Application: plasma-desktop (4.11.11)
KDE Platform Version: 4.14.2
Qt Version: 4.8.6
Operating System: Linux 3.16.0-38-generic x86_64
Distribution: Ubuntu 14.04.2 LTS

-- Information about the crash:
- What I was doing when the application crashed:
I am trying to add a Show Desktop widget into the default panel on the bottom, by dragging the widget from the "add widget" thing into the panel. The first time, the added widget appears as a grey box. So I tried again and add(drag) into the same position that had the grey box, resulting in the crash.
- Unusual behavior I noticed:
The first time I add the show desktop widget, the widget doesn't appear to be working and is dark grey in colour. It does nothing when I click on the widget.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f405ae857c0 (LWP 2120))]

Thread 12 (Thread 0x7f4030821700 (LWP 2147)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f4053b36ffb in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#2  0x00007f4053b37039 in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#3  0x00007f404e6ad182 in start_thread (arg=0x7f4030821700) at pthread_create.c:312
#4  0x00007f405a77847d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 11 (Thread 0x7f3faad95700 (LWP 2199)):
#0  0x00007f404dfdd61d in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f404dfdd9a9 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f404df9bef6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f404df9c0ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f405734c7be in QEventDispatcherGlib::processEvents (this=0x7f3fa40008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:436
#5  0x00007f405731e0af in QEventLoop::processEvents (this=this@entry=0x7f3faad94de0, flags=...) at kernel/qeventloop.cpp:149
#6  0x00007f405731e3a5 in QEventLoop::exec (this=this@entry=0x7f3faad94de0, flags=...) at kernel/qeventloop.cpp:204
#7  0x00007f405721ac5f in QThread::exec (this=this@entry=0x2b84510) at thread/qthread.cpp:537
#8  0x00007f40572ff823 in QInotifyFileSystemWatcherEngine::run (this=0x2b84510) at io/qfilesystemwatcher_inotify.cpp:265
#9  0x00007f405721d32f in QThreadPrivate::start (arg=0x2b84510) at thread/qthread_unix.cpp:349
#10 0x00007f404e6ad182 in start_thread (arg=0x7f3faad95700) at pthread_create.c:312
#11 0x00007f405a77847d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 10 (Thread 0x7f3fa9605700 (LWP 2298)):
#0  0x00007f404e6b2427 in __GI___pthread_getspecific (key=<optimized out>) at pthread_getspecific.c:61
#1  0x00007f404dfc13a0 in g_thread_self () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f404df9c0dd in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f405734c7be in QEventDispatcherGlib::processEvents (this=0x7f3f9c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:436
#4  0x00007f405731e0af in QEventLoop::processEvents (this=this@entry=0x7f3fa9604de0, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007f405731e3a5 in QEventLoop::exec (this=this@entry=0x7f3fa9604de0, flags=...) at kernel/qeventloop.cpp:204
#6  0x00007f405721ac5f in QThread::exec (this=this@entry=0x30d88e0) at thread/qthread.cpp:537
#7  0x00007f40572ff823 in QInotifyFileSystemWatcherEngine::run (this=0x30d88e0) at io/qfilesystemwatcher_inotify.cpp:265
#8  0x00007f405721d32f in QThreadPrivate::start (arg=0x30d88e0) at thread/qthread_unix.cpp:349
#9  0x00007f404e6ad182 in start_thread (arg=0x7f3fa9605700) at pthread_create.c:312
#10 0x00007f405a77847d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 9 (Thread 0x7f3f986ec700 (LWP 2729)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f405721d816 in wait (time=18446744073709551615, this=0x2f7ec10) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=this@entry=0x30c91a8, mutex=0x2f330e0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f4052dafe6c in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x30c9180, th=0x3ff9500) at ../../../threadweaver/Weaver/WeaverImpl.cpp:370
#4  0x00007f4052db2903 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x3ff9500, previous=0x628d040) at ../../../threadweaver/Weaver/WorkingHardState.cpp:68
#5  0x00007f4052db161f in ThreadWeaver::Thread::run (this=0x3ff9500) at ../../../threadweaver/Weaver/Thread.cpp:98
#6  0x00007f405721d32f in QThreadPrivate::start (arg=0x3ff9500) at thread/qthread_unix.cpp:349
#7  0x00007f404e6ad182 in start_thread (arg=0x7f3f986ec700) at pthread_create.c:312
#8  0x00007f405a77847d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 8 (Thread 0x7f3f976e9700 (LWP 2730)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f405721d816 in wait (time=18446744073709551615, this=0x2f7ec10) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=this@entry=0x30c91a8, mutex=0x2f330e0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f4052dafe6c in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x30c9180, th=0x67b4c30) at ../../../threadweaver/Weaver/WeaverImpl.cpp:370
#4  0x00007f4052db2903 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x67b4c30, previous=0x2dec6b0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:68
#5  0x00007f4052db161f in ThreadWeaver::Thread::run (this=0x67b4c30) at ../../../threadweaver/Weaver/Thread.cpp:98
#6  0x00007f405721d32f in QThreadPrivate::start (arg=0x67b4c30) at thread/qthread_unix.cpp:349
#7  0x00007f404e6ad182 in start_thread (arg=0x7f3f976e9700) at pthread_create.c:312
#8  0x00007f405a77847d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 7 (Thread 0x7f3f8e4c7700 (LWP 2731)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f405721d816 in wait (time=18446744073709551615, this=0x2f7ec10) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=this@entry=0x30c91a8, mutex=0x2f330e0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f4052dafe6c in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x30c9180, th=0x41d6900) at ../../../threadweaver/Weaver/WeaverImpl.cpp:370
