sips: fix non-read messages at shutdown

Force received messages to be handled by application
before handling disconnected state event.
This fixed some later call failure event as SIP bye message
is read after the transport shutdown (causing failure).

Change-Id: I269c364927ad301cc6e067b582174e488bebd519
Tuleap: #466

src/ringdht/sips_transport_ice.cpp

@@ -279,18 +279,31 @@ void
 SipsIceTransport::handleEvents()
 {
     // Notify transport manager about state changes first
+    // Note: stop when disconnected event is encountered
+    // and differ its notification AFTER pending rx msg to let
+    // them a chance to be delivered to application before closing
+    // the transport.
     decltype(stateChangeEvents_) eventDataQueue;
     {
         std::lock_guard<std::mutex> lk{stateChangeEventsMutex_};
         eventDataQueue = std::move(stateChangeEvents_);
         stateChangeEvents_.clear();
     }
 
-    if (auto state_cb = pjsip_tpmgr_get_state_cb(trData_.base.tpmgr)) {
+    ChangeStateEventData disconnectedEvent;
+    bool disconnected = false;
+    auto state_cb = pjsip_tpmgr_get_state_cb(trData_.base.tpmgr);
+    if (state_cb) {
         for (auto& evdata : eventDataQueue) {
             evdata.tls_info.ssl_sock_info = &evdata.ssl_info;
             evdata.state_info.ext_info = &evdata.tls_info;
-            (*state_cb)(&trData_.base, evdata.state, &evdata.state_info);
+            if (evdata.state != PJSIP_TP_STATE_DISCONNECTED) {
+                (*state_cb)(&trData_.base, evdata.state, &evdata.state_info);
+            } else {
+                disconnectedEvent = std::move(evdata);
+                disconnected = true;
+                break;
+            }
         }
     }
 
@@ -328,6 +341,10 @@ SipsIceTransport::handleEvents()
             }
         }
     }
+
+    // Time to deliver disconnected event if exists
+    if (disconnected and state_cb)
+        (*state_cb)(&trData_.base, disconnectedEvent.state, &disconnectedEvent.state_info);
 }
 
 void