It is possible for a transfer to occur before the remote device has our tag in which case they send none in the transfer. In this case we need to not fail the transfer dialog lookup.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@78182 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -8712,7 +8712,7 @@ static struct sip_pvt *get_sip_pvt_byid_locked(const char *callid, const char *t
 			   (With a forking SIP proxy, several call legs share the
 			   call id, but have different tags)
 			*/
-			if (pedanticsipchecking && (strcmp(fromtag, sip_pvt_ptr->theirtag) || strcmp(totag, ourtag)))
+			if (pedanticsipchecking && (strcmp(fromtag, sip_pvt_ptr->theirtag) || (!ast_strlen_zero(totag) && strcmp(totag, ourtag))))
 				match = 0;
 
 			if (!match) {