compiz crashed with SIGSEGV in unity::ui::EdgeBarrierController::Impl::OnPointerBarrierEvent()

[Martin Yrjölä]

Compiz crashed shortly after adding a new monitor via VGA. I think the crash happened exactly when trying to move a window.

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: unity 5.10.0-0ubuntu5
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14
Uname: Linux 3.2.0-23-generic x86_64
ApportVersion: 2.0.1-0ubuntu4
Architecture: amd64
CrashCounter: 1
Date: Wed Apr 18 12:47:18 2012
Disassembly: => 0x0: Cannot access memory at address 0x0
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120201.1)
ProcCmdline: compiz
SegvAnalysis:
 Segfault happened at: 0x0: Cannot access memory at address 0x0
 PC (0x00000000) not located in a known VMA region (needed executable region)!
SegvReason: executing NULL VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 ?? ()
 unity::switcher::SwitcherView::GetBackgroundGeometry() () from /usr/lib/compiz/libunityshell.so
 ?? ()
 ?? ()
 ?? ()
Title: compiz crashed with SIGSEGV in unity::switcher::SwitcherView::GetBackgroundGeometry()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm androiddev cdrom dip lpadmin plugdev sambashare sudo

[Apport retracing service (apport)]

StacktraceTop:
 ?? ()
 unity::ui::EdgeBarrierController::Impl::OnPointerBarrierEvent (this=0x18172e0, owner=0x2c4d700, event=...) at /build/buildd/unity-5.10.0/plugins/unityshell/src/EdgeBarrierController.cpp:139
 operator() (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>) at /usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1917
 operator()<unity::ui::PointerBarrierWrapper* const&, const std::shared_ptr<unity::ui::BarrierEvent>&> (_A_arg2=<optimized out>, _A_arg1=<optimized out>, this=<optimized out>) at /usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:103
 sigc::internal::slot_call2<sigc::bound_mem_functor2<void, unity::ui::EdgeBarrierController::Impl, unity::ui::PointerBarrierWrapper*, std::shared_ptr<unity::ui::BarrierEvent> >, void, unity::ui::PointerBarrierWrapper*, std::shared_ptr<unity::ui::BarrierEvent> >::call_it (rep=<optimized out>, a_1=<optimized out>, a_2=<optimized out>) at /usr/include/sigc++-2.0/sigc++/functors/slot.h:173