Application: plasma-desktop (0.4)
KDE Platform Version: 4.9.00
Qt Version: 4.8.2
Operating System: Linux 3.5.2-3.fc17.x86_64 x86_64
Distribution (Platform): Fedora RPMs

-- Information about the crash:
- What I was doing when the application crashed:
I was using 4.8.5 in a VirtualBox-Session.
After the Update to 4.9 plasma-desktop crashes at every login.
It also crashes if you start it from a terminal.
Just to be sure I removed $HOME/.kde

I'm using autologin in KDM if that matters.
KDE 4.9 is from Rex Dieters KDE repo for Fedora.

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
82	T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
[Current thread is 1 (Thread 0x7fdccba47880 (LWP 1975))]

Thread 2 (Thread 0x7fdcbe721700 (LWP 1976)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:166
#1  0x00007fdce23ce777 in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x7fdce26db840) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00007fdce23ce7a9 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x00007fdcdc8a6d14 in start_thread (arg=0x7fdcbe721700) at pthread_create.c:309
#4  0x00007fdcdb12467d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

Thread 1 (Thread 0x7fdccba47880 (LWP 1975)):
[KCrash Handler]
#6  __memcpy_sse2 () at ../sysdeps/x86_64/memcpy.S:202
#7  0x00007fdce23114db in memcpy (__len=<optimized out>, __src=<optimized out>, __dest=<optimized out>) at /usr/include/bits/string3.h:52
#8  executableCopy (allocator=0x7fdce2c61960, this=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/assembler/AssemblerBuffer.h:139
#9  executableCopy (allocator=0x7fdce2c61960, this=0x7fff9271e7a0) at ../3rdparty/javascriptcore/JavaScriptCore/assembler/X86Assembler.h:1885
#10 executableCopy (allocator=0x7fdce2c61960, this=0x7fff9271e7a0) at ../3rdparty/javascriptcore/JavaScriptCore/assembler/X86Assembler.h:1583
#11 LinkBuffer (executablePool=..., masm=0x7fff9271e7a0, this=0x7fff9271e710) at ../3rdparty/javascriptcore/JavaScriptCore/assembler/LinkBuffer.h:67
#12 QTJSC::JIT::privateCompileCTIMachineTrampolines (this=0x7fff9271e7a0, executablePool=0x7fdce2c5b9e8, globalData=<optimized out>, ctiStringLengthTrampoline=0x7fdce2c5b9f0, ctiVirtualCallLink=0x7fdce2c5b9f8, ctiVirtualCall=0x7fdce2c5ba00, ctiNativeCallThunk=0x7fdce2c5ba08) at ../3rdparty/javascriptcore/JavaScriptCore/jit/JITOpcodes.cpp:1817
#13 0x00007fdce2326d3f in QTJSC::JIT::compileCTIMachineTrampolines (globalData=0x7fdce2c5a800, executablePool=executablePool@entry=0x7fdce2c5b9e8, ctiStringLengthTrampoline=ctiStringLengthTrampoline@entry=0x7fdce2c5b9f0, ctiVirtualCallLink=ctiVirtualCallLink@entry=0x7fdce2c5b9f8, ctiVirtualCall=ctiVirtualCall@entry=0x7fdce2c5ba00, ctiNativeCallThunk=ctiNativeCallThunk@entry=0x7fdce2c5ba08) at ../3rdparty/javascriptcore/JavaScriptCore/jit/JIT.h:323
#14 0x00007fdce23230c3 in QTJSC::JITThunks::JITThunks (this=0x7fdce2c5b9e8, globalData=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/jit/JITStubs.cpp:768
#15 0x00007fdce236fe68 in QTJSC::JSGlobalData::JSGlobalData (this=0x7fdce2c5a800, isShared=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/runtime/JSGlobalData.cpp:146
#16 0x00007fdce237051c in QTJSC::JSGlobalData::create () at ../3rdparty/javascriptcore/JavaScriptCore/runtime/JSGlobalData.cpp:205
#17 0x00007fdce2410d10 in QScriptEnginePrivate::QScriptEnginePrivate (this=0x1918980) at api/qscriptengine.cpp:979
#18 0x00007fdce2411c8e in QScriptEngine::QScriptEngine (this=0x7fff9271eec0, parent=0x0) at api/qscriptengine.cpp:1976
#19 0x00007fdce1e119aa in WorkspaceScripting::ScriptEngine::ScriptEngine (this=0x7fff9271eec0, corona=0x189ee10, parent=<optimized out>) at /usr/src/debug/kde-workspace-4.9.0/libs/plasmagenericshell/scripting/scriptengine.cpp:59
#20 0x00007fdce29538db in WorkspaceScripting::DesktopScriptEngine::DesktopScriptEngine (this=0x7fff9271eec0, corona=<optimized out>, startup=<optimized out>, parent=<optimized out>) at /usr/src/debug/kde-workspace-4.9.0/plasma/desktop/shell/scripting/desktopscriptengine.cpp:36
