on Linux.
 2692: 
 2693: 16. pcretest is supposed to handle any length of pattern and data line (as one
 2694:     line or as a continued sequence of lines) by extending its input buffer if
 2695:     necessary. This feature was broken for very long pattern lines, leading to
 2696:     a string of junk being passed to pcre_compile() if the pattern was longer
 2697:     than about 50K.
 2698: 
 2699: 17. I have done a major re-factoring of the way pcre_compile() computes the
 2700:     amount of memory needed for a compiled pattern. Previously, there was code
 2701:     that made a preliminary scan of the pattern in order to do this. That was
 2702:     OK when PCRE was new, but as the facilities have expanded, it has become
 2703:     harder and harder to keep it in step with the real compile phase, and there
 2704:     have been a number of bugs (see for example, 4 above). I have now found a
 2705:     cunning way of running the real compile function in a "fake" mode that
 2706:     enables it to compute how much memory it would need, while actually only
 2707:     ever using a few hundred bytes of working memory and without too many
 2708:     tests of the mode. This should make future maintenance and development
 2709:     easier. A side effect of this work is that the limit of 200 on the nesting
 2710:     depth of parentheses has been removed (though this was never a serious
 2711:     limitation, I suspect). However, there is a downside: pcre_compile() now
 2712:     runs more slowly than before (30% or more, depending on the pattern). I
 2713:     hope this isn't a big issue. There is no effect on runtime performance.
 2714: 
 2715: 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
 2716:     newline (only possible for the last line of a file) and it was a
 2717:     pattern that set a locale (followed by /Lsomething), pcretest crashed.
 2718: 
 2719: 19. Added additional timing features to pcretest. (1) The -tm option now times
 2720:     matching only, not compiling. (2) Both -t and -tm can be followed, as a
 2721:     separate command line item, by a number that specifies the number of
 2722:     repeats to use when timing. The default is 50000; this gives better
 2723:     precision, but takes uncomfortably long for very large patterns.
 2724: 
 2725: 20. Extended pcre_study() to be more clever in cases where a branch of a
 2726:     subpattern has no definite first character. For example, (a*|b*)[cd] would
 2727:     previously give no result from pcre_study(). Now it recognizes that the
 2728:     first character must be a, b, c, or d.
 2729: 
 2730: 21. There was an incorrect error "recursive call could loop indefinitely" if
 2731:     a subpattern (or the entire pattern) that was being tested for matching an
 2732:     empty string contained only one non-empty item after a nested subpattern.
 2733:     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
 2734:     incorrectly, because the \d was being skipped in the check.
 2735: 
 2736: 22. The pcretest program now has a new pattern option /B and a command line
 2737:     option -b, which is equivalent to adding /B to every pattern. This causes
 2738:     it to show the compiled bytecode, without the additional information that
 2739:     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
 2740:     is the same as /B/I).
 2741: 
 2742: 23. A new optimization is now able automatically to treat some sequences such
 2743:     as a*b as a*+b. More specifically, if something simple (such as a character
 2744:     or a simple class like \d) has an unlimited quantifier, and is followed by
 2745:     something that cannot possibly match the quantified thing, the quantifier
 2746:     is automatically "possessified".
 2747: 
 2748: 24. A recursive reference to a subpattern whose number was greater than 39
 2749:     went wrong under certain circumstances in UTF-8 mode. This bug could also
 2750:     have affected the operation of pcre_study().
 2751: 
 2752: 25. Realized that a little bit of performance could be had by replacing
 2753:     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
 2754: 
 2755: 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
 2756: 
 2757: 27. Possessive quantifiers such as a++ were previously implemented by turning
 2758:     them into atomic groups such as ($>a+). Now they have their own opcodes,
 2759:     which improves performance. This includes the automatically created ones
 2760:     from 23 above.
 2761: 
 2762: 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
 2763:     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
 2764:     the first matched character to be a colon. This applied both to named and
 2765:     numbered groups.
 2766: 
 2767: 29. The ucpinternal.h header file was missing its idempotency #ifdef.
 2768: 
 2769: 30. I was sent a "project" file called libpcre.a.dev which I understand makes
 2770:     building PCRE on Windows easier, so I have included it in the distribution.
 2771: 
 2772: 31. There is now a check in pcretest against a ridiculously large number being
 2773:     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
 2774:     loop, the loop is abandoned.
 2775: 
 2776: 32. Forward references to subpatterns in conditions such as (?(2)...) where
 2777:     subpattern 2 is defined later cause pcre_compile() to search forwards in
 2778:     the pattern for the relevant set of parentheses. This search went wrong
 2779:     when there were unescaped parentheses in a character class, parentheses
 2780:     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
 2781: 
 2782: 33. "Subroutine" calls and backreferences were previously restricted to
 2783:     referencing subpatterns earlier in the regex. This restriction has now
 2784:     been removed.
 2785: 
 2786: 34. Added a number of extra features that are going to be in Perl 5.10. On the
 2787:     whole, these are just syntactic alternatives for features that PCRE had
 2788:     previously implemented using the Python syntax or my own invention. The
 2789:     other formats are all retained for compatibility.
 2790: 
 2791:     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
 2792:         as (?P<name>...). The new forms, as well as being in Perl 5.10, are
 2793:         also .NET compatible.
 2794: 
 2795:     (b) A recursion or subroutine call to a named group can now be defined as
 2796:         (?&name) as well as (?P>name).
 2797: 
 2798:     (c) A backreference to a named group can now be defined as \k<name> or
 2799:         \k'name' as well as (?P=name). The new forms, as well as being in Perl
 2800:         5.10, are also .NET compatible.
 2801: 
 2802:     (d) A conditional reference to a named group can now use the syntax
 2803:         (?(<name>) or (?('name') as well as (?(name).
 2804: 
 2805:     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
 2806:         groups (named and numbered) that are never evaluated inline, but can be
 2807:         called as "subroutines" from elsewhere. In effect, the DEFINE condition
 2808:         is always false. There may be only one alternative in such a group.
 2809: 
 2810:     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
 2811:         as the simple (?(R). The condition is true only if the most recent
 2812:         recursion is that of the given number or name. It does not search out
 2813:         through the entire recursion stack.
 2814: 
 2815:     (g) The escape \gN or \g{N} has been added, where N is a positive or
 2816:         negative number, specifying an absolute or relative reference.
 2817: 
 2818: 35. Tidied to get rid of some further signed/unsigned compiler warnings and
 2819:     some "unreachable code" warnings.
 2820: 
 2821: 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
 2822:     things, this adds five new scripts.
 2823: 
 2824: 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
 2825:     There were also incompatibilities regarding the handling of \Q..\E inside
 2826:     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
 2827:     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
 2828: 
 2829: 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
 2830:     matches an empty string, and forcibly breaks the loop. There were bugs in
 2831:     this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
 2832:     against  aaaa  the result was just "a" rather than "aaaa", for example. Two
 2833:     separate and independent bugs (that affected different cases) have been
 2834:     fixed.
 2835: 
 2836: 39. Refactored the code to abolish the use of different opcodes for small
 2837:     capturing bracket numbers. This is a tidy that I avoided doing when I
 2838:     removed the limit on the number of capturing brackets for 3.5 back in 2001.
 2839:     The new approach is not only tidier, it makes it possible to reduce the
 2840:     memory needed to fix the previous bug (38).
 2841: 
 2842: 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
 2843:     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
 2844:     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
 2845:     mode.
 2846: 
 2847: 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
 2848:     report.
 2849: 
 2850: 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
 2851:     copy construction and assignment in the C++ wrapper.
 2852: 
 2853: 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
 2854:     couple of bugs that could have given wrong results in the "--newline=crlf"
 2855:     case.
 2856: 
 2857: 44. Added a number of casts and did some reorganization of signed/unsigned int
 2858:     variables following suggestions from Dair Grant. Also renamed the variable
 2859:     "this" as "item" because it is a C++ keyword.
 2860: 
 2861: 45. Arranged for dftables to add
 2862: 
 2863:       #include "pcre_internal.h"
 2864: 
 2865:     to pcre_chartables.c because without it, gcc 4.x may remove the array
 2866:     definition from the final binary if PCRE is built into a static library and
 2867:     dead code stripping is activated.
 2868: 
 2869: 46. For an unanchored pattern, if a match attempt fails at the start of a
 2870:     newline sequence, and the newline setting is CRLF or ANY, and the next two
 2871:     characters are CRLF, advance by two characters instead of one.
 2872: 
 2873: 
 2874: Version 6.7 04-Jul-06
 2875: ---------------------
 2876: 
 2877:  1. In order to handle tests when input lines are enormously long, pcretest has
 2878:     been re-factored so that it automatically extends its buffers when
 2879:     necessary. The code is crude, but this _is_ just a test program. The
 2880:     default size has been increased from 32K to 50K.
 2881: 
 2882:  2. The code in pcre_study() was using the value of the re argument before
 2883:     testing it for NULL. (Of course, in any sensible call of the function, it
 2884:     won't be NULL.)
 2885: 
 2886:  3. The memmove() emulation function in pcre_internal.h, which is used on
 2887:     systems that lack both memmove() and bcopy() - that is, hardly ever -
 2888:     was missing a "static" storage class specifier.
 2889: 
 2890:  4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
 2891:     containing an extended class (one that cannot be represented by a bitmap
 2892:     because it contains high-valued characters or Unicode property items, e.g.
 2893:     [\pZ]). Almost always one would set UTF-8 mode when processing such a
 2894:     pattern, but PCRE should not loop if you do not (it no longer does).
 2895:     [Detail: two cases were found: (a) a repeated subpattern containing an
 2896:     extended class; (b) a recursive reference to a subpattern that followed a
 2897:     previous extended class. It wasn't skipping over the extended class
 2898:     correctly when UTF-8 mode was not set.]
 2899: 
 2900:  5. A negated single-character class was not being recognized as fixed-length
 2901:     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
 2902:     compile error "lookbehind assertion is not fixed length".
 2903: 
 2904:  6. The RunPerlTest auxiliary script was showing an unexpected difference
 2905:     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
 2906:     write a Perl script that can interpret lines of an input file either as
 2907:     byte characters or as UTF-8, which is what "perltest" was being required to
 2908:     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
 2909:     can't do is switch easily at run time between having the "use utf8;" pragma
 2910:     or not. In the end, I fudged it by using the RunPerlTest script to insert
 2911:     "use utf8;" explicitly for the UTF-8 tests.
 2912: 
 2913:  7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
 2914:     the end of the subject string, contrary to the documentation and to what
 2915:     Perl does. This was true of both matching functions. Now it matches only at
 2916:     the start of the subject and immediately after *internal* newlines.
 2917: 
 2918:  8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
 2919:     a pointer to an int instead of a pointer to an unsigned long int. This
 2920:     caused problems on 64-bit systems.
 2921: 
 2922:  9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
 2923:     instance of the 'standard' template library not being so standard".
 2924: 
 2925: 10. There was no check on the number of named subpatterns nor the maximum
 2926:     length of a subpattern name. The product of these values is used to compute
 2927:     the size of the memory block for a compiled pattern. By supplying a very
 2928:     long subpattern name and a large number of named subpatterns, the size
 2929:     computation could be caused to overflow. This is now prevented by limiting
 2930:     the length of names to 32 characters, and the number of named subpatterns
 2931:     to 10,000.
 2932: 
 2933: 11. Subpatterns that are repeated with specific counts have to be replicated in
 2934:     the compiled pattern. The size of memory for this was computed from the
 2935:     length of the subpattern and the repeat count. The latter is limited to
 2936:     65535, but there was no limit on the former, meaning that integer overflow
 2937:     could in principle occur. The compiled length of a repeated subpattern is
 2938:     now limited to 30,000 bytes in order to prevent this.
 2939: 
 2940: 12. Added the optional facility to have named substrings with the same name.
 2941: 
 2942: 13. Added the ability to use a named substring as a condition, using the
 2943:     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
 2944:     are numbers (not recommended). Forward references are permitted.
 2945: 
 2946: 14. Added forward references in named backreferences (if you see what I mean).
 2947: 
 2948: 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
 2949:     pattern could run off the end of the subject. For example, the pattern
 2950:     "(?s)(.{1,5})"8 did this with the subject "ab".
 2951: 
 2952: 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
 2953:     PCRE_CASELESS was set when matching characters that were quantified with ?
 2954:     or *.
 2955: 
 2956: 17. A character class other than a single negated character that had a minimum
 2957:     but no maximum quantifier - for example [ab]{6,} - was not handled
 2958:     correctly by pce_dfa_exec(). It would match only one character.
 2959: 
 2960: 18. A valid (though odd) pattern that looked like a POSIX character
 2961:     class but used an invalid character after [ (for example [[,abc,]]) caused
 2962:     pcre_compile() to give the error "Failed: internal error: code overflow" or
 2963:     in some cases to crash with a glibc free() error. This could even happen if
 2964:     the pattern terminated after [[ but there just happened to be a sequence of
 2965:     letters, a binary zero, and a closing ] in the memory that followed.
