compiz crashed with SIGSEGV in empty() (unity::ui::PointerBarrierWrapper::EmitCurrentData)

[GodNobody]

happend after unplugging the external screen

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: unity 5.6.0-0ubuntu4
ProcVersionSignature: Ubuntu 3.2.0-18.29-generic 3.2.9
Uname: Linux 3.2.0-18-generic x86_64
ApportVersion: 1.94.1-0ubuntu2
Architecture: amd64
Date: Sat Mar 17 20:21:29 2012
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120303)
ProcCmdline: compiz
SegvAnalysis:
 Segfault happened at: 0x7fd88f335cd9 <_ZN5unity2ui21PointerBarrierWrapper15EmitCurrentDataEv+393>: mov 0x8(%rdi),%rax
 PC (0x7fd88f335cd9) ok
 source "0x8(%rdi)" (0x3030303030303038) not located in a known VMA region (needed readable region)!
 destination "%rax" ok
SegvReason: reading unknown VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 unity::ui::PointerBarrierWrapper::EmitCurrentData() () from /usr/lib/compiz/libunityshell.so
 ?? () from /usr/lib/compiz/libunityshell.so
 ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
 g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
 ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
Title: compiz crashed with SIGSEGV in unity::ui::PointerBarrierWrapper::EmitCurrentData()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo vboxusers

[Apport retracing service (apport)]

StacktraceTop:
 empty (this=<optimized out>) at /usr/include/sigc++-2.0/sigc++/functors/slot_base.h:273
 emit (_A_a2=..., _A_a1=@0x7fff7e9093d8, impl=<optimized out>) at /usr/include/sigc++-2.0/sigc++/signal.h:1250
 emit (_A_a2=..., _A_a1=@0x7fff7e9093d8, this=<optimized out>) at /usr/include/sigc++-2.0/sigc++/signal.h:2891
 unity::ui::PointerBarrierWrapper::EmitCurrentData (this=0x27e40d0) at /build/buildd/unity-5.6.0/plugins/unityshell/src/PointerBarrier.cpp:121
 operator() (user_data=0x27e40d0, this=<optimized out>) at /build/buildd/unity-5.6.0/plugins/unityshell/src/PointerBarrier.cpp:146

[Launchpad Janitor (janitor)]

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

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 983268, so it 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. Feel free to continue to report any other bugs you may find.