Fixes thread blocking issue in the sip TCP/TLS implementation.

(closes issue #18497)
Reported by: vois
Patches:
      issues_18497.diff uploaded by dvossel (license 671)
Tested by: vois, rossbeer, kowalma, Freddi_Fonet



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.2@309083 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -3061,14 +3061,15 @@ static void *_sip_tcp_helper_thread(struct sip_pvt *pvt, struct ast_tcptls_sessi
 				ao2_lock(me);
 				if (!(packet = AST_LIST_REMOVE_HEAD(&me->packet_q, entry))) {
 					ast_log(LOG_WARNING, "TCPTLS thread alert_pipe indicated packet should be sent, but frame_q is empty");
-				} else if (ast_tcptls_server_write(tcptls_session, ast_str_buffer(packet->data), packet->len) == -1) {
-					ast_log(LOG_WARNING, "Failure to write to tcp/tls socket\n");
 				}
+				ao2_unlock(me);
 
 				if (packet) {
+					if (ast_tcptls_server_write(tcptls_session, ast_str_buffer(packet->data), packet->len) == -1) {
+						ast_log(LOG_WARNING, "Failure to write to tcp/tls socket\n");
+					}
 					ao2_t_ref(packet, -1, "tcptls packet sent, this is no longer needed");
 				}
-				ao2_unlock(me);
 				break;
 			default:
 				ast_log(LOG_ERROR, "Unknown tcptls thread alert '%d'\n", alert);