 2966: 
 2967: 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
 2968:     over the years. Originally (before any Unicode support), just the bottom 8
 2969:     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
 2970:     output from "man perlunicode" includes this:
 2971: 
 2972:       The regular expression compiler produces polymorphic opcodes.  That
 2973:       is, the pattern adapts to the data and automatically switches to
 2974:       the Unicode character scheme when presented with Unicode data--or
 2975:       instead uses a traditional byte scheme when presented with byte
 2976:       data.
 2977: 
 2978:     Sadly, a wide octal escape does not cause a switch, and in a string with
 2979:     no other multibyte characters, these octal escapes are treated as before.
 2980:     Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
 2981:     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
 2982:     Unicode string.
 2983: 
 2984:     I have not perpetrated such confusion in PCRE. Up till now, it took just
 2985:     the bottom 8 bits, as in old Perl. I have now made octal escapes with
 2986:     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
 2987:     translate to the appropriate multibyte character.
 2988: 
 2989: 29. Applied some refactoring to reduce the number of warnings from Microsoft
 2990:     and Borland compilers. This has included removing the fudge introduced
 2991:     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
 2992:     a warning about an unused variable.
 2993: 
 2994: 21. PCRE has not included VT (character 0x0b) in the set of whitespace
 2995:     characters since release 4.0, because Perl (from release 5.004) does not.
 2996:     [Or at least, is documented not to: some releases seem to be in conflict
 2997:     with the documentation.] However, when a pattern was studied with
 2998:     pcre_study() and all its branches started with \s, PCRE still included VT
 2999:     as a possible starting character. Of course, this did no harm; it just
 3000:     caused an unnecessary match attempt.
 3001: 
 3002: 22. Removed a now-redundant internal flag bit that recorded the fact that case
 3003:     dependency changed within the pattern. This was once needed for "required
 3004:     byte" processing, but is no longer used. This recovers a now-scarce options
 3005:     bit. Also moved the least significant internal flag bit to the most-
 3006:     significant bit of the word, which was not previously used (hangover from
 3007:     the days when it was an int rather than a uint) to free up another bit for
 3008:     the future.
 3009: 
 3010: 23. Added support for CRLF line endings as well as CR and LF. As well as the
 3011:     default being selectable at build time, it can now be changed at runtime
 3012:     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
 3013:     specify that it is scanning data with non-default line endings.
 3014: 
 3015: 24. Changed the definition of CXXLINK to make it agree with the definition of
 3016:     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
 3017: 
 3018: 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
 3019:     recursions. This makes a big different to stack usage for some patterns.
 3020: 
 3021: 26. If a subpattern containing a named recursion or subroutine reference such
 3022:     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
 3023:     the space required for the compiled pattern went wrong and gave too small a
 3024:     value. Depending on the environment, this could lead to "Failed: internal
 3025:     error: code overflow at offset 49" or "glibc detected double free or
 3026:     corruption" errors.
 3027: 
 3028: 27. Applied patches from Google (a) to support the new newline modes and (b) to
 3029:     advance over multibyte UTF-8 characters in GlobalReplace.
 3030: 
 3031: 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
 3032:     difference for some implementation of PCRE in some Windows version.
 3033: 
 3034: 29. Added some extra testing facilities to pcretest:
 3035: 
 3036:     \q<number>   in a data line sets the "match limit" value
 3037:     \Q<number>   in a data line sets the "match recursion limt" value
 3038:     -S <number>  sets the stack size, where <number> is in megabytes
 3039: 
 3040:     The -S option isn't available for Windows.
 3041: 
 3042: 
 3043: Version 6.6 06-Feb-06
 3044: ---------------------
 3045: 
 3046:  1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
 3047:     in pcreposix.h. I have copied the definition from pcre.h.
 3048: 
 3049:  2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
 3050:     because pcre.h is no longer a built file.
 3051: 
 3052:  3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
 3053:     not normally included in the compiled code.
 3054: 
 3055: 
 3056: Version 6.5 01-Feb-06
 3057: ---------------------
 3058: 
 3059:  1. When using the partial match feature with pcre_dfa_exec(), it was not
 3060:     anchoring the second and subsequent partial matches at the new starting
 3061:     point. This could lead to incorrect results. For example, with the pattern
 3062:     /1234/, partially matching against "123" and then "a4" gave a match.
 3063: 
 3064:  2. Changes to pcregrep:
 3065: 
 3066:     (a) All non-match returns from pcre_exec() were being treated as failures
 3067:         to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
 3068:         error message is output. Some extra information is given for the
 3069:         PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
 3070:         probably the only errors that are likely to be caused by users (by
 3071:         specifying a regex that has nested indefinite repeats, for instance).
 3072:         If there are more than 20 of these errors, pcregrep is abandoned.
 3073: 
 3074:     (b) A binary zero was treated as data while matching, but terminated the
 3075:         output line if it was written out. This has been fixed: binary zeroes
 3076:         are now no different to any other data bytes.
 3077: 
 3078:     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
 3079:         used to set a locale for matching. The --locale=xxxx long option has
 3080:         been added (no short equivalent) to specify a locale explicitly on the
 3081:         pcregrep command, overriding the environment variables.
 3082: 
 3083:     (d) When -B was used with -n, some line numbers in the output were one less
 3084:         than they should have been.
 3085: 
 3086:     (e) Added the -o (--only-matching) option.
 3087: 
 3088:     (f) If -A or -C was used with -c (count only), some lines of context were
 3089:         accidentally printed for the final match.
 3090: 
 3091:     (g) Added the -H (--with-filename) option.
 3092: 
 3093:     (h) The combination of options -rh failed to suppress file names for files
 3094:         that were found from directory arguments.
 3095: 
 3096:     (i) Added the -D (--devices) and -d (--directories) options.
 3097: 
 3098:     (j) Added the -F (--fixed-strings) option.
 3099: 
 3100:     (k) Allow "-" to be used as a file name for -f as well as for a data file.
 3101: 
 3102:     (l) Added the --colo(u)r option.
 3103: 
 3104:     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
 3105:         is not present by default.
 3106: 
 3107:  3. A nasty bug was discovered in the handling of recursive patterns, that is,
 3108:     items such as (?R) or (?1), when the recursion could match a number of
 3109:     alternatives. If it matched one of the alternatives, but subsequently,
 3110:     outside the recursion, there was a failure, the code tried to back up into
 3111:     the recursion. However, because of the way PCRE is implemented, this is not
 3112:     possible, and the result was an incorrect result from the match.
 3113: 
 3114:     In order to prevent this happening, the specification of recursion has
 3115:     been changed so that all such subpatterns are automatically treated as
 3116:     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
 3117: 
 3118:  4. I had overlooked the fact that, in some locales, there are characters for
 3119:     which isalpha() is true but neither isupper() nor islower() are true. In
 3120:     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
 3121:     and ordfeminine) are like this. This affected the treatment of \w and \W
 3122:     when they appeared in character classes, but not when they appeared outside
 3123:     a character class. The bit map for "word" characters is now created
 3124:     separately from the results of isalnum() instead of just taking it from the
 3125:     upper, lower, and digit maps. (Plus the underscore character, of course.)
 3126: 
 3127:  5. The above bug also affected the handling of POSIX character classes such as
 3128:     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
 3129:     permanent tables. Instead, the bit maps for such a class were previously
 3130:     created as the appropriate unions of the upper, lower, and digit bitmaps.
 3131:     Now they are created by subtraction from the [[:word:]] class, which has
 3132:     its own bitmap.
 3133: 
 3134:  6. The [[:blank:]] character class matches horizontal, but not vertical space.
 3135:     It is created by subtracting the vertical space characters (\x09, \x0a,
 3136:     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
 3137:     subtraction was done in the overall bitmap for a character class, meaning
 3138:     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
 3139:     be recognized. This bug has been fixed.
 3140: 
 3141:  7. Patches from the folks at Google:
 3142: 
 3143:       (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
 3144:       real life, but is still worth protecting against".
 3145: 
 3146:       (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
 3147:       regular expressions".
 3148: 
 3149:       (c) pcre_scanner.cc: avoid use of std::count() because not all systems
 3150:       have it.
 3151: 
 3152:       (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
 3153:       "configure" and the latter not, in order to fix a problem somebody had
 3154:       with compiling the Arg class on HP-UX.
 3155: 
 3156:       (e) Improve the error-handling of the C++ wrapper a little bit.
 3157: 
 3158:       (f) New tests for checking recursion limiting.
 3159: 
 3160:  8. The pcre_memmove() function, which is used only if the environment does not
 3161:     have a standard memmove() function (and is therefore rarely compiled),
 3162:     contained two bugs: (a) use of int instead of size_t, and (b) it was not
 3163:     returning a result (though PCRE never actually uses the result).
 3164: 
 3165:  9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
 3166:     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
 3167:     returned instead of calling malloc() with an overflowing number that would
 3168:     most likely cause subsequent chaos.
 3169: 
 3170: 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
 3171: 
 3172: 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
 3173:     with this option is matched, the nmatch and pmatch options of regexec() are
 3174:     ignored.
 3175: 
 3176: 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
 3177:     provided in case anyone wants to the the POSIX interface with UTF-8
 3178:     strings.
 3179: 
 3180: 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
 3181:     C++ linking (needed for some HP-UX environments).
 3182: 
 3183: 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
 3184:     (unused parameter) and in the pcre_printint() function (omitted "default"
 3185:     switch label when the default is to do nothing).
 3186: 
 3187: 15. Added some code to make it possible, when PCRE is compiled as a C++
 3188:     library, to replace subject pointers for pcre_exec() with a smart pointer
 3189:     class, thus making it possible to process discontinuous strings.
 3190: 
 3191: 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
 3192:     much the same function. They were added by different people who were trying
 3193:     to make PCRE easy to compile on non-Unix systems. It has been suggested
 3194:     that PCRE_EXPORT be abolished now that there is more automatic apparatus
 3195:     for compiling on Windows systems. I have therefore replaced it with
 3196:     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
 3197:     defaults to "extern" for C or "extern C" for C++, which works fine on
 3198:     Unix-like systems. It is now possible to override the value of PCRE_DATA_
 3199:     SCOPE with something explicit in config.h. In addition:
 3200: 
 3201:     (a) pcreposix.h still had just "extern" instead of either of these macros;
 3202:         I have replaced it with PCRE_DATA_SCOPE.
 3203: 
 3204:     (b) Functions such as _pcre_xclass(), which are internal to the library,
 3205:         but external in the C sense, all had PCRE_EXPORT in their definitions.
 3206:         This is apparently wrong for the Windows case, so I have removed it.
 3207:         (It makes no difference on Unix-like systems.)
 3208: 
 3209: 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
 3210:     of recursive calls to match(). This is different to MATCH_LIMIT because
 3211:     that limits the total number of calls to match(), not all of which increase
 3212:     the depth of recursion. Limiting the recursion depth limits the amount of
 3213:     stack (or heap if NO_RECURSE is set) that is used. The default can be set
 3214:     when PCRE is compiled, and changed at run time. A patch from Google adds
 3215:     this functionality to the C++ interface.
 3216: 
 3217: 18. Changes to the handling of Unicode character properties:
 3218: 
 3219:     (a) Updated the table to Unicode 4.1.0.
 3220: 
 3221:     (b) Recognize characters that are not in the table as "Cn" (undefined).
 3222: 
 3223:     (c) I revised the way the table is implemented to a much improved format
 3224:         which includes recognition of ranges. It now supports the ranges that
 3225:         are defined in UnicodeData.txt, and it also amalgamates other
 3226:         characters into ranges. This has reduced the number of entries in the
 3227:         table from around 16,000 to around 3,000, thus reducing its size
 3228:         considerably. I realized I did not need to use a tree structure after
 3229:         all - a binary chop search is just as efficient. Having reduced the
 3230:         number of entries, I extended their size from 6 bytes to 8 bytes to
 3231:         allow for more data.
 3232: 
 3233:     (d) Added support for Unicode script names via properties such as \p{Han}.
 3234: 
 3235: 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
 3236:     matching that character.
 3237: 
 3238: 20. When matching a repeated Unicode property with a minimum greater than zero,
 3239:     (for example \pL{2,}), PCRE could look past the end of the subject if it
 3240:     reached it while seeking the minimum number of characters. This could
 3241:     happen only if some of the characters were more than one byte long, because
 3242:     there is a check for at least the minimum number of bytes.
 3243: 
 3244: 21. Refactored the implementation of \p and \P so as to be more general, to
 3245:     allow for more different types of property in future. This has changed the
 3246:     compiled form incompatibly. Anybody with saved compiled patterns that use
 3247:     \p or \P will have to recompile them.
 3248: 
 3249: 22. Added "Any" and "L&" to the supported property types.
 3250: 
 3251: 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
 3252:     but give a compile time error if the value is greater than 0xff.
 3253: 
 3254: 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
 3255:     accidentally not being installed or uninstalled.
