--- libaitmqtt/src/pub.c	2012/04/27 15:49:07	1.1.1.1.2.4
+++ libaitmqtt/src/pub.c	2012/06/21 13:47:30	1.2.2.1
@@ -3,7 +3,7 @@
 *  by Michael Pounov <misho@openbsd-bg.org>
 *
 * $Author: misho $
-* $Id: pub.c,v 1.1.1.1.2.4 2012/04/27 15:49:07 misho Exp $
+* $Id: pub.c,v 1.2.2.1 2012/06/21 13:47:30 misho Exp $
 *
 **************************************************************************
 The ELWIX and AITNET software is distributed under the following
@@ -63,7 +63,8 @@ int
 mqtt_msgPUBLISH(mqtt_msg_t * __restrict buf, const char *csTopic, u_short msgID, 
 		u_char Dup, u_char QOS, u_char Retain, const void *pData, int datlen)
 {
-	int siz = 0;
+	int len, siz;
+	u_int n, *l;
 	struct mqtthdr *hdr;
 	mqtthdr_var_t *topic;
 	mqtt_len_t *mid;
@@ -80,39 +81,48 @@ mqtt_msgPUBLISH(mqtt_msg_t * __restrict buf, const cha
 		return -1;
 	}
 
-	if (mqtt_msgRealloc(buf, MQTTMSG_MAX) == -1)
+	/* calculate message size */
+	len = sizeof(mqtt_len_t) + strlen(csTopic);	/* topic */
+	len += sizeof(mqtt_len_t);			/* msgid */
+	len += datlen;					/* data len */
+
+	/* calculate header size */
+	siz = sizeof(struct mqtthdr);			/* mqtt fixed header */
+	n = mqtt_encodeLen(len);			/* message size */
+	siz += mqtt_sizeLen(n) - 1;			/* length size */
+
+	if (mqtt_msgRealloc(buf, siz + len) == -1)
 		return -1;
 	else {
-		hdr = (struct mqtthdr *) (buf->msg_base + siz);
-		siz += sizeof(struct mqtthdr);
+		data = buf->msg_base;
+		hdr = (struct mqtthdr *) data;
 	}
 
+	/* fixed header */
+	MQTTHDR_MSGINIT(hdr);
+	hdr->mqtt_msg.type = MQTT_TYPE_PUBLISH;
+	hdr->mqtt_msg.qos = QOS;
+	hdr->mqtt_msg.dup = Dup ? 1 : 0;
+	hdr->mqtt_msg.retain = Retain ? 1 : 0;
+	l = (u_int*) hdr->mqtt_len;
+	*l = n;
+	data += siz;
+
 	/* variable header */
-	topic = (mqtthdr_var_t*) (buf->msg_base + siz);
+	topic = (mqtthdr_var_t*) data;
 	topic->var_sb.val = htons(strlen(csTopic));
 	memcpy(topic->var_data, csTopic, ntohs(topic->var_sb.val));
-	siz += MQTTHDR_VAR_SIZEOF(topic);
+	data += MQTTHDR_VAR_SIZEOF(topic);
 
-	mid = (mqtt_len_t*) (buf->msg_base + siz);
+	mid = (mqtt_len_t*) data;
 	mid->val = htons(msgID);
-	siz += sizeof(mqtt_len_t);
+	data += sizeof(mqtt_len_t);
 
 	/* load with data */
-	if (pData && datlen) {
-		data = buf->msg_base + siz;
+	if (pData && datlen)
 		memcpy(data, pData, datlen);
-		siz += datlen;
-	}
 
-	/* fixed header */
-	MQTTHDR_MSGINIT(hdr);
-	hdr->mqtt_msg.type = MQTT_TYPE_PUBLISH;
-	hdr->mqtt_msg.qos = QOS;
-	hdr->mqtt_msg.dup = Dup ? 1 : 0;
-	hdr->mqtt_msg.retain = Retain ? 1 : 0;
-	*hdr->mqtt_len = mqtt_encodeLen(siz - sizeof(struct mqtthdr));
-
-	return siz;
+	return siz + len;
 }
 
 static int
@@ -207,7 +217,7 @@ mqtt_msgPUBCOMP(mqtt_msg_t * __restrict buf, u_short m
  * @psTopic = Topic
  * @topicLen = Topic length
  * @msgID = MessageID
- * @pData = Data buffer
+ * @pData = Data buffer, may be NULL
  * return: -1 error or !=-1 allocated data buffer length
  */
 int
@@ -220,7 +230,7 @@ mqtt_readPUBLISH(mqtt_msg_t * __restrict buf, char * _
 	mqtt_len_t *v;
 	caddr_t pos;
 
-	if (!buf || !psTopic || !msgID || !pData)
+	if (!buf || !psTopic || !msgID)
 		return -1;
 
 	hdr = _mqtt_readHEADER(buf, MQTT_TYPE_PUBLISH, &ret, &len);
@@ -255,7 +265,7 @@ mqtt_readPUBLISH(mqtt_msg_t * __restrict buf, char * _
 	if (len < 0) {
 		mqtt_SetErr(EINVAL, "Short message length %d", len);
 		return -1;
-	} else {
+	} else if (pData) {
 		if (!(*pData = malloc(len + 1))) {
 			LOGERR;
 			return -1;