Media-hub fails to get the call started/ended signals from telepathy-bridge

If using RTM, you can easily reproduce the bug using the packages available at http://people.canonical.com/~rsalveti/boiko/ (including some extra debugging messages).

Check the log that is available at /home/phablet/.cache/upstart/media-hub.log when play an audio and calling your phone.

When it works, you should get the following:
Got call started signal, pausing all multimedia sessions
Pausing Player with key: 0
pause

After adding some debug lines, the problem is that sometimes there is no audiocalls or videocalls caps when starting media-hub, so it never really connects the off/on hook signals.

150 void checkAndAddAccount(const Tp::AccountPtr& account)
151 {
152 Tp::ConnectionCapabilities caps = account->capabilities();
153
154 // anything call like, perhaps overkill?
155 if (caps.audioCalls() || caps.videoCalls() || caps.videoCallsWithAudio() || caps.streamedMediaCalls()) {
156 auto tcm = new TelepathyCallMonitor(account);
157 connect(tcm, SIGNAL(offHook()), SLOT(offHook()));
158 connect(tcm, SIGNAL(onHook()), SLOT(onHook()));
159 mCallMonitors.push_back(tcm);
160 }
161 }

Added a debug line in order to get the connection status (account->connection()->status()), and was able to get a crash when I reproduced this issue:
#0 0xb6b2e27c in Tp::Connection::status() const () from /usr/lib/arm-linux-gnueabihf/libtelepathy-qt5.so.0
No symbol table info available.
#1 0x0014ec44 in ?? ()
No symbol table info available.
#2 0xb68140e4 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5
No symbol table info available.
#3 0xb6beb60c in Tp::PendingOperation::finished(Tp::PendingOperation*) () from /usr/lib/arm-linux-gnueabihf/libtelepathy-qt5.so.0
No symbol table info available.
#4 0xb6bed286 in ?? () from /usr/lib/arm-linux-gnueabihf/libtelepathy-qt5.so.0
No symbol table info available.
#5 0xb6814b60 in QObject::event(QEvent*) () from /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5

Which means the connection is probably not fully up at that stage.

This bug was fixed in the package media-hub - 2.0.0+15.04.20150112.2-0ubuntu1

---------------
media-hub (2.0.0+15.04.20150112.2-0ubuntu1) vivid; urgency=low

  [ Ubuntu daily release ]
  * New rebuild forced

  [ Ricardo Salveti de Araujo ]
  * service_implementation: adding debug for call started/ended signals.
    Make sure account and connection are available when setting up
    account manager (patch from Gustavo Boiko). call_monitor: don't
    check caps when hooking up on/off signals, until bug 1409125 is
    fixed. Enable parallel building . (LP: #1409125)
 -- Ubuntu daily release <email address hidden> Mon, 12 Jan 2015 21:38:39 +0000

Reopening as we pushed a workaround instead.