 3256: 
 3257: 25. The pcre.h file was built from pcre.h.in, but the only changes that were
 3258:     made were to insert the current release number. This seemed silly, because
 3259:     it made things harder for people building PCRE on systems that don't run
 3260:     "configure". I have turned pcre.h into a distributed file, no longer built
 3261:     by "configure", with the version identification directly included. There is
 3262:     no longer a pcre.h.in file.
 3263: 
 3264:     However, this change necessitated a change to the pcre-config script as
 3265:     well. It is built from pcre-config.in, and one of the substitutions was the
 3266:     release number. I have updated configure.ac so that ./configure now finds
 3267:     the release number by grepping pcre.h.
 3268: 
 3269: 26. Added the ability to run the tests under valgrind.
 3270: 
 3271: 
 3272: Version 6.4 05-Sep-05
 3273: ---------------------
 3274: 
 3275:  1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
 3276:     "--" to be printed when multiple files were scanned, even when none of the
 3277:     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
 3278:     consider it to be a bug, and have restored the previous behaviour.
 3279: 
 3280:  2. A couple of code tidies to get rid of compiler warnings.
 3281: 
 3282:  3. The pcretest program used to cheat by referring to symbols in the library
 3283:     whose names begin with _pcre_. These are internal symbols that are not
 3284:     really supposed to be visible externally, and in some environments it is
 3285:     possible to suppress them. The cheating is now confined to including
 3286:     certain files from the library's source, which is a bit cleaner.
 3287: 
 3288:  4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
 3289:     file's purpose clearer.
 3290: 
 3291:  5. Reorganized pcre_ucp_findchar().
 3292: 
 3293: 
 3294: Version 6.3 15-Aug-05
 3295: ---------------------
 3296: 
 3297:  1. The file libpcre.pc.in did not have general read permission in the tarball.
 3298: 
 3299:  2. There were some problems when building without C++ support:
 3300: 
 3301:     (a) If C++ support was not built, "make install" and "make test" still
 3302:         tried to test it.
 3303: 
 3304:     (b) There were problems when the value of CXX was explicitly set. Some
 3305:         changes have been made to try to fix these, and ...
 3306: 
 3307:     (c) --disable-cpp can now be used to explicitly disable C++ support.
 3308: 
 3309:     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
 3310:         backslash in a target when C++ was disabled. This confuses some
 3311:         versions of "make", apparently. Using an intermediate variable solves
 3312:         this. (Same for CPP_LOBJ.)
 3313: 
 3314:  3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
 3315:     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
 3316:     necessary on certain architectures.
 3317: 
 3318:  4. Added a setting of -export-symbols-regex to the link command to remove
 3319:     those symbols that are exported in the C sense, but actually are local
 3320:     within the library, and not documented. Their names all begin with
 3321:     "_pcre_". This is not a perfect job, because (a) we have to except some
 3322:     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
 3323:     available (and never for static libraries). I have made a note to try to
 3324:     find a way round (a) in the future.
 3325: 
 3326: 
 3327: Version 6.2 01-Aug-05
 3328: ---------------------
 3329: 
 3330:  1. There was no test for integer overflow of quantifier values. A construction
 3331:     such as {1111111111111111} would give undefined results. What is worse, if
 3332:     a minimum quantifier for a parenthesized subpattern overflowed and became
 3333:     negative, the calculation of the memory size went wrong. This could have
 3334:     led to memory overwriting.
 3335: 
 3336:  2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
 3337: 
 3338:  3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
 3339:     operating environments where this matters.
 3340: 
 3341:  4. Applied Giuseppe Maxia's patch to add additional features for controlling
 3342:     PCRE options from within the C++ wrapper.
 3343: 
 3344:  5. Named capturing subpatterns were not being correctly counted when a pattern
 3345:     was compiled. This caused two problems: (a) If there were more than 100
 3346:     such subpatterns, the calculation of the memory needed for the whole
 3347:     compiled pattern went wrong, leading to an overflow error. (b) Numerical
 3348:     back references of the form \12, where the number was greater than 9, were
 3349:     not recognized as back references, even though there were sufficient
 3350:     previous subpatterns.
 3351: 
 3352:  6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
 3353:     versions of gcc, e.g. 2.95.4.
 3354: 
 3355: 
 3356: Version 6.1 21-Jun-05
 3357: ---------------------
 3358: 
 3359:  1. There was one reference to the variable "posix" in pcretest.c that was not
 3360:     surrounded by "#if !defined NOPOSIX".
 3361: 
 3362:  2. Make it possible to compile pcretest without DFA support, UTF8 support, or
 3363:     the cross-check on the old pcre_info() function, for the benefit of the
 3364:     cut-down version of PCRE that is currently imported into Exim.
 3365: 
 3366:  3. A (silly) pattern starting with (?i)(?-i) caused an internal space
 3367:     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
 3368:     patterns that start (?i) but I don't think that matters. The use of (?i) is
 3369:     just an example; this all applies to the other options as well.
 3370: 
 3371:  4. Since libtool seems to echo the compile commands it is issuing, the output
 3372:     from "make" can be reduced a bit by putting "@" in front of each libtool
 3373:     compile command.
 3374: 
 3375:  5. Patch from the folks at Google for configure.in to be a bit more thorough
 3376:     in checking for a suitable C++ installation before trying to compile the
 3377:     C++ stuff. This should fix a reported problem when a compiler was present,
 3378:     but no suitable headers.
 3379: 
 3380:  6. The man pages all had just "PCRE" as their title. I have changed them to
 3381:     be the relevant file name. I have also arranged that these names are
 3382:     retained in the file doc/pcre.txt, which is a concatenation in text format
 3383:     of all the man pages except the little individual ones for each function.
 3384: 
 3385:  7. The NON-UNIX-USE file had not been updated for the different set of source
 3386:     files that come with release 6. I also added a few comments about the C++
 3387:     wrapper.
 3388: 
 3389: 
 3390: Version 6.0 07-Jun-05
 3391: ---------------------
 3392: 
 3393:  1. Some minor internal re-organization to help with my DFA experiments.
 3394: 
 3395:  2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
 3396:     didn't matter for the library itself when fully configured, but did matter
 3397:     when compiling without UCP support, or within Exim, where the ucp files are
 3398:     not imported.
 3399: 
 3400:  3. Refactoring of the library code to split up the various functions into
 3401:     different source modules. The addition of the new DFA matching code (see
 3402:     below) to a single monolithic source would have made it really too
 3403:     unwieldy, quite apart from causing all the code to be include in a
 3404:     statically linked application, when only some functions are used. This is
 3405:     relevant even without the DFA addition now that patterns can be compiled in
 3406:     one application and matched in another.
 3407: 
 3408:     The downside of splitting up is that there have to be some external
 3409:     functions and data tables that are used internally in different modules of
 3410:     the library but which are not part of the API. These have all had their
 3411:     names changed to start with "_pcre_" so that they are unlikely to clash
 3412:     with other external names.
 3413: 
 3414:  4. Added an alternate matching function, pcre_dfa_exec(), which matches using
 3415:     a different (DFA) algorithm. Although it is slower than the original
 3416:     function, it does have some advantages for certain types of matching
 3417:     problem.
 3418: 
 3419:  5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
 3420:     including restarting after a partial match.
 3421: 
 3422:  6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
 3423:     defined when compiling for Windows was sent to me. I have put it into the
 3424:     code, though I have no means of testing or verifying it.
 3425: 
 3426:  7. Added the pcre_refcount() auxiliary function.
 3427: 
 3428:  8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
 3429:     match before or at the first newline in the subject string. In pcretest,
 3430:     the /f option on a pattern can be used to set this.
 3431: 
 3432:  9. A repeated \w when used in UTF-8 mode with characters greater than 256
 3433:     would behave wrongly. This has been present in PCRE since release 4.0.
 3434: 
 3435: 10. A number of changes to the pcregrep command:
 3436: 
 3437:     (a) Refactored how -x works; insert ^(...)$ instead of setting
 3438:         PCRE_ANCHORED and checking the length, in preparation for adding
 3439:         something similar for -w.
 3440: 
 3441:     (b) Added the -w (match as a word) option.
 3442: 
 3443:     (c) Refactored the way lines are read and buffered so as to have more
 3444:         than one at a time available.
 3445: 
 3446:     (d) Implemented a pcregrep test script.
 3447: 
 3448:     (e) Added the -M (multiline match) option. This allows patterns to match
 3449:         over several lines of the subject. The buffering ensures that at least
 3450:         8K, or the rest of the document (whichever is the shorter) is available
 3451:         for matching (and similarly the previous 8K for lookbehind assertions).
 3452: 
 3453:     (f) Changed the --help output so that it now says
 3454: 
 3455:           -w, --word-regex(p)
 3456: 
 3457:         instead of two lines, one with "regex" and the other with "regexp"
 3458:         because that confused at least one person since the short forms are the
 3459:         same. (This required a bit of code, as the output is generated
 3460:         automatically from a table. It wasn't just a text change.)
 3461: 
 3462:     (g) -- can be used to terminate pcregrep options if the next thing isn't an
 3463:         option but starts with a hyphen. Could be a pattern or a path name
 3464:         starting with a hyphen, for instance.
 3465: 
 3466:     (h) "-" can be given as a file name to represent stdin.
 3467: 
 3468:     (i) When file names are being printed, "(standard input)" is used for
 3469:         the standard input, for compatibility with GNU grep. Previously
 3470:         "<stdin>" was used.
 3471: 
 3472:     (j) The option --label=xxx can be used to supply a name to be used for
 3473:         stdin when file names are being printed. There is no short form.
 3474: 
 3475:     (k) Re-factored the options decoding logic because we are going to add
 3476:         two more options that take data. Such options can now be given in four
 3477:         different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
 3478: 
 3479:     (l) Added the -A, -B, and -C options for requesting that lines of context
 3480:         around matches be printed.
 3481: 
 3482:     (m) Added the -L option to print the names of files that do not contain
 3483:         any matching lines, that is, the complement of -l.
 3484: 
 3485:     (n) The return code is 2 if any file cannot be opened, but pcregrep does
 3486:         continue to scan other files.
 3487: 
 3488:     (o) The -s option was incorrectly implemented. For compatibility with other
 3489:         greps, it now suppresses the error message for a non-existent or non-
 3490:         accessible file (but not the return code). There is a new option called
 3491:         -q that suppresses the output of matching lines, which was what -s was
 3492:         previously doing.
 3493: 
 3494:     (p) Added --include and --exclude options to specify files for inclusion
 3495:         and exclusion when recursing.
 3496: 
 3497: 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
 3498:     Hopefully, it now does.
 3499: 
 3500: 12. Missing cast in pcre_study().
 3501: 
 3502: 13. Added an "uninstall" target to the makefile.
 3503: 
 3504: 14. Replaced "extern" in the function prototypes in Makefile.in with
 3505:     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
 3506:     world, but is set differently for Windows.
 3507: 
 3508: 15. Added a second compiling function called pcre_compile2(). The only
 3509:     difference is that it has an extra argument, which is a pointer to an
 3510:     integer error code. When there is a compile-time failure, this is set
 3511:     non-zero, in addition to the error test pointer being set to point to an
 3512:     error message. The new argument may be NULL if no error number is required
 3513:     (but then you may as well call pcre_compile(), which is now just a
 3514:     wrapper). This facility is provided because some applications need a
 3515:     numeric error indication, but it has also enabled me to tidy up the way
 3516:     compile-time errors are handled in the POSIX wrapper.
 3517: 
 3518: 16. Added VPATH=.libs to the makefile; this should help when building with one
 3519:     prefix path and installing with another. (Or so I'm told by someone who
 3520:     knows more about this stuff than I do.)
 3521: 
 3522: 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
 3523:     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
 3524:     match everything, including newlines. This is not POSIX-compatible, but
 3525:     somebody wanted the feature. From pcretest it can be activated by using
 3526:     both the P and the s flags.
 3527: 
 3528: 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
 3529: 
 3530: 19. libpcre.pc was being incorrectly installed as executable.
 3531: 
 3532: 20. A couple of places in pcretest check for end-of-line by looking for '\n';
 3533:     it now also looks for '\r' so that it will work unmodified on Windows.
 3534: 
 3535: 21. Added Google's contributed C++ wrapper to the distribution.
 3536: 
 3537: 22. Added some untidy missing memory free() calls in pcretest, to keep
 3538:     Electric Fence happy when testing.
 3539: 
 3540: 
 3541: 
 3542: Version 5.0 13-Sep-04
 3543: ---------------------
 3544: 
 3545:  1. Internal change: literal characters are no longer packed up into items
 3546:     containing multiple characters in a single byte-string. Each character
 3547:     is now matched using a separate opcode. However, there may be more than one
 3548:     byte in the character in UTF-8 mode.
 3549: 
 3550:  2. The pcre_callout_block structure has two new fields: pattern_position and
 3551:     next_item_length. These contain the offset in the pattern to the next match
 3552:     item, and its length, respectively.
 3553: 
 3554:  3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
 3555:     insertion of callouts before each pattern item. Added the /C option to
 3556:     pcretest to make use of this.
