Unity8 crashes and restarts when clicking on a menu [terminate called after throwing an instance of 'std::out_of_range' what(): map::at]

Might be related to bug 1497128?

Status changed to 'Confirmed' because the bug affects multiple users.

The tracetop suggests this might be dupe of bug #1643976 - although not sure where we'd be instantiating a WebView in this case...

I'm not sure exactly what is happening, but I suspect is needs something like the following in some other method. (from lp:qtmir src/platforms/mirserver/windowmanagementpolicy.cpp):

void WindowManagementPolicy::resize(const miral::Window &window, const Size size)
{
    miral::WindowSpecification modifications;
    modifications.size() = size;
    m_tools.invoke_under_lock([&window, &modifications, this]() {
        try {
            m_tools.modify_window(m_tools.info_for(window), modifications);
        } catch (const std::out_of_range&) {
            // usually shell trying to operate on a window which already closed, just ignore
            // TODO: MirSurface extends the miral::Window lifetime by holding a shared pointer to
            // the mir::scene::Surface, meaning it cannot detect when the window has been closed
            // and thus avoid calling this method.
        }
    });
}

This bug was fixed in the package unity8 - 8.15+17.04.20170206-0ubuntu1

---------------
unity8 (8.15+17.04.20170206-0ubuntu1) zesty; urgency=medium

  [ Daniel d'Andrada ]
  * Initial support for child windows (menus, dialogs, tooltips) (LP:
    #1543467, #1591384, #1656727)

 -- Albert Astals Cid <email address hidden> Mon, 06 Feb 2017 09:12:23 +0000

i'm pretty sure this is fixed, i basically tested this scenario last week with no issues.

It's not fixed - I recently reproduced it using mir-demos alone.

This is an old bug, we've been hitting occasionally for a couple of years.

Sorry, both statements are true.

Aisleriot may well be fixed but the underlying Mir server crash remains. I logged that more recently as bug 1668466 that should stay open.

No, the exception was thrown by libmiral code [miral::BasicWindowManager::info_for()] and caused by synchronisation issues in QtMir code that have been worked around.

Neither the libmiral nor the QtMir code in question is involved in any of the mir-demos.