Few minor transfer tweaks. We can't unlock something we never locked, and better handle a specific scenario with doing an attended transfer between two non-bridged calls.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@69661 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -12918,7 +12918,7 @@ static int attempt_transfer(struct sip_dual *transferer, struct sip_dual *target
 			ast_softhangup_nolock(transferer->chan1, AST_SOFTHANGUP_DEV);
 		if (target->chan1)
 			ast_softhangup_nolock(target->chan1, AST_SOFTHANGUP_DEV);
-		return -1;
+		return -2;
 	}
 	return 0;
 }
@@ -13864,7 +13864,8 @@ static int local_attended_transfer(struct sip_pvt *transferer, struct sip_dual *
 		if (targetcall_pvt->owner)
 			ast_channel_unlock(targetcall_pvt->owner);
 		/* Right now, we have to hangup, sorry. Bridge is destroyed */
-		ast_hangup(transferer->owner);
+		if (res != -2)
+			ast_hangup(transferer->owner);
 	} else {
 		/* Transfer succeeded! */
 
@@ -14157,7 +14158,6 @@ static int handle_request_refer(struct sip_pvt *p, struct sip_request *req, int
     	   be accessible after the transfer! */
 	*nounlock = 1;
 	ast_channel_unlock(current.chan1);
-	ast_channel_unlock(current.chan2);
 
 	/* Connect the call */