 3557: 
 3558:  4. On the advice of a Windows user, the lines
 3559: 
 3560:       #if defined(_WIN32) || defined(WIN32)
 3561:       _setmode( _fileno( stdout ), 0x8000 );
 3562:       #endif  /* defined(_WIN32) || defined(WIN32) */
 3563: 
 3564:     have been added to the source of pcretest. This apparently does useful
 3565:     magic in relation to line terminators.
 3566: 
 3567:  5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
 3568:     for the benefit of those environments where the "b" makes a difference.
 3569: 
 3570:  6. The icc compiler has the same options as gcc, but "configure" doesn't seem
 3571:     to know about it. I have put a hack into configure.in that adds in code
 3572:     to set GCC=yes if CC=icc. This seems to end up at a point in the
 3573:     generated configure script that is early enough to affect the setting of
 3574:     compiler options, which is what is needed, but I have no means of testing
 3575:     whether it really works. (The user who reported this had patched the
 3576:     generated configure script, which of course I cannot do.)
 3577: 
 3578:     LATER: After change 22 below (new libtool files), the configure script
 3579:     seems to know about icc (and also ecc). Therefore, I have commented out
 3580:     this hack in configure.in.
 3581: 
 3582:  7. Added support for pkg-config (2 patches were sent in).
 3583: 
 3584:  8. Negated POSIX character classes that used a combination of internal tables
 3585:     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
 3586:     [[:^ascii]]. Typically, they would match almost any characters. The other
 3587:     POSIX classes were not broken in this way.
 3588: 
 3589:  9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
 3590:     to find the match, as PCRE was deluded into thinking that the match had to
 3591:     start at the start point or following a newline. The same bug applied to
 3592:     patterns with negative forward assertions or any backward assertions
 3593:     preceding ".*" at the start, unless the pattern required a fixed first
 3594:     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
 3595: 
 3596: 10. In UTF-8 mode, when moving forwards in the subject after a failed match
 3597:     starting at the last subject character, bytes beyond the end of the subject
 3598:     string were read.
 3599: 
 3600: 11. Renamed the variable "class" as "classbits" to make life easier for C++
 3601:     users. (Previously there was a macro definition, but it apparently wasn't
 3602:     enough.)
 3603: 
 3604: 12. Added the new field "tables" to the extra data so that tables can be passed
 3605:     in at exec time, or the internal tables can be re-selected. This allows
 3606:     a compiled regex to be saved and re-used at a later time by a different
 3607:     program that might have everything at different addresses.
 3608: 
 3609: 13. Modified the pcre-config script so that, when run on Solaris, it shows a
 3610:     -R library as well as a -L library.
 3611: 
 3612: 14. The debugging options of pcretest (-d on the command line or D on a
 3613:     pattern) showed incorrect output for anything following an extended class
 3614:     that contained multibyte characters and which was followed by a quantifier.
 3615: 
 3616: 15. Added optional support for general category Unicode character properties
 3617:     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
 3618:     support. It adds about 90K to the size of the library. The meanings of the
 3619:     inbuilt class escapes such as \d and \s have NOT been changed.
 3620: 
 3621: 16. Updated pcredemo.c to include calls to free() to release the memory for the
 3622:     compiled pattern.
 3623: 
 3624: 17. The generated file chartables.c was being created in the source directory
 3625:     instead of in the building directory. This caused the build to fail if the
 3626:     source directory was different from the building directory, and was
 3627:     read-only.
 3628: 
 3629: 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
 3630:     file. No doubt somebody will tell me if they don't make sense... Also added
 3631:     Dan Mooney's comments about building on OpenVMS.
 3632: 
 3633: 19. Added support for partial matching via the PCRE_PARTIAL option for
 3634:     pcre_exec() and the \P data escape in pcretest.
 3635: 
 3636: 20. Extended pcretest with 3 new pattern features:
 3637: 
 3638:     (i)   A pattern option of the form ">rest-of-line" causes pcretest to
 3639:           write the compiled pattern to the file whose name is "rest-of-line".
 3640:           This is a straight binary dump of the data, with the saved pointer to
 3641:           the character tables forced to be NULL. The study data, if any, is
 3642:           written too. After writing, pcretest reads a new pattern.
 3643: 
 3644:     (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
 3645:           compiled pattern from the given file. There must not be any
 3646:           occurrences of "<" in the file name (pretty unlikely); if there are,
 3647:           pcretest will instead treat the initial "<" as a pattern delimiter.
 3648:           After reading in the pattern, pcretest goes on to read data lines as
 3649:           usual.
 3650: 
 3651:     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
 3652:           and 16-bit fields in a compiled pattern, to simulate a pattern that
 3653:           was compiled on a host of opposite endianness.
 3654: 
 3655: 21. The pcre-exec() function can now cope with patterns that were compiled on
 3656:     hosts of opposite endianness, with this restriction:
 3657: 
 3658:       As for any compiled expression that is saved and used later, the tables
 3659:       pointer field cannot be preserved; the extra_data field in the arguments
 3660:       to pcre_exec() should be used to pass in a tables address if a value
 3661:       other than the default internal tables were used at compile time.
 3662: 
 3663: 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
 3664:     now diagnosed as an error. Previously, most of the time, a negative number
 3665:     would have been treated as zero, but if in addition "ovector" was passed as
 3666:     NULL, a crash could occur.
 3667: 
 3668: 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
 3669:     new versions from the libtool 1.5 distribution (the last one is a copy of
 3670:     a file called libtool.m4). This seems to have fixed the need to patch
 3671:     "configure" to support Darwin 1.3 (which I used to do). However, I still
 3672:     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
 3673:     workstation).
 3674: 
 3675: 24. Changed the PCRE licence to be the more standard "BSD" licence.
 3676: 
 3677: 
 3678: Version 4.5 01-Dec-03
 3679: ---------------------
 3680: 
 3681:  1. There has been some re-arrangement of the code for the match() function so
 3682:     that it can be compiled in a version that does not call itself recursively.
 3683:     Instead, it keeps those local variables that need separate instances for
 3684:     each "recursion" in a frame on the heap, and gets/frees frames whenever it
 3685:     needs to "recurse". Keeping track of where control must go is done by means
 3686:     of setjmp/longjmp. The whole thing is implemented by a set of macros that
 3687:     hide most of the details from the main code, and operates only if
 3688:     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
 3689:     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
 3690:     operating.
 3691: 
 3692:     To make it easier for callers to provide specially tailored get/free
 3693:     functions for this usage, two new functions, pcre_stack_malloc, and
 3694:     pcre_stack_free, are used. They are always called in strict stacking order,
 3695:     and the size of block requested is always the same.
 3696: 
 3697:     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
 3698:     PCRE has been compiled to use the stack or the heap for recursion. The
 3699:     -C option of pcretest uses this to show which version is compiled.
 3700: 
 3701:     A new data escape \S, is added to pcretest; it causes the amounts of store
 3702:     obtained and freed by both kinds of malloc/free at match time to be added
 3703:     to the output.
 3704: 
 3705:  2. Changed the locale test to use "fr_FR" instead of "fr" because that's
 3706:     what's available on my current Linux desktop machine.
 3707: 
 3708:  3. When matching a UTF-8 string, the test for a valid string at the start has
 3709:     been extended. If start_offset is not zero, PCRE now checks that it points
 3710:     to a byte that is the start of a UTF-8 character. If not, it returns
 3711:     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
 3712:     this is necessary because there may be backward assertions in the pattern.
 3713:     When matching the same subject several times, it may save resources to use
 3714:     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
 3715: 
 3716:  4. The code for checking the validity of UTF-8 strings has been tightened so
 3717:     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
 3718:     containing "overlong sequences".
 3719: 
 3720:  5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
 3721:     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
 3722:     should have been "&", but it just so happened that all the cases this let
 3723:     through by mistake were picked up later in the function.
 3724: 
 3725:  6. I had used a variable called "isblank" - this is a C99 function, causing
 3726:     some compilers to warn. To avoid this, I renamed it (as "blankclass").
 3727: 
 3728:  7. Cosmetic: (a) only output another newline at the end of pcretest if it is
 3729:     prompting; (b) run "./pcretest /dev/null" at the start of the test script
 3730:     so the version is shown; (c) stop "make test" echoing "./RunTest".
 3731: 
 3732:  8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
 3733: 
 3734:  9. The prototype for memmove() for systems that don't have it was using
 3735:     size_t, but the inclusion of the header that defines size_t was later. I've
 3736:     moved the #includes for the C headers earlier to avoid this.
 3737: 
 3738: 10. Added some adjustments to the code to make it easier to compiler on certain
 3739:     special systems:
 3740: 
 3741:       (a) Some "const" qualifiers were missing.
 3742:       (b) Added the macro EXPORT before all exported functions; by default this
 3743:           is defined to be empty.
 3744:       (c) Changed the dftables auxiliary program (that builds chartables.c) so
 3745:           that it reads its output file name as an argument instead of writing
 3746:           to the standard output and assuming this can be redirected.
 3747: 
 3748: 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
 3749:     class containing characters with values greater than 255, PCRE compilation
 3750:     went into a loop.
 3751: 
 3752: 12. A recursive reference to a subpattern that was within another subpattern
 3753:     that had a minimum quantifier of zero caused PCRE to crash. For example,
 3754:     (x(y(?2))z)? provoked this bug with a subject that got as far as the
 3755:     recursion. If the recursively-called subpattern itself had a zero repeat,
 3756:     that was OK.
 3757: 
 3758: 13. In pcretest, the buffer for reading a data line was set at 30K, but the
 3759:     buffer into which it was copied (for escape processing) was still set at
 3760:     1024, so long lines caused crashes.
 3761: 
 3762: 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
 3763:     "internal error: code overflow...". This applied to any character class
 3764:     that was followed by a possessive quantifier.
 3765: 
 3766: 15. Modified the Makefile to add libpcre.la as a prerequisite for
 3767:     libpcreposix.la because I was told this is needed for a parallel build to
 3768:     work.
 3769: 
 3770: 16. If a pattern that contained .* following optional items at the start was
 3771:     studied, the wrong optimizing data was generated, leading to matching
 3772:     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
 3773:     matching string must start with a or b or c. The correct conclusion for
 3774:     this pattern is that a match can start with any character.
 3775: 
 3776: 
 3777: Version 4.4 13-Aug-03
 3778: ---------------------
 3779: 
 3780:  1. In UTF-8 mode, a character class containing characters with values between
 3781:     127 and 255 was not handled correctly if the compiled pattern was studied.
 3782:     In fixing this, I have also improved the studying algorithm for such
 3783:     classes (slightly).
 3784: 
 3785:  2. Three internal functions had redundant arguments passed to them. Removal
 3786:     might give a very teeny performance improvement.
 3787: 
 3788:  3. Documentation bug: the value of the capture_top field in a callout is *one
 3789:     more than* the number of the hightest numbered captured substring.
 3790: 
 3791:  4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
 3792:     in incorrectly linking with a previously installed version. They now link
 3793:     explicitly with libpcre.la.
 3794: 
 3795:  5. configure.in no longer needs to recognize Cygwin specially.
 3796: 
 3797:  6. A problem in pcre.in for Windows platforms is fixed.
 3798: 
 3799:  7. If a pattern was successfully studied, and the -d (or /D) flag was given to
 3800:     pcretest, it used to include the size of the study block as part of its
 3801:     output. Unfortunately, the structure contains a field that has a different
 3802:     size on different hardware architectures. This meant that the tests that
 3803:     showed this size failed. As the block is currently always of a fixed size,
 3804:     this information isn't actually particularly useful in pcretest output, so
 3805:     I have just removed it.
 3806: 
 3807:  8. Three pre-processor statements accidentally did not start in column 1.
 3808:     Sadly, there are *still* compilers around that complain, even though
 3809:     standard C has not required this for well over a decade. Sigh.
 3810: 
 3811:  9. In pcretest, the code for checking callouts passed small integers in the
 3812:     callout_data field, which is a void * field. However, some picky compilers
 3813:     complained about the casts involved for this on 64-bit systems. Now
 3814:     pcretest passes the address of the small integer instead, which should get
 3815:     rid of the warnings.
 3816: 
 3817: 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
 3818:     both compile and run time, and gives an error if an invalid UTF-8 sequence
 3819:     is found. There is a option for disabling this check in cases where the
 3820:     string is known to be correct and/or the maximum performance is wanted.
 3821: 
 3822: 11. In response to a bug report, I changed one line in Makefile.in from
 3823: 
 3824:         -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
 3825:     to
 3826:         -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
 3827: 
 3828:     to look similar to other lines, but I have no way of telling whether this
 3829:     is the right thing to do, as I do not use Windows. No doubt I'll get told
 3830:     if it's wrong...
 3831: 
 3832: 
 3833: Version 4.3 21-May-03
 3834: ---------------------
 3835: 
 3836: 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
 3837:    Makefile.
 3838: 
 3839: 2. Some refactoring to improve the quality of the code:
 3840: 
 3841:    (i)   The utf8_table... variables are now declared "const".
 3842: 
 3843:    (ii)  The code for \cx, which used the "case flipping" table to upper case
 3844:          lower case letters, now just substracts 32. This is ASCII-specific,
 3845:          but the whole concept of \cx is ASCII-specific, so it seems
 3846:          reasonable.
