Reverted modutil_get_complete_packets changes

The changes caused the binlogrouter to malfunction.

server/core/modutil.c

@@ -558,54 +558,65 @@ return_packetbuf:
  * @param p_readbuf Buffer to split, set to NULL if no partial packets are left
  * @return Head of the chain of complete packets, all in a single, contiguous buffer
  */
-GWBUF* modutil_get_complete_packets(GWBUF **p_readbuf)
+GWBUF* modutil_get_complete_packets(GWBUF** p_readbuf)
 {
-    GWBUF *complete_part = NULL;
+    GWBUF *buff = NULL, *packet;
     uint8_t *ptr;
-    uint32_t len, blen, total = 0;
+    uint32_t len,blen,total = 0;
 
-    /** Give up if the parameter is not a pointer to a pointer or
-     * the total buffer length is less than the 3 bytes needed to
-     * hold a packet length. */
     if (p_readbuf == NULL || (*p_readbuf) == NULL ||
-       (blen = gwbuf_length(*p_readbuf)) < 3)
+       gwbuf_length(*p_readbuf) < 3)
     {
         return NULL;
     }
 
-    *p_readbuf = gwbuf_make_contiguous(*p_readbuf);
-    ptr = (uint8_t*)(*p_readbuf)->start;
+    packet = gwbuf_make_contiguous(*p_readbuf);
+    packet->next = NULL;
+    *p_readbuf = packet;
+    ptr = (uint8_t*)packet->start;
+    len = gw_mysql_get_byte3(ptr) + 4;
+    blen = gwbuf_length(packet);
 
-    /** We need at least 3 bytes of the packet header to know how long the next
-     * packet is going to be, if we are going to cycle round again. */
-    while (total + (len = gw_mysql_get_byte3(ptr) + 4) < (blen - 3))
+    if (len == blen)
+    {
+        *p_readbuf = NULL;
+        return packet;
+    }
+    else if (len > blen)
+    {
+        return NULL;
+    }
+
+    while (total + len < blen)
     {
         ptr += len;
         total += len;
+
+        /** We need at least 3 bytes of the packet header to know how long the whole
+         * packet is going to be. */
+        if (total + 3 >= blen)
+        {
+            break;
+        }
+
+        len = gw_mysql_get_byte3(ptr) + 4;
     }
 
-    total += len;
-    /* If total has overshot the buffer(s) return null, this is an error. */
-    if (total > blen)
+    /** Full packets only, return original */
+    if (total + len == blen)
     {
-        return NULL;
-    }
-    /** Full packets only, return original and null the passed buffer */
-    if (total == blen)
-    {
-        GWBUF *packet = *p_readbuf;
         *p_readbuf = NULL;
         return packet;
     }
 
     /** The next packet is a partial, split into complete and partial packets */
-    if ((complete_part = gwbuf_clone_portion(*p_readbuf, 0, total)) == NULL)
+    if ((buff = gwbuf_clone_portion(packet, 0, total)) == NULL)
     {
-        MXS_ERROR("Failed to partially clone buffer while extracting complete packets.");
+        MXS_ERROR("Failed to partially clone buffer.");
         return NULL;
     }
-    *p_readbuf = gwbuf_consume(*p_readbuf, total);
-    return complete_part;
+    gwbuf_consume(packet,total);
+    return buff;
 }
 
 /**