gnome-shell crashed with SIGABRT in g_assertion_message()

[Luke Faraone]

Occurred with Firefox in full-screen, while in a modal (which hid the main browser window)

ProblemType: Crash
DistroRelease: Ubuntu 14.10
Package: gnome-shell 3.12.2-1ubuntu7
ProcVersionSignature: Ubuntu 3.16.0-29.39-generic 3.16.7-ckt2
Uname: Linux 3.16.0-29-generic x86_64
NonfreeKernelModules: openafs
ApportVersion: 2.14.7-0ubuntu8
Architecture: amd64
CurrentDesktop: GNOME
Date: Sun Jan 18 20:55:58 2015
DisplayManager: gdm
ExecutablePath: /usr/bin/gnome-shell
InstallationDate: Installed on 2013-03-18 (672 days ago)
InstallationMedia: Ubuntu 12.04.2 LTS "Precise Pangolin" - Release amd64 (20130214)
ProcCmdline: /usr/bin/gnome-shell
Signal: 6
SourcePackage: gnome-shell
StacktraceTop:
 g_assertion_message () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
 g_assertion_message_expr () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
 meta_window_unmanage () from /usr/lib/libmutter.so.0
 ?? () from /usr/lib/libmutter.so.0
 ?? () from /usr/lib/libmutter.so.0
Title: gnome-shell crashed with SIGABRT in g_assertion_message()
UpgradeStatus: Upgraded to utopic on 2014-10-27 (84 days ago)
UserGroups: adm cdrom dip fuse kvm libvirtd lpadmin netdev plugdev sambashare sbuild sudo

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #1351011, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.