 3847: 
 3848:    (iii) PCRE was using its character types table to recognize decimal and
 3849:          hexadecimal digits in the pattern. This is silly, because it handles
 3850:          only 0-9, a-f, and A-F, but the character types table is locale-
 3851:          specific, which means strange things might happen. A private
 3852:          table is now used for this - though it costs 256 bytes, a table is
 3853:          much faster than multiple explicit tests. Of course, the standard
 3854:          character types table is still used for matching digits in subject
 3855:          strings against \d.
 3856: 
 3857:    (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
 3858:          ending in _t are). So I've renamed it as ESC_tee.
 3859: 
 3860: 3. The first argument for regexec() in the POSIX wrapper should have been
 3861:    defined as "const".
 3862: 
 3863: 4. Changed pcretest to use malloc() for its buffers so that they can be
 3864:    Electric Fenced for debugging.
 3865: 
 3866: 5. There were several places in the code where, in UTF-8 mode, PCRE would try
 3867:    to read one or more bytes before the start of the subject string. Often this
 3868:    had no effect on PCRE's behaviour, but in some circumstances it could
 3869:    provoke a segmentation fault.
 3870: 
 3871: 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
 3872:    to try to read one or more bytes before the start of the subject string.
 3873: 
 3874: 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
 3875:    UTF-8 support could misbehave in various ways if the subject string
 3876:    contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
 3877:    area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
 3878:    back over UTF-8 characters.)
 3879: 
 3880: 
 3881: Version 4.2 14-Apr-03
 3882: ---------------------
 3883: 
 3884: 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
 3885: 
 3886: 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
 3887:      [ON_WINDOWS]: new variable, "#" on non-Windows platforms
 3888:      [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
 3889:      [WIN_PREFIX]: new variable, "cyg" for Cygwin
 3890:      * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
 3891:        and BUILD_EXEEXT
 3892:      Note: automatic setting of the BUILD variables is not yet working
 3893:      set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
 3894:        compile-time but not at link-time
 3895:      [LINK]: use for linking executables only
 3896:      make different versions for Windows and non-Windows
 3897:      [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
 3898:        libraries
 3899:      [LINK_FOR_BUILD]: new variable
 3900:      [OBJEXT]: use throughout
 3901:      [EXEEXT]: use throughout
 3902:      <winshared>: new target
 3903:      <wininstall>: new target
 3904:      <dftables.o>: use native compiler
 3905:      <dftables>: use native linker
 3906:      <install>: handle Windows platform correctly
 3907:      <clean>: ditto
 3908:      <check>: ditto
 3909:      copy DLL to top builddir before testing
 3910: 
 3911:    As part of these changes, -no-undefined was removed again. This was reported
 3912:    to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
 3913:    in any case.
 3914: 
 3915: 3. Some tidies to get rid of compiler warnings:
 3916: 
 3917:    . In the match_data structure, match_limit was an unsigned long int, whereas
 3918:      match_call_count was an int. I've made them both unsigned long ints.
 3919: 
 3920:    . In pcretest the fact that a const uschar * doesn't automatically cast to
 3921:      a void * provoked a warning.
 3922: 
 3923:    . Turning on some more compiler warnings threw up some "shadow" variables
 3924:      and a few more missing casts.
 3925: 
 3926: 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
 3927:    option, a class that contained a single character with a value between 128
 3928:    and 255 (e.g. /[\xFF]/) caused PCRE to crash.
 3929: 
 3930: 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
 3931:    option, a class that contained several characters, but with at least one
 3932:    whose value was between 128 and 255 caused PCRE to crash.
 3933: 
 3934: 
 3935: Version 4.1 12-Mar-03
 3936: ---------------------
 3937: 
 3938: 1. Compiling with gcc -pedantic found a couple of places where casts were
 3939: needed, and a string in dftables.c that was longer than standard compilers are
 3940: required to support.
 3941: 
 3942: 2. Compiling with Sun's compiler found a few more places where the code could
 3943: be tidied up in order to avoid warnings.
 3944: 
 3945: 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
 3946: first of these names is deprecated in the latest Autoconf in favour of the name
 3947: CC_FOR_BUILD, because "host" is typically used to mean the system on which the
 3948: compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
 3949: analogy I have changed it to CFLAGS_FOR_BUILD.
 3950: 
 3951: 4. Added -no-undefined to the linking command in the Makefile, because this is
 3952: apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
 3953: linking step for the pcreposix library.
 3954: 
 3955: 5. PCRE was failing to diagnose the case of two named groups with the same
 3956: name.
 3957: 
 3958: 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
 3959: literal character that is needed in the subject for a match, and scans along to
 3960: ensure that it is present before embarking on the full matching process. This
 3961: saves time in cases of nested unlimited repeats that are never going to match.
 3962: Problem: the scan can take a lot of time if the subject is very long (e.g.
 3963: megabytes), thus penalizing straightforward matches. It is now done only if the
 3964: amount of subject to be scanned is less than 1000 bytes.
 3965: 
 3966: 7. A lesser problem with the same optimization is that it was recording the
 3967: first character of an anchored pattern as "needed", thus provoking a search
 3968: right along the subject, even when the first match of the pattern was going to
 3969: fail. The "needed" character is now not set for anchored patterns, unless it
 3970: follows something in the pattern that is of non-fixed length. Thus, it still
 3971: fulfils its original purpose of finding quick non-matches in cases of nested
 3972: unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
 3973: 
 3974: 
 3975: Version 4.0 17-Feb-03
 3976: ---------------------
 3977: 
 3978: 1. If a comment in an extended regex that started immediately after a meta-item
 3979: extended to the end of string, PCRE compiled incorrect data. This could lead to
 3980: all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
 3981: 
 3982: 2. Moved to autoconf 2.53 and libtool 1.4.2.
 3983: 
 3984: 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
 3985: the special perltest8 script is no longer needed - all the tests can be run
 3986: from a single perltest script.
 3987: 
 3988: 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
 3989: by \s. It has now been removed in PCRE. This means it isn't recognized as
 3990: whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
 3991: class [:space:] *does* include VT, thereby creating a mess.
 3992: 
 3993: 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
 3994: space and tab.
 3995: 
 3996: 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
 3997: its new features into the main test script, reducing the number of scripts.
 3998: 
 3999: 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
 4000: were backward compatible, and made the (?i) apply to the whole pattern, as if
 4001: /i were given. Now it behaves more logically, and applies the option setting
 4002: only to what follows. PCRE has been changed to follow suit. However, if it
 4003: finds options settings right at the start of the pattern, it extracts them into
 4004: the global options, as before. Thus, they show up in the info data.
 4005: 
 4006: 8. Added support for the \Q...\E escape sequence. Characters in between are
 4007: treated as literals. This is slightly different from Perl in that $ and @ are
 4008: also handled as literals inside the quotes. In Perl, they will cause variable
 4009: interpolation. Note the following examples:
 4010: 
 4011:     Pattern            PCRE matches      Perl matches
 4012: 
 4013:     \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
 4014:     \Qabc\$xyz\E       abc\$xyz          abc\$xyz
 4015:     \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
 4016: 
 4017: For compatibility with Perl, \Q...\E sequences are recognized inside character
 4018: classes as well as outside them.
 4019: 
 4020: 9. Re-organized 3 code statements in pcretest to avoid "overflow in
 4021: floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
 4022: (size_t) cast to one statement in pcretest and one in pcreposix to avoid
 4023: signed/unsigned warnings.
 4024: 
 4025: 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
 4026: option for pcretest, so I've replaced it by a simple function that does just
 4027: that job.
 4028: 
 4029: 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
 4030: "pcregrep -".
 4031: 
 4032: 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
 4033: Java package. This provides some syntactic sugar for simple cases of what my
 4034: documentation calls "once-only subpatterns". A pattern such as x*+ is the same
 4035: as (?>x*). In other words, if what is inside (?>...) is just a single repeated
 4036: item, you can use this simplified notation. Note that only makes sense with
 4037: greedy quantifiers. Consequently, the use of the possessive quantifier forces
 4038: greediness, whatever the setting of the PCRE_UNGREEDY option.
 4039: 
 4040: 13. A change of greediness default within a pattern was not taking effect at
 4041: the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
 4042: subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
 4043: was abstracted outside.
 4044: 
 4045: 14. PCRE now supports the \G assertion. It is true when the current matching
 4046: position is at the start point of the match. This differs from \A when the
 4047: starting offset is non-zero. Used with the /g option of pcretest (or similar
 4048: code), it works in the same way as it does for Perl's /g option. If all
 4049: alternatives of a regex begin with \G, the expression is anchored to the start
 4050: match position, and the "anchored" flag is set in the compiled expression.
 4051: 
 4052: 15. Some bugs concerning the handling of certain option changes within patterns
 4053: have been fixed. These applied to options other than (?ims). For example,
 4054: "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
 4055: been the other way round. Some of this was related to change 7 above.
 4056: 
 4057: 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
 4058: features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
 4059: and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
 4060: POSIX classes only within a class (e.g. /[[:alpha:]]/).
 4061: 
 4062: 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
 4063: mode. Unlike ".", it always matches newline, whatever the setting of
 4064: PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
 4065: assertions. Perl allows it, but it doesn't (in general) work because it can't
 4066: calculate the length of the lookbehind. At least, that's the case for Perl
 4067: 5.8.0 - I've been told they are going to document that it doesn't work in
 4068: future.
 4069: 
 4070: 18. Added an error diagnosis for escapes that PCRE does not support: these are
 4071: \L, \l, \N, \P, \p, \U, \u, and \X.
 4072: 
 4073: 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
 4074: reading past the end of the pattern in cases such as /[abcd/.
 4075: 
 4076: 20. PCRE was getting more memory than necessary for patterns with classes that
 4077: contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
 4078: 
 4079: 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
 4080: compiling PCRE for use with Virtual Pascal.
 4081: 
 4082: 22. Small fix to the Makefile to make it work properly if the build is done
 4083: outside the source tree.
 4084: 
 4085: 23. Added a new extension: a condition to go with recursion. If a conditional
 4086: subpattern starts with (?(R) the "true" branch is used if recursion has
 4087: happened, whereas the "false" branch is used only at the top level.
 4088: 
 4089: 24. When there was a very long string of literal characters (over 255 bytes
 4090: without UTF support, over 250 bytes with UTF support), the computation of how
 4091: much memory was required could be incorrect, leading to segfaults or other
 4092: strange effects.
 4093: 
 4094: 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
 4095: start of line for a non-DOTALL pattern) when a pattern started with (.*) and
 4096: there was a subsequent back reference to those brackets. This meant that, for
 4097: example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
 4098: possible to check for precisely this case. All we can do is abandon the
 4099: optimization if .* occurs inside capturing brackets when there are any back
 4100: references whatsoever. (See below for a better fix that came later.)
 4101: 
 4102: 26. The handling of the optimization for finding the first character of a
 4103: non-anchored pattern, and for finding a character that is required later in the
 4104: match were failing in some cases. This didn't break the matching; it just
 4105: failed to optimize when it could. The way this is done has been re-implemented.
 4106: 
 4107: 27. Fixed typo in error message for invalid (?R item (it said "(?p").
 4108: 
 4109: 28. Added a new feature that provides some of the functionality that Perl
 4110: provides with (?{...}). The facility is termed a "callout". The way it is done
 4111: in PCRE is for the caller to provide an optional function, by setting
 4112: pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
 4113: global variable. By default it is unset, which disables all calling out. To get
 4114: the function called, the regex must include (?C) at appropriate points. This
 4115: is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
 4116: This provides a means of identifying different callout points. When PCRE
 4117: reaches such a point in the regex, if pcre_callout has been set, the external
 4118: function is called. It is provided with data in a structure called
 4119: pcre_callout_block, which is defined in pcre.h. If the function returns 0,
 4120: matching continues; if it returns a non-zero value, the match at the current
 4121: point fails. However, backtracking will occur if possible. [This was changed
 4122: later and other features added - see item 49 below.]
 4123: 
 4124: 29. pcretest is upgraded to test the callout functionality. It provides a
 4125: callout function that displays information. By default, it shows the start of
 4126: the match and the current position in the text. There are some new data escapes
 4127: to vary what happens:
 4128: 
 4129:     \C+         in addition, show current contents of captured substrings
 4130:     \C-         do not supply a callout function
 4131:     \C!n        return 1 when callout number n is reached
 4132:     \C!n!m      return 1 when callout number n is reached for the mth time
 4133: 
 4134: 30. If pcregrep was called with the -l option and just a single file name, it
 4135: output "<stdin>" if a match was found, instead of the file name.
 4136: 
 4137: 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
 4138: slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
 4139: pcre_exec(). This saves a malloc/free per call. The default value of
 4140: POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
 4141: when configuring.