#21 0x00007fdce295af93 in DesktopCorona::evaluateScripts (this=this@entry=0x189ee10, scripts=..., isStartup=isStartup@entry=true) at /usr/src/debug/kde-workspace-4.9.0/plasma/desktop/shell/desktopcorona.cpp:363
#22 0x00007fdce295b351 in DesktopCorona::loadDefaultLayout (this=0x189ee10) at /usr/src/debug/kde-workspace-4.9.0/plasma/desktop/shell/desktopcorona.cpp:389
#23 0x00007fdce150d73c in Plasma::Corona::initializeLayout (this=0x189ee10, configName=...) at /usr/src/debug/kdelibs-4.9.0/plasma/corona.cpp:184
#24 0x00007fdce297cad3 in PlasmaApp::corona (this=this@entry=0x1756af0, createIfMissing=createIfMissing@entry=true) at /usr/src/debug/kde-workspace-4.9.0/plasma/desktop/shell/plasmaapp.cpp:850
#25 0x00007fdce297ce1d in PlasmaApp::setupDesktop (this=0x1756af0) at /usr/src/debug/kde-workspace-4.9.0/plasma/desktop/shell/plasmaapp.cpp:312
#26 0x00007fdce297e2ca in qt_static_metacall (_a=<optimized out>, _id=<optimized out>, _o=<optimized out>, _c=<optimized out>) at /usr/src/debug/kde-workspace-4.9.0/x86_64-redhat-linux-gnu/plasma/desktop/shell/plasmaapp.moc:124
#27 PlasmaApp::qt_static_metacall (_o=0x1756af0, _c=3804671360, _id=552, _a=0x10) at /usr/src/debug/kde-workspace-4.9.0/x86_64-redhat-linux-gnu/plasma/desktop/shell/plasmaapp.moc:100
#28 0x00007fdcdcc45cee in QObject::event (this=0x1756af0, e=<optimized out>) at kernel/qobject.cpp:1195
#29 0x00007fdcdbdca484 in QApplication::event (this=0x1756af0, e=0x18ad630) at kernel/qapplication.cpp:2533
#30 0x00007fdcdbdc837c in QApplicationPrivate::notify_helper (this=this@entry=0x176f370, receiver=receiver@entry=0x1756af0, e=e@entry=0x18ad630) at kernel/qapplication.cpp:4551
#31 0x00007fdcdbdcc7fa in QApplication::notify (this=0x1756af0, receiver=0x1756af0, e=0x18ad630) at kernel/qapplication.cpp:4412
#32 0x00007fdcddb6f316 in KApplication::notify (this=0x1756af0, receiver=0x1756af0, event=0x18ad630) at /usr/src/debug/kdelibs-4.9.0/kdeui/kernel/kapplication.cpp:311
#33 0x00007fdcdcc313ee in QCoreApplication::notifyInternal (this=0x1756af0, receiver=receiver@entry=0x1756af0, event=event@entry=0x18ad630) at kernel/qcoreapplication.cpp:915
#34 0x00007fdcdcc34ea1 in sendEvent (event=0x18ad630, receiver=0x1756af0) at kernel/qcoreapplication.h:231
#35 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x17028d0) at kernel/qcoreapplication.cpp:1539
#36 0x00007fdcdcc5f353 in sendPostedEvents () at kernel/qcoreapplication.h:236
#37 postEventSourceDispatch (s=s@entry=0x176be20) at kernel/qeventdispatcher_glib.cpp:279
#38 0x00007fdcd307b695 in g_main_dispatch (context=0x1771800) at gmain.c:2539
#39 g_main_context_dispatch (context=context@entry=0x1771800) at gmain.c:3075
#40 0x00007fdcd307b9c8 in g_main_context_iterate (context=context@entry=0x1771800, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3146
#41 0x00007fdcd307ba84 in g_main_context_iteration (context=0x1771800, may_block=1) at gmain.c:3207
#42 0x00007fdcdcc5f4e6 in QEventDispatcherGlib::processEvents (this=0x17041b0, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#43 0x00007fdcdbe682ee in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:207
#44 0x00007fdcdcc3013f in QEventLoop::processEvents (this=this@entry=0x7fff9271fc20, flags=...) at kernel/qeventloop.cpp:149
#45 0x00007fdcdcc303c8 in QEventLoop::exec (this=0x7fff9271fc20, flags=...) at kernel/qeventloop.cpp:204
#46 0x00007fdcdcc351b8 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1187
#47 0x00007fdce2965145 in kdemain (argc=1, argv=0x7fff9271ff18) at /usr/src/debug/kde-workspace-4.9.0/plasma/desktop/shell/main.cpp:120
#48 0x00007fdcdb054735 in __libc_start_main (main=0x4008d0 <main(int, char**)>, argc=1, ubp_av=0x7fff9271ff18, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff9271ff08) at libc-start.c:226
#49 0x0000000000400901 in _start ()

Reported using DrKonqi