--- embedaddon/libiconv/srcm4/setenv.m4	2012/05/29 09:29:44	1.1.1.2
+++ embedaddon/libiconv/srcm4/setenv.m4	2021/03/17 13:38:46	1.1.1.3
@@ -1,5 +1,5 @@
-# setenv.m4 serial 24
-dnl Copyright (C) 2001-2004, 2006-2011 Free Software Foundation, Inc.
+# setenv.m4 serial 28
+dnl Copyright (C) 2001-2004, 2006-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -7,6 +7,7 @@ dnl with or without modifications, as long as this not
 AC_DEFUN([gl_FUNC_SETENV],
 [
   AC_REQUIRE([gl_FUNC_SETENV_SEPARATE])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   if test $ac_cv_func_setenv = no; then
     HAVE_SETENV=0
   else
@@ -33,10 +34,21 @@ AC_DEFUN([gl_FUNC_SETENV],
        return result;
       ]])],
       [gl_cv_func_setenv_works=yes], [gl_cv_func_setenv_works=no],
-      [gl_cv_func_setenv_works="guessing no"])])
-    if test "$gl_cv_func_setenv_works" != yes; then
-      REPLACE_SETENV=1
-    fi
+      [case "$host_os" in
+                        # Guess yes on glibc systems.
+         *-gnu* | gnu*) gl_cv_func_setenv_works="guessing yes" ;;
+                        # Guess yes on musl systems.
+         *-musl*)       gl_cv_func_setenv_works="guessing yes" ;;
+                        # If we don't know, assume the worst.
+         *)             gl_cv_func_setenv_works="guessing no" ;;
+       esac
+      ])])
+    case "$gl_cv_func_setenv_works" in
+      *yes) ;;
+      *)
+        REPLACE_SETENV=1
+        ;;
+    esac
   fi
 ])
 
@@ -56,6 +68,7 @@ AC_DEFUN([gl_FUNC_SETENV_SEPARATE],
 AC_DEFUN([gl_FUNC_UNSETENV],
 [
   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CHECK_DECLS_ONCE([unsetenv])
   if test $ac_cv_have_decl_unsetenv = no; then
     HAVE_DECL_UNSETENV=0
@@ -77,11 +90,7 @@ extern
 #ifdef __cplusplus
 "C"
 #endif
-#if defined(__STDC__) || defined(__cplusplus)
 int unsetenv (const char *name);
-#else
-int unsetenv();
-#endif
             ]],
             [[]])],
          [gt_cv_func_unsetenv_ret='int'],
@@ -119,10 +128,19 @@ int unsetenv();
        if (getenv ("a")) return 6;
       ]])],
       [gl_cv_func_unsetenv_works=yes], [gl_cv_func_unsetenv_works=no],
-      [gl_cv_func_unsetenv_works="guessing no"])])
-    if test "$gl_cv_func_unsetenv_works" != yes; then
-      REPLACE_UNSETENV=1
-    fi
+      [case "$host_os" in
+                 # Guess yes on glibc systems.
+         *-gnu*) gl_cv_func_unsetenv_works="guessing yes" ;;
+                 # If we don't know, assume the worst.
+         *)      gl_cv_func_unsetenv_works="guessing no" ;;
+       esac
+      ])])
+    case "$gl_cv_func_unsetenv_works" in
+      *yes) ;;
+      *)
+        REPLACE_UNSETENV=1
+        ;;
+    esac
   fi
 ])