#4  0x00007f4052db2903 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x41d6900, previous=0x0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:68
#5  0x00007f4052db291c in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x41d6900, previous=0x588f6a0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:71
#6  0x00007f4052db161f in ThreadWeaver::Thread::run (this=0x41d6900) at ../../../threadweaver/Weaver/Thread.cpp:98
#7  0x00007f405721d32f in QThreadPrivate::start (arg=0x41d6900) at thread/qthread_unix.cpp:349
#8  0x00007f404e6ad182 in start_thread (arg=0x7f3f8e4c7700) at pthread_create.c:312
#9  0x00007f405a77847d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 6 (Thread 0x7f3f8dcc6700 (LWP 2732)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f405721d816 in wait (time=18446744073709551615, this=0x2f7ec10) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=this@entry=0x30c91a8, mutex=0x2f330e0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f4052dafe6c in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x30c9180, th=0x1c84890) at ../../../threadweaver/Weaver/WeaverImpl.cpp:370
#4  0x00007f4052db2903 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x1c84890, previous=0x21da6b0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:68
#5  0x00007f4052db161f in ThreadWeaver::Thread::run (this=0x1c84890) at ../../../threadweaver/Weaver/Thread.cpp:98
#6  0x00007f405721d32f in QThreadPrivate::start (arg=0x1c84890) at thread/qthread_unix.cpp:349
#7  0x00007f404e6ad182 in start_thread (arg=0x7f3f8dcc6700) at pthread_create.c:312
#8  0x00007f405a77847d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 5 (Thread 0x7f3f8d4c5700 (LWP 2733)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f405721d816 in wait (time=18446744073709551615, this=0x2f7ec10) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=this@entry=0x30c91a8, mutex=0x2f330e0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f4052dafe6c in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x30c9180, th=0x30605a0) at ../../../threadweaver/Weaver/WeaverImpl.cpp:370
#4  0x00007f4052db2903 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x30605a0, previous=0x0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:68
#5  0x00007f4052db291c in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x30605a0, previous=0x40ad230) at ../../../threadweaver/Weaver/WorkingHardState.cpp:71
#6  0x00007f4052db161f in ThreadWeaver::Thread::run (this=0x30605a0) at ../../../threadweaver/Weaver/Thread.cpp:98
#7  0x00007f405721d32f in QThreadPrivate::start (arg=0x30605a0) at thread/qthread_unix.cpp:349
#8  0x00007f404e6ad182 in start_thread (arg=0x7f3f8d4c5700) at pthread_create.c:312
#9  0x00007f405a77847d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 4 (Thread 0x7f3f7b9ef700 (LWP 15256)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f405721d816 in wait (time=18446744073709551615, this=0x2f7ec10) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=this@entry=0x30c91a8, mutex=0x2f330e0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f4052dafe6c in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x30c9180, th=0x3fe79c0) at ../../../threadweaver/Weaver/WeaverImpl.cpp:370
#4  0x00007f4052db2903 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x3fe79c0, previous=0x0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:68
#5  0x00007f4052db291c in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x3fe79c0, previous=0x0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:71
#6  0x00007f4052db291c in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x3fe79c0, previous=0x68e1eb0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:71
#7  0x00007f4052db161f in ThreadWeaver::Thread::run (this=0x3fe79c0) at ../../../threadweaver/Weaver/Thread.cpp:98
#8  0x00007f405721d32f in QThreadPrivate::start (arg=0x3fe79c0) at thread/qthread_unix.cpp:349
#9  0x00007f404e6ad182 in start_thread (arg=0x7f3f7b9ef700) at pthread_create.c:312
#10 0x00007f405a77847d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 3 (Thread 0x7f3f7a7ee700 (LWP 15257)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f405721d816 in wait (time=18446744073709551615, this=0x2f7ec10) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=this@entry=0x30c91a8, mutex=0x2f330e0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f4052dafe6c in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x30c9180, th=0x2d2c1e0) at ../../../threadweaver/Weaver/WeaverImpl.cpp:370
#4  0x00007f4052db2903 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x2d2c1e0, previous=0x74ee470) at ../../../threadweaver/Weaver/WorkingHardState.cpp:68
#5  0x00007f4052db161f in ThreadWeaver::Thread::run (this=0x2d2c1e0) at ../../../threadweaver/Weaver/Thread.cpp:98
#6  0x00007f405721d32f in QThreadPrivate::start (arg=0x2d2c1e0) at thread/qthread_unix.cpp:349
#7  0x00007f404e6ad182 in start_thread (arg=0x7f3f7a7ee700) at pthread_create.c:312
#8  0x00007f405a77847d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 2 (Thread 0x7f3f79fed700 (LWP 15258)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f405721d816 in wait (time=18446744073709551615, this=0x2f7ec10) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=this@entry=0x30c91a8, mutex=0x2f330e0, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f4052dafe6c in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x30c9180, th=0x6e62460) at ../../../threadweaver/Weaver/WeaverImpl.cpp:370
#4  0x00007f4052db2903 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2f2eb90, th=0x6e62460, previous=0x56db170) at ../../../threadweaver/Weaver/WorkingHardState.cpp:68