 4142: 
 4143: 32. The default maximum size of a compiled pattern is 64K. There have been a
 4144: few cases of people hitting this limit. The code now uses macros to handle the
 4145: storing of links as offsets within the compiled pattern. It defaults to 2-byte
 4146: links, but this can be changed to 3 or 4 bytes by --with-link-size when
 4147: configuring. Tests 2 and 5 work only with 2-byte links because they output
 4148: debugging information about compiled patterns.
 4149: 
 4150: 33. Internal code re-arrangements:
 4151: 
 4152: (a) Moved the debugging function for printing out a compiled regex into
 4153:     its own source file (printint.c) and used #include to pull it into
 4154:     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
 4155:     separate copies.
 4156: 
 4157: (b) Defined the list of op-code names for debugging as a macro in
 4158:     internal.h so that it is next to the definition of the opcodes.
 4159: 
 4160: (c) Defined a table of op-code lengths for simpler skipping along compiled
 4161:     code. This is again a macro in internal.h so that it is next to the
 4162:     definition of the opcodes.
 4163: 
 4164: 34. Added support for recursive calls to individual subpatterns, along the
 4165: lines of Robin Houston's patch (but implemented somewhat differently).
 4166: 
 4167: 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
 4168: allow it to read and process whole directories in Win32. This code was
 4169: contributed by Lionel Fourquaux; it has not been tested by me.
 4170: 
 4171: 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
 4172: used to name a group. Names consist of alphanumerics and underscores, and must
 4173: be unique. Back references use the syntax (?P=name) and recursive calls use
 4174: (?P>name) which is a PCRE extension to the Python extension. Groups still have
 4175: numbers. The function pcre_fullinfo() can be used after compilation to extract
 4176: a name/number map. There are three relevant calls:
 4177: 
 4178:   PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
 4179:   PCRE_INFO_NAMECOUNT            yields the number of entries
 4180:   PCRE_INFO_NAMETABLE            yields a pointer to the map.
 4181: 
 4182: The map is a vector of fixed-size entries. The size of each entry depends on
 4183: the length of the longest name used. The first two bytes of each entry are the
 4184: group number, most significant byte first. There follows the corresponding
 4185: name, zero terminated. The names are in alphabetical order.
 4186: 
 4187: 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
 4188: case instead of 255. Making it the same both with and without UTF-8 support
 4189: means that the same test output works with both.
 4190: 
 4191: 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
 4192: calling malloc() with a zero argument.
 4193: 
 4194: 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
 4195: optimization. I've improved things by keeping a bitmap of backreferences with
 4196: numbers 1-31 so that if .* occurs inside capturing brackets that are not in
 4197: fact referenced, the optimization can be applied. It is unlikely that a
 4198: relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
 4199: the match to follow \n) will appear inside brackets with a number greater than
 4200: 31, but if it does, any back reference > 31 suppresses the optimization.
 4201: 
 4202: 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
 4203: of disabling numbered capturing parentheses. Any opening parenthesis that is
 4204: not followed by ? behaves as if it were followed by ?: but named parentheses
 4205: can still be used for capturing (and they will acquire numbers in the usual
 4206: way).
 4207: 
 4208: 41. Redesigned the return codes from the match() function into yes/no/error so
 4209: that errors can be passed back from deep inside the nested calls. A malloc
 4210: failure while inside a recursive subpattern call now causes the
 4211: PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
 4212: 
 4213: 42. It is now possible to set a limit on the number of times the match()
 4214: function is called in a call to pcre_exec(). This facility makes it possible to
 4215: limit the amount of recursion and backtracking, though not in a directly
 4216: obvious way, because the match() function is used in a number of different
 4217: circumstances. The count starts from zero for each position in the subject
 4218: string (for non-anchored patterns). The default limit is, for compatibility, a
 4219: large number, namely 10 000 000. You can change this in two ways:
 4220: 
 4221: (a) When configuring PCRE before making, you can use --with-match-limit=n
 4222:     to set a default value for the compiled library.
 4223: 
 4224: (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
 4225:     a different value is set. See 45 below.
 4226: 
 4227: If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
 4228: 
 4229: 43. Added a new function pcre_config(int, void *) to enable run-time extraction
 4230: of things that can be changed at compile time. The first argument specifies
 4231: what is wanted and the second points to where the information is to be placed.
 4232: The current list of available information is:
 4233: 
 4234:   PCRE_CONFIG_UTF8
 4235: 
 4236: The output is an integer that is set to one if UTF-8 support is available;
 4237: otherwise it is set to zero.
 4238: 
 4239:   PCRE_CONFIG_NEWLINE
 4240: 
 4241: The output is an integer that it set to the value of the code that is used for
 4242: newline. It is either LF (10) or CR (13).
 4243: 
 4244:   PCRE_CONFIG_LINK_SIZE
 4245: 
 4246: The output is an integer that contains the number of bytes used for internal
 4247: linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
 4248: 
 4249:   PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
 4250: 
 4251: The output is an integer that contains the threshold above which the POSIX
 4252: interface uses malloc() for output vectors. See item 31 above.
 4253: 
 4254:   PCRE_CONFIG_MATCH_LIMIT
 4255: 
 4256: The output is an unsigned integer that contains the default limit of the number
 4257: of match() calls in a pcre_exec() execution. See 42 above.
 4258: 
 4259: 44. pcretest has been upgraded by the addition of the -C option. This causes it
 4260: to extract all the available output from the new pcre_config() function, and to
 4261: output it. The program then exits immediately.
 4262: 
 4263: 45. A need has arisen to pass over additional data with calls to pcre_exec() in
 4264: order to support additional features. One way would have been to define
 4265: pcre_exec2() (for example) with extra arguments, but this would not have been
 4266: extensible, and would also have required all calls to the original function to
 4267: be mapped to the new one. Instead, I have chosen to extend the mechanism that
 4268: is used for passing in "extra" data from pcre_study().
 4269: 
 4270: The pcre_extra structure is now exposed and defined in pcre.h. It currently
 4271: contains the following fields:
 4272: 
 4273:   flags         a bitmap indicating which of the following fields are set
 4274:   study_data    opaque data from pcre_study()
 4275:   match_limit   a way of specifying a limit on match() calls for a specific
 4276:                   call to pcre_exec()
 4277:   callout_data  data for callouts (see 49 below)
 4278: 
 4279: The flag bits are also defined in pcre.h, and are
 4280: 
 4281:   PCRE_EXTRA_STUDY_DATA
 4282:   PCRE_EXTRA_MATCH_LIMIT
 4283:   PCRE_EXTRA_CALLOUT_DATA
 4284: 
 4285: The pcre_study() function now returns one of these new pcre_extra blocks, with
 4286: the actual study data pointed to by the study_data field, and the
 4287: PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
 4288: before. That is, this change is entirely upwards-compatible and requires no
 4289: change to existing code.
 4290: 
 4291: If you want to pass in additional data to pcre_exec(), you can either place it
 4292: in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
 4293: block.
 4294: 
 4295: 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
 4296: data string contains the escape sequence \M, pcretest calls pcre_exec() several
 4297: times with different match limits, until it finds the minimum value needed for
 4298: pcre_exec() to complete. The value is then output. This can be instructive; for
 4299: most simple matches the number is quite small, but for pathological cases it
 4300: gets very large very quickly.
 4301: 
 4302: 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
 4303: returns the size of the data block pointed to by the study_data field in a
 4304: pcre_extra block, that is, the value that was passed as the argument to
 4305: pcre_malloc() when PCRE was getting memory in which to place the information
 4306: created by pcre_study(). The fourth argument should point to a size_t variable.
 4307: pcretest has been extended so that this information is shown after a successful
 4308: pcre_study() call when information about the compiled regex is being displayed.
 4309: 
 4310: 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
 4311: because what follows is always an absolute path. (Later: it turns out that this
 4312: is more than cosmetic for MinGW, because it doesn't like empty path
 4313: components.)
 4314: 
 4315: 49. Some changes have been made to the callout feature (see 28 above):
 4316: 
 4317: (i)  A callout function now has three choices for what it returns:
 4318: 
 4319:        0  =>  success, carry on matching
 4320:      > 0  =>  failure at this point, but backtrack if possible
 4321:      < 0  =>  serious error, return this value from pcre_exec()
 4322: 
 4323:      Negative values should normally be chosen from the set of PCRE_ERROR_xxx
 4324:      values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
 4325:      "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
 4326:      use by callout functions. It will never be used by PCRE itself.
 4327: 
 4328: (ii) The pcre_extra structure (see 45 above) has a void * field called
 4329:      callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
 4330:      pcre_callout_block structure has a field of the same name. The contents of
 4331:      the field passed in the pcre_extra structure are passed to the callout
 4332:      function in the corresponding field in the callout block. This makes it
 4333:      easier to use the same callout-containing regex from multiple threads. For
 4334:      testing, the pcretest program has a new data escape
 4335: 
 4336:        \C*n        pass the number n (may be negative) as callout_data
 4337: 
 4338:      If the callout function in pcretest receives a non-zero value as
 4339:      callout_data, it returns that value.
 4340: 
 4341: 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
 4342: there were some redundant $(CFLAGS) in commands that are now specified as
 4343: $(LINK), which already includes $(CFLAGS).
 4344: 
 4345: 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
 4346: has been compiled with UTF-8 support *and* pcre_compile() has been compiled
 4347: with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
 4348: one-byte characters throughout. Note that case-insensitive matching applies
 4349: only to characters whose values are less than 256. PCRE doesn't support the
 4350: notion of cases for higher-valued characters.
 4351: 
 4352: (i)   A character class whose characters are all within 0-255 is handled as
 4353:       a bit map, and the map is inverted for negative classes. Previously, a
 4354:       character > 255 always failed to match such a class; however it should
 4355:       match if the class was a negative one (e.g. [^ab]). This has been fixed.
 4356: 
 4357: (ii)  A negated character class with a single character < 255 is coded as
 4358:       "not this character" (OP_NOT). This wasn't working properly when the test
 4359:       character was multibyte, either singly or repeated.
 4360: 
 4361: (iii) Repeats of multibyte characters are now handled correctly in UTF-8
 4362:       mode, for example: \x{100}{2,3}.
 4363: 
 4364: (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
 4365:       singly or repeated) now correctly test multibyte characters. However,
 4366:       PCRE doesn't recognize any characters with values greater than 255 as
 4367:       digits, spaces, or word characters. Such characters always match \D, \S,
 4368:       and \W, and never match \d, \s, or \w.
 4369: 
 4370: (v)   Classes may now contain characters and character ranges with values
 4371:       greater than 255. For example: [ab\x{100}-\x{400}].
 4372: 
 4373: (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
 4374:       PCRE in UTF-8 mode.
 4375: 
 4376: 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
 4377: PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
 4378: retained for backwards compatibility. (Note that LASTLITERAL is also a byte
 4379: value.)
 4380: 
 4381: 53. The single man page has become too large. I have therefore split it up into
 4382: a number of separate man pages. These also give rise to individual HTML pages;
 4383: these are now put in a separate directory, and there is an index.html page that
 4384: lists them all. Some hyperlinking between the pages has been installed.
 4385: 
 4386: 54. Added convenience functions for handling named capturing parentheses.
 4387: 
 4388: 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
 4389: aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
 4390: true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
 4391: are faulted.
 4392: 
 4393: 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
 4394: calling configure. These values are used when compiling the dftables.c program
 4395: which is run to generate the source of the default character tables. They
 4396: default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
 4397: you will need to set these values.
 4398: 
 4399: 57. Updated the building process for Windows DLL, as provided by Fred Cox.
 4400: 
 4401: 
 4402: Version 3.9 02-Jan-02
 4403: ---------------------
 4404: 
 4405: 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
 4406: 
 4407: 2. If --disable-static was given, the building process failed when trying to
 4408: build pcretest and pcregrep. (For some reason it was using libtool to compile
 4409: them, which is not right, as they aren't part of the library.)
 4410: 
 4411: 
 4412: Version 3.8 18-Dec-01
 4413: ---------------------
 4414: 
 4415: 1. The experimental UTF-8 code was completely screwed up. It was packing the
 4416: bytes in the wrong order. How dumb can you get?
 4417: 
 4418: 
 4419: Version 3.7 29-Oct-01
 4420: ---------------------
 4421: 
 4422: 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
 4423: This caused pcretest, when used on the test data, to segfault. Unfortunately,
 4424: this didn't happen under Solaris 8, where I normally test things.
 4425: 
 4426: 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
 4427: doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
 4428: isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
 4429: this fix an hour or so after the initial 3.7 release.)
 4430: 
 4431: 
 4432: Version 3.6 23-Oct-01
 4433: ---------------------
 4434: 
 4435: 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
 4436: offsets passed as NULL with zero offset count.
 4437: 
 4438: 2. The config.guess and config.sub files had not been updated when I moved to
 4439: the latest autoconf.
 4440: 
 4441: 
 4442: Version 3.5 15-Aug-01
 4443: ---------------------
 4444: 
 4445: 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
 4446: had been forgotten.
 4447: 
 4448: 2. By using declared but undefined structures, we can avoid using "void"
 4449: definitions in pcre.h while keeping the internal definitions of the structures
 4450: private.
