Application: kwin (4.6.1 (4.6.1))
KDE Platform Version: 4.6.1 (4.6.1)
Qt Version: 4.7.2
Operating System: Linux 2.6.38-2-amd64 x86_64
Distribution: Debian GNU/Linux unstable (sid)

-- Information about the crash:
- What I was doing when the application crashed:

1. second monitor was connected via HDMI and 2-screen configuration was set up via System Settings
2. I had a window on the HDMI screen (Firefox with a fullscreen Flash video).
2. I had a mouse on the second screen when I've disconnected HDMI.
3. Maybe dialog about monitor disconnect (offering to either ignore this change or to go to systemsettings to configure displays) had appeared, but I haven't seen it on the first screen. Probably because it was shown on the second (disconnected) screen.
4. I used present windows effect and went out of it.
5. I tried to close a Firefox window that was on the second screen from a taskbar on the first screen.
6. Got a crash.

-- Backtrace:
Application: KWin (kwin), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f688ac73780 (LWP 3406))]

Thread 2 (Thread 0x7f6872077700 (LWP 3414)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007f6889333164 in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x7f688964d0e0) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00007f6889333199 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=0x7f688965b1b4) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x00007f6880fe18ba in start_thread (arg=<value optimized out>) at pthread_create.c:300
#4  0x00007f688a4e63cd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#5  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f688ac73780 (LWP 3406)):
[KCrash Handler]
#6  KWin::CloseWindowView::hide (this=0x0) at ../../../kwin/effects/presentwindows/presentwindows.cpp:2096
#7  0x00007f687237b9dc in KWin::PresentWindowsEffect::setHighlightedWindow (this=0x1a23ca0, w=0x0) at ../../../kwin/effects/presentwindows/presentwindows.cpp:1776
#8  0x00007f6872387a23 in KWin::PresentWindowsEffect::windowClosed (this=0x1a23ca0, w=0x14d2ac0) at ../../../kwin/effects/presentwindows/presentwindows.cpp:424
#9  0x00007f688a858987 in KWin::EffectsHandlerImpl::windowClosed (this=<value optimized out>, c=0x14d2ac0) at ../../kwin/effects.cpp:322
#10 0x00007f688a7c77ed in KWin::Client::releaseWindow (this=0x16e2ea0, on_shutdown=false) at ../../kwin/client.cpp:238
#11 0x00007f688a7f52f9 in KWin::Client::windowEvent (this=0x16e2ea0, e=0x7fffaa0dfba0) at ../../kwin/events.cpp:655
#12 0x00007f688a7f5f68 in KWin::Workspace::workspaceEvent (this=0x13985c0, e=0x7fffaa0dfba0) at ../../kwin/events.cpp:323
#13 0x00007f688a7d25c8 in KWin::Application::x11EventFilter (this=0x7fffaa0dfe30, e=0x7fffaa0dfba0) at ../../kwin/main.cpp:367
#14 0x00007f6885cf32f5 in qt_x11EventFilter (ev=0x7fffaa0dfba0) at kernel/qapplication_x11.cpp:435
#15 0x00007f6885d01b07 in QApplication::x11ProcessEvent (this=<value optimized out>, event=0x7fffaa0dfba0) at kernel/qapplication_x11.cpp:3299
#16 0x00007f6885d2b1b4 in QEventDispatcherX11::processEvents (this=0x1307b40, flags=...) at kernel/qeventdispatcher_x11.cpp:132
#17 0x00007f68868e2022 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#18 0x00007f68868e226c in QEventLoop::exec (this=0x7fffaa0dfd20, flags=...) at kernel/qeventloop.cpp:201
#19 0x00007f68868e676b in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1008
#20 0x00007f688a7d4ada in kdemain (argc=<value optimized out>, argv=0x7fffaa0dfe90) at ../../kwin/main.cpp:542
#21 0x00007f688a435c4d in __libc_start_main (main=<value optimized out>, argc=<value optimized out>, ubp_av=<value optimized out>, init=<value optimized out>, fini=<value optimized out>, rtld_fini=<value optimized out>, stack_end=0x7fffaa0e04b8) at libc-start.c:228
#22 0x0000000000400699 in _start ()

Possible duplicates by query: bug 270872, bug 269270, bug 266364.

Reported using DrKonqi