compiz crashed with SIGSEGV in PluginClassHandler<UnityWindow, CompWindow, 0>::get()

[Anders Feder]

Crashed when Alt+F4'ing window simultatenously being previewed in tab switcher.

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: unity 4.12.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.0.0-10.16-generic 3.0.4
Uname: Linux 3.0.0-10-generic x86_64
Architecture: amd64
Date: Sun Sep 4 16:19:40 2011
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
ProcCmdline: compiz --replace
ProcCwd: /home/afeder
SegvAnalysis:
 Segfault happened at: 0x7fbf52e3533a <_ZN18PluginClassHandlerI11UnityWindow10CompWindowLi0EE3getEPS1_+378>: mov 0x30(%r12),%rax
 PC (0x7fbf52e3533a) ok
 source "0x30(%r12)" (0x00000030) not located in a known VMA region (needed readable region)!
 destination "%rax" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 PluginClassHandler<UnityWindow, CompWindow, 0>::get(CompWindow*) () from /usr/lib/compiz/libunityshell.so
 UnityScreen::paintDisplay(CompRegion const&, GLMatrix const&, unsigned int) () from /usr/lib/compiz/libunityshell.so
 UnityWindow::glDraw(GLMatrix const&, GLFragment::Attrib&, CompRegion const&, unsigned int) () from /usr/lib/compiz/libunityshell.so
 GLWindow::glDraw(GLMatrix const&, GLFragment::Attrib&, CompRegion const&, unsigned int) () from /usr/lib/compiz/libopengl.so
 GLWindow::glPaint(GLWindowPaintAttrib const&, GLMatrix const&, CompRegion const&, unsigned int) () from /usr/lib/compiz/libopengl.so
Title: compiz crashed with SIGSEGV in PluginClassHandler<UnityWindow, CompWindow, 0>::get()
UpgradeStatus: Upgraded to oneiric on 2011-09-02 (2 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make Ubuntu better. This particular crash has already been reported and is a duplicate of bug #832979, 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.