 4451: 
 4452: 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
 4453: user point of view, this means that both static and shared libraries are built
 4454: by default, but this can be individually controlled. More of the work of
 4455: handling this static/shared cases is now inside libtool instead of PCRE's make
 4456: file.
 4457: 
 4458: 4. The pcretest utility is now installed along with pcregrep because it is
 4459: useful for users (to test regexs) and by doing this, it automatically gets
 4460: relinked by libtool. The documentation has been turned into a man page, so
 4461: there are now .1, .txt, and .html versions in /doc.
 4462: 
 4463: 5. Upgrades to pcregrep:
 4464:    (i)   Added long-form option names like gnu grep.
 4465:    (ii)  Added --help to list all options with an explanatory phrase.
 4466:    (iii) Added -r, --recursive to recurse into sub-directories.
 4467:    (iv)  Added -f, --file to read patterns from a file.
 4468: 
 4469: 6. pcre_exec() was referring to its "code" argument before testing that
 4470: argument for NULL (and giving an error if it was NULL).
 4471: 
 4472: 7. Upgraded Makefile.in to allow for compiling in a different directory from
 4473: the source directory.
 4474: 
 4475: 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
 4476: options bits, the pointer it was passed was to an int instead of to an unsigned
 4477: long int. This mattered only on 64-bit systems.
 4478: 
 4479: 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
 4480: generated) instead of pcre.in, which it its source. Also made the same change
 4481: in several of the .c files.
 4482: 
 4483: 10. A new release of gcc defines printf() as a macro, which broke pcretest
 4484: because it had an ifdef in the middle of a string argument for printf(). Fixed
 4485: by using separate calls to printf().
 4486: 
 4487: 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
 4488: script, to force use of CR or LF instead of \n in the source. On non-Unix
 4489: systems, the value can be set in config.h.
 4490: 
 4491: 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
 4492: absolute limit. Changed the text of the error message to make this clear, and
 4493: likewise updated the man page.
 4494: 
 4495: 13. The limit of 99 on the number of capturing subpatterns has been removed.
 4496: The new limit is 65535, which I hope will not be a "real" limit.
 4497: 
 4498: 
 4499: Version 3.4 22-Aug-00
 4500: ---------------------
 4501: 
 4502: 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
 4503: 
 4504: 2. Diagnose condition (?(0) as an error instead of crashing on matching.
 4505: 
 4506: 
 4507: Version 3.3 01-Aug-00
 4508: ---------------------
 4509: 
 4510: 1. If an octal character was given, but the value was greater than \377, it
 4511: was not getting masked to the least significant bits, as documented. This could
 4512: lead to crashes in some systems.
 4513: 
 4514: 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
 4515: the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
 4516: 
 4517: 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
 4518: These just pass their arguments on to (pcre_free)(), but they are provided
 4519: because some uses of PCRE bind it to non-C systems that can call its functions,
 4520: but cannot call free() or pcre_free() directly.
 4521: 
 4522: 4. Add "make test" as a synonym for "make check". Corrected some comments in
 4523: the Makefile.
 4524: 
 4525: 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
 4526: Makefile.
 4527: 
 4528: 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
 4529: command called pgrep for grepping around the active processes.
 4530: 
 4531: 7. Added the beginnings of support for UTF-8 character strings.
 4532: 
 4533: 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
 4534: RANLIB to ./ltconfig so that they are used by libtool. I think these are all
 4535: the relevant ones. (AR is not passed because ./ltconfig does its own figuring
 4536: out for the ar command.)
 4537: 
 4538: 
 4539: Version 3.2 12-May-00
 4540: ---------------------
 4541: 
 4542: This is purely a bug fixing release.
 4543: 
 4544: 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
 4545: of ZA. This was just one example of several cases that could provoke this bug,
 4546: which was introduced by change 9 of version 2.00. The code for breaking
 4547: infinite loops after an iteration that matches an empty string was't working
 4548: correctly.
 4549: 
 4550: 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
 4551: when matched against abbab (for example). After matching an empty string, it
 4552: wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
 4553: caused it to match further down the string than it should.
 4554: 
 4555: 3. The code contained an inclusion of sys/types.h. It isn't clear why this
 4556: was there because it doesn't seem to be needed, and it causes trouble on some
 4557: systems, as it is not a Standard C header. It has been removed.
 4558: 
 4559: 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
 4560: were reported on the Macintosh. The changes were from
 4561: 
 4562:   while ((c = *(++ptr)) != 0 && c != '\n');
 4563: to
 4564:   while ((c = *(++ptr)) != 0 && c != '\n') ;
 4565: 
 4566: Totally extraordinary, but if that's what it takes...
 4567: 
 4568: 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
 4569: available. Added HAVE_BCOPY and an autoconf test for it; if neither
 4570: HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
 4571: assumes the way PCRE uses memmove() (always moving upwards).
 4572: 
 4573: 6. PCRE is being used in one environment where strchr() is not available. There
 4574: was only one use in pcre.c, and writing it out to avoid strchr() probably gives
 4575: faster code anyway.
 4576: 
 4577: 
 4578: Version 3.1 09-Feb-00
 4579: ---------------------
 4580: 
 4581: The only change in this release is the fixing of some bugs in Makefile.in for
 4582: the "install" target:
 4583: 
 4584: (1) It was failing to install pcreposix.h.
 4585: 
 4586: (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
 4587: 
 4588: 
 4589: Version 3.0 01-Feb-00
 4590: ---------------------
 4591: 
 4592: 1. Add support for the /+ modifier to perltest (to output $` like it does in
 4593: pcretest).
 4594: 
 4595: 2. Add support for the /g modifier to perltest.
 4596: 
 4597: 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
 4598: matches null strings.
 4599: 
 4600: 4. Fix perltest so that it doesn't do unwanted things when fed an empty
 4601: pattern. Perl treats empty patterns specially - it reuses the most recent
 4602: pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
 4603: effect.
 4604: 
 4605: 5. The POSIX interface was broken in that it was just handing over the POSIX
 4606: captured string vector to pcre_exec(), but (since release 2.00) PCRE has
 4607: required a bigger vector, with some working space on the end. This means that
 4608: the POSIX wrapper now has to get and free some memory, and copy the results.
 4609: 
 4610: 6. Added some simple autoconf support, placing the test data and the
 4611: documentation in separate directories, re-organizing some of the
 4612: information files, and making it build pcre-config (a GNU standard). Also added
 4613: libtool support for building PCRE as a shared library, which is now the
 4614: default.
 4615: 
 4616: 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
 4617: 09 are not valid octal constants. Single digits will be used for minor values
 4618: less than 10.
 4619: 
 4620: 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
 4621: existing programs that set these in the POSIX interface can use PCRE without
 4622: modification.
 4623: 
 4624: 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
 4625: return all that pcre_info() returns, plus additional data. The pcre_info()
 4626: function is retained for compatibility, but is considered to be obsolete.
 4627: 
 4628: 10. Added experimental recursion feature (?R) to handle one common case that
 4629: Perl 5.6 will be able to do with (?p{...}).
 4630: 
 4631: 11. Added support for POSIX character classes like [:alpha:], which Perl is
 4632: adopting.
 4633: 
 4634: 
 4635: Version 2.08 31-Aug-99
 4636: ----------------------
 4637: 
 4638: 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
 4639: trying to match at the startoffset position, but instead was moving forward to
 4640: the next newline as if a previous match had failed.
 4641: 
 4642: 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
 4643: and could get into a loop if a null string was matched other than at the start
 4644: of the subject.
 4645: 
 4646: 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
 4647: be distinguished at compile time, and for completeness also added PCRE_DATE.
 4648: 
 4649: 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
 4650: in GnuWin32 environments.
 4651: 
 4652: 
 4653: Version 2.07 29-Jul-99
 4654: ----------------------
 4655: 
 4656: 1. The documentation is now supplied in plain text form and HTML as well as in
 4657: the form of man page sources.
 4658: 
 4659: 2. C++ compilers don't like assigning (void *) values to other pointer types.
 4660: In particular this affects malloc(). Although there is no problem in Standard
 4661: C, I've put in casts to keep C++ compilers happy.
 4662: 
 4663: 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
 4664: should be (const char *).
 4665: 
 4666: 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
 4667: be useful for non-Unix systems who don't want to bother with the POSIX stuff.
 4668: However, I haven't made this a standard facility. The documentation doesn't
 4669: mention it, and the Makefile doesn't support it.
 4670: 
 4671: 5. The Makefile now contains an "install" target, with editable destinations at
 4672: the top of the file. The pcretest program is not installed.
 4673: 
 4674: 6. pgrep -V now gives the PCRE version number and date.
 4675: 
 4676: 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
 4677: causing the entire string to be ignored, instead of just the last character.
 4678: 
 4679: 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
 4680: non-matching string, it can take a very, very long time, even for strings of
 4681: quite modest length, because of the nested recursion. PCRE now does better in
 4682: some of these cases. It does this by remembering the last required literal
 4683: character in the pattern, and pre-searching the subject to ensure it is present
 4684: before running the real match. In other words, it applies a heuristic to detect
 4685: some types of certain failure quickly, and in the above example, if presented
 4686: with a string that has no trailing " it gives "no match" very quickly.
 4687: 
 4688: 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
 4689: other alternatives are tried instead.
 4690: 
 4691: 
 4692: Version 2.06 09-Jun-99
 4693: ----------------------
 4694: 
 4695: 1. Change pcretest's output for amount of store used to show just the code
 4696: space, because the remainder (the data block) varies in size between 32-bit and
 4697: 64-bit systems.
 4698: 
 4699: 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
 4700: start matching at. This allows lookbehinds to work when searching for multiple
 4701: occurrences in a string.
 4702: 
 4703: 3. Added additional options to pcretest for testing multiple occurrences:
 4704: 
 4705:    /+   outputs the rest of the string that follows a match
 4706:    /g   loops for multiple occurrences, using the new startoffset argument
 4707:    /G   loops for multiple occurrences by passing an incremented pointer
 4708: 
 4709: 4. PCRE wasn't doing the "first character" optimization for patterns starting
 4710: with \b or \B, though it was doing it for other lookbehind assertions. That is,
 4711: it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
 4712: the letter 'x'. On long subject strings, this gives a significant speed-up.
 4713: 
 4714: 
 4715: Version 2.05 21-Apr-99
 4716: ----------------------
 4717: 
 4718: 1. Changed the type of magic_number from int to long int so that it works
 4719: properly on 16-bit systems.
 4720: 
 4721: 2. Fixed a bug which caused patterns starting with .* not to work correctly
 4722: when the subject string contained newline characters. PCRE was assuming
 4723: anchoring for such patterns in all cases, which is not correct because .* will
 4724: not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
 4725: DOTALL is set at top level; otherwise it knows that patterns starting with .*
 4726: must be retried after every newline in the subject.
 4727: 
 4728: 
 4729: Version 2.04 18-Feb-99
 4730: ----------------------
 4731: 
 4732: 1. For parenthesized subpatterns with repeats whose minimum was zero, the
 4733: computation of the store needed to hold the pattern was incorrect (too large).
 4734: If such patterns were nested a few deep, this could multiply and become a real
 4735: problem.
 4736: 
 4737: 2. Added /M option to pcretest to show the memory requirement of a specific
 4738: pattern. Made -m a synonym of -s (which does this globally) for compatibility.
 4739: 
 4740: 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
 4741: compiled in such a way that the backtracking after subsequent failure was
 4742: pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
 4743: ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
 4744: 
 4745: 
 4746: Version 2.03 02-Feb-99
 4747: ----------------------
 4748: 
 4749: 1. Fixed typo and small mistake in man page.
 4750: 
 4751: 2. Added 4th condition (GPL supersedes if conflict) and created separate
 4752: LICENCE file containing the conditions.
 4753: 
 4754: 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
 4755: Perl, that is the internal \ allows the delimiter to be included in the
 4756: pattern. Locked out the use of \ as a delimiter. If \ immediately follows
 4757: the final delimiter, add \ to the end of the pattern (to test the error).
 4758: 
 4759: 4. Added the convenience functions for extracting substrings after a successful
 4760: match. Updated pcretest to make it able to test these functions.
 4761: 
 4762: 
 4763: Version 2.02 14-Jan-99
 4764: ----------------------
 4765: 
 4766: 1. Initialized the working variables associated with each extraction so that
 4767: their saving and restoring doesn't refer to uninitialized store.
 4768: 
 4769: 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
 4770: compiler for OS/2 into generating correct code. Apparently IBM isn't going to
 4771: fix the problem.
 4772: 
 4773: 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
 4774: calls, and wasn't printing the correct value for compiling calls. Increased the
 4775: default value of LOOPREPEAT, and the number of significant figures in the
 4776: times.
 4777: 
 4778: 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
 4779: 
 4780: 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
 4781: a building problem on Windows NT with a FAT file system.
 4782: 
 4783: 
 4784: Version 2.01 21-Oct-98
 4785: ----------------------
 4786: 
 4787: 1. Changed the API for pcre_compile() to allow for the provision of a pointer
 4788: to character tables built by pcre_maketables() in the current locale. If NULL
 4789: is passed, the default tables are used.
