Crash in mir::scene::ApplicationSession::name (this=<optimized out>) at /build/mir-xon0uu/mir-0.14.1+15.04.20150821/src/server/scene/application_session.cpp:237

[errors.ubuntu.com bug bridge]

The Ubuntu Error Tracker has been receiving reports about a problem regarding unity8. This problem was most recently seen with version 8.11+15.04.20150831.2-0ubuntu1, the problem page at https://errors.ubuntu.com/problem/991b418fa265212ec607fdb9a7ab715d6e60bbc2 contains more details.

[Albert Astals Cid (aacid)]

Something (mir? qtmir?) is asking for a string of __capacity=2899393464 (probably already deleted data?)

[Daniel van Vugt (vanvugt)]

Seems to be a fairly obvious mistake in Mir. We're sharing a cons reference to an object that may not exist:

    ApplicationSession(
        std::shared_ptr<SurfaceCoordinator> const& surface_coordinator,
        std::shared_ptr<SurfaceFactory> const& surface_factory,
        std::shared_ptr<BufferStreamFactory> const& buffer_stream_factory,
        pid_t pid,
        std::string const& session_name, <----------- HERE
        std::shared_ptr<SnapshotStrategy> const& snapshot_strategy,
        std::shared_ptr<SessionListener> const& session_listener,
        std::shared_ptr<frontend::EventSink> const& sink);

[Daniel van Vugt (vanvugt)]

Whoops. It's not a reference. But still might be due to some std::string optimization (COW) ?...
    std::string const session_name;

[Daniel van Vugt (vanvugt)]

Or we're perhaps trying to get the name of an ApplicationSession object that no longer exists.

[Cemil Azizoglu (cemil-azizoglu)]

This bug hasn't been encountered for about 2 months. Looking at the stack trace, it seems to me that qtmir is accessing 'name' member of a session that's already been destroyed, from the onSessionDestroyingSurface function. I don't think this is a problem in Mir, but may still be a problem in qtmir, though it may have been masked by code changes since around the last time this was seen.