 4790: 
 4791: 
 4792: Version 2.00 24-Sep-98
 4793: ----------------------
 4794: 
 4795: 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
 4796: it any more.
 4797: 
 4798: 2. Allow quantification of (?>) groups, and make it work correctly.
 4799: 
 4800: 3. The first character computation wasn't working for (?>) groups.
 4801: 
 4802: 4. Correct the implementation of \Z (it is permitted to match on the \n at the
 4803: end of the subject) and add 5.005's \z, which really does match only at the
 4804: very end of the subject.
 4805: 
 4806: 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
 4807: 
 4808: 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
 4809: DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
 4810: localized options. All options to pcre_study() were also removed.
 4811: 
 4812: 7. Add other new features from 5.005:
 4813: 
 4814:    $(?<=           positive lookbehind
 4815:    $(?<!           negative lookbehind
 4816:    (?imsx-imsx)    added the unsetting capability
 4817:                    such a setting is global if at outer level; local otherwise
 4818:    (?imsx-imsx:)   non-capturing groups with option setting
 4819:    (?(cond)re|re)  conditional pattern matching
 4820: 
 4821:    A backreference to itself in a repeated group matches the previous
 4822:    captured string.
 4823: 
 4824: 8. General tidying up of studying (both automatic and via "study")
 4825: consequential on the addition of new assertions.
 4826: 
 4827: 9. As in 5.005, unlimited repeated groups that could match an empty substring
 4828: are no longer faulted at compile time. Instead, the loop is forcibly broken at
 4829: runtime if any iteration does actually match an empty substring.
 4830: 
 4831: 10. Include the RunTest script in the distribution.
 4832: 
 4833: 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
 4834: discrepancies, some of which were old and were also with respect to 5.004. They
 4835: have now been fixed.
 4836: 
 4837: 
 4838: Version 1.09 28-Apr-98
 4839: ----------------------
 4840: 
 4841: 1. A negated single character class followed by a quantifier with a minimum
 4842: value of one (e.g.  [^x]{1,6}  ) was not compiled correctly. This could lead to
 4843: program crashes, or just wrong answers. This did not apply to negated classes
 4844: containing more than one character, or to minima other than one.
 4845: 
 4846: 
 4847: Version 1.08 27-Mar-98
 4848: ----------------------
 4849: 
 4850: 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
 4851: 
 4852: 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
 4853: latter must appear before anything that relies on it in the pattern.
 4854: 
 4855: 
 4856: Version 1.07 16-Feb-98
 4857: ----------------------
 4858: 
 4859: 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
 4860: repeat of a potentially empty string).
 4861: 
 4862: 
 4863: Version 1.06 23-Jan-98
 4864: ----------------------
 4865: 
 4866: 1. Added Markus Oberhumer's little patches for C++.
 4867: 
 4868: 2. Literal strings longer than 255 characters were broken.
 4869: 
 4870: 
 4871: Version 1.05 23-Dec-97
 4872: ----------------------
 4873: 
 4874: 1. Negated character classes containing more than one character were failing if
 4875: PCRE_CASELESS was set at run time.
 4876: 
 4877: 
 4878: Version 1.04 19-Dec-97
 4879: ----------------------
 4880: 
 4881: 1. Corrected the man page, where some "const" qualifiers had been omitted.
 4882: 
 4883: 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
 4884: input syntax.
 4885: 
 4886: 3. Fixed memory leak which occurred when a regex with back references was
 4887: matched with an offsets vector that wasn't big enough. The temporary memory
 4888: that is used in this case wasn't being freed if the match failed.
 4889: 
 4890: 4. Tidied pcretest to ensure it frees memory that it gets.
 4891: 
 4892: 5. Temporary memory was being obtained in the case where the passed offsets
 4893: vector was exactly big enough.
 4894: 
 4895: 6. Corrected definition of offsetof() from change 5 below.
 4896: 
 4897: 7. I had screwed up change 6 below and broken the rules for the use of
 4898: setjmp(). Now fixed.
 4899: 
 4900: 
 4901: Version 1.03 18-Dec-97
 4902: ----------------------
 4903: 
 4904: 1. A erroneous regex with a missing opening parenthesis was correctly
 4905: diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
 4906: on some systems.
 4907: 
 4908: 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
 4909: it was reported that one broken compiler failed on the former because "code" is
 4910: also an independent variable.
 4911: 
 4912: 3. The erroneous regex a[]b caused an array overrun reference.
 4913: 
 4914: 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
 4915: fail on data ending with that character. (It was going on too far, and checking
 4916: the next character, typically a binary zero.) This was specific to the
 4917: optimized code for single-character negative classes.
 4918: 
 4919: 5. Added a contributed patch from the TIN world which does the following:
 4920: 
 4921:   + Add an undef for memmove, in case the the system defines a macro for it.
 4922: 
 4923:   + Add a definition of offsetof(), in case there isn't one. (I don't know
 4924:     the reason behind this - offsetof() is part of the ANSI standard - but
 4925:     it does no harm).
 4926: 
 4927:   + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
 4928:     most of the places where whitespace preceded '#'. I have given up and
 4929:     allowed the remaining 2 cases to be at the margin.
 4930: 
 4931:   + Rename some variables in pcre to eliminate shadowing. This seems very
 4932:     pedantic, but does no harm, of course.
 4933: 
 4934: 6. Moved the call to setjmp() into its own function, to get rid of warnings
 4935: from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
 4936: 
 4937: 7. Constructs such as \d{8,} were compiling into the equivalent of
 4938: \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
 4939: outcome, but in this particular case used more store than had been allocated,
 4940: which caused the bug to be discovered because it threw up an internal error.
 4941: 
 4942: 8. The debugging code in both pcre and pcretest for outputting the compiled
 4943: form of a regex was going wrong in the case of back references followed by
 4944: curly-bracketed repeats.
 4945: 
 4946: 
 4947: Version 1.02 12-Dec-97
 4948: ----------------------
 4949: 
 4950: 1. Typos in pcre.3 and comments in the source fixed.
 4951: 
 4952: 2. Applied a contributed patch to get rid of places where it used to remove
 4953: 'const' from variables, and fixed some signed/unsigned and uninitialized
 4954: variable warnings.
 4955: 
 4956: 3. Added the "runtest" target to Makefile.
 4957: 
 4958: 4. Set default compiler flag to -O2 rather than just -O.
 4959: 
 4960: 
 4961: Version 1.01 19-Nov-97
 4962: ----------------------
 4963: 
 4964: 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
 4965: like /([ab]*)*/, that is, for classes with more than one character in them.
 4966: 
 4967: 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
 4968: as /((?>a*))*/ (a PCRE_EXTRA facility).
 4969: 
 4970: 
 4971: Version 1.00 18-Nov-97
 4972: ----------------------
 4973: 
 4974: 1. Added compile-time macros to support systems such as SunOS4 which don't have
 4975: memmove() or strerror() but have other things that can be used instead.
 4976: 
 4977: 2. Arranged that "make clean" removes the executables.
 4978: 
 4979: 
 4980: Version 0.99 27-Oct-97
 4981: ----------------------
 4982: 
 4983: 1. Fixed bug in code for optimizing classes with only one character. It was
 4984: initializing a 32-byte map regardless, which could cause it to run off the end
 4985: of the memory it had got.
 4986: 
 4987: 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
 4988: 
 4989: 
 4990: Version 0.98 22-Oct-97
 4991: ----------------------
 4992: 
 4993: 1. Fixed bug in code for handling temporary memory usage when there are more
 4994: back references than supplied space in the ovector. This could cause segfaults.
 4995: 
 4996: 
 4997: Version 0.97 21-Oct-97
 4998: ----------------------
 4999: 
 5000: 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
 5001: 
 5002: 2. Optimized negated single characters not to use a bit map.
 5003: 
 5004: 3. Brought error texts together as macro definitions; clarified some of them;
 5005: fixed one that was wrong - it said "range out of order" when it meant "invalid
 5006: escape sequence".
 5007: 
 5008: 4. Changed some char * arguments to const char *.
 5009: 
 5010: 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
 5011: 
 5012: 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
 5013: pcretest.
 5014: 
 5015: 
 5016: Version 0.96 16-Oct-97
 5017: ----------------------
 5018: 
 5019: 1. Added a simple "pgrep" utility to the distribution.
 5020: 
 5021: 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
 5022: unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
 5023: where "ddd" means "one or more decimal digits".
 5024: 
 5025: 3. Fixed serious bug. If a pattern had a back reference, but the call to
 5026: pcre_exec() didn't supply a large enough ovector to record the related
 5027: identifying subpattern, the match always failed. PCRE now remembers the number
 5028: of the largest back reference, and gets some temporary memory in which to save
 5029: the offsets during matching if necessary, in order to ensure that
 5030: backreferences always work.
 5031: 
 5032: 4. Increased the compatibility with Perl in a number of ways:
 5033: 
 5034:   (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
 5035:       to request this handling. The option can be set at compile or exec time.
 5036: 
 5037:   (b) $ matches before a terminating newline by default; an option
 5038:       PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
 5039:       mode). The option can be set at compile or exec time.
 5040: 
 5041:   (c) The handling of \ followed by a digit other than 0 is now supposed to be
 5042:       the same as Perl's. If the decimal number it represents is less than 10
 5043:       or there aren't that many previous left capturing parentheses, an octal
 5044:       escape is read. Inside a character class, it's always an octal escape,
 5045:       even if it is a single digit.
 5046: 
 5047:   (d) An escaped but undefined alphabetic character is taken as a literal,
 5048:       unless PCRE_EXTRA is set. Currently this just reserves the remaining
 5049:       escapes.
 5050: 
 5051:   (e) {0} is now permitted. (The previous item is removed from the compiled
 5052:       pattern).
 5053: 
 5054: 5. Changed all the names of code files so that the basic parts are no longer
 5055: than 10 characters, and abolished the teeny "globals.c" file.
 5056: 
 5057: 6. Changed the handling of character classes; they are now done with a 32-byte
 5058: bit map always.
 5059: 
 5060: 7. Added the -d and /D options to pcretest to make it possible to look at the
 5061: internals of compilation without having to recompile pcre.
 5062: 
 5063: 
 5064: Version 0.95 23-Sep-97
 5065: ----------------------
 5066: 
 5067: 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
 5068: \x20 at the start of a run of normal characters. These were being treated as
 5069: real characters, instead of the source characters being re-checked.
 5070: 
 5071: 
 5072: Version 0.94 18-Sep-97
 5073: ----------------------
 5074: 
 5075: 1. The functions are now thread-safe, with the caveat that the global variables
 5076: containing pointers to malloc() and free() or alternative functions are the
 5077: same for all threads.
 5078: 
 5079: 2. Get pcre_study() to generate a bitmap of initial characters for non-
 5080: anchored patterns when this is possible, and use it if passed to pcre_exec().
 5081: 
 5082: 
 5083: Version 0.93 15-Sep-97
 5084: ----------------------
 5085: 
 5086: 1. /(b)|(:+)/ was computing an incorrect first character.
 5087: 
 5088: 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
 5089: but not actually doing anything yet.
 5090: 
 5091: 3. Treat "-" characters in classes that cannot be part of ranges as literals,
 5092: as Perl does (e.g. [-az] or [az-]).
 5093: 
 5094: 4. Set the anchored flag if a branch starts with .* or .*? because that tests
 5095: all possible positions.
 5096: 
 5097: 5. Split up into different modules to avoid including unneeded functions in a
 5098: compiled binary. However, compile and exec are still in one module. The "study"
 5099: function is split off.
 5100: 
 5101: 6. The character tables are now in a separate module whose source is generated
 5102: by an auxiliary program - but can then be edited by hand if required. There are
 5103: now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
 5104: toupper() in the code.
 5105: 
 5106: 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
 5107: make them global. Abolish the function for setting them, as the caller can now
 5108: set them directly.
 5109: 
 5110: 
 5111: Version 0.92 11-Sep-97
 5112: ----------------------
 5113: 
 5114: 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
 5115: (e.g. /a{1,3}/) was broken (I mis-optimized it).
 5116: 
 5117: 2. Caseless matching was not working in character classes if the characters in
 5118: the pattern were in upper case.
 5119: 
 5120: 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
 5121: 
 5122: 4. Make PCRE_ANCHORED public and accept as a compile option.
 5123: 
 5124: 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
 5125: PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
 5126: pass them.
 5127: 
 5128: 6. Give an error if bad option bits passed at compile or run time.
 5129: 
 5130: 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
 5131: pcretest to cause it to pass that flag.
 5132: 
 5133: 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
 5134: options, and the first character, if set.
 5135: 
 5136: 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
 5137: 
 5138: 
 5139: Version 0.91 10-Sep-97
 5140: ----------------------
 5141: 
 5142: 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
 5143: match the empty string as in /(a*)*/. It was looping and ultimately crashing.
 5144: 
 5145: 2. PCRE was looping on encountering an indefinitely repeated back reference to
 5146: a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
 5147: Perl does - treats the match as successful.
 5148: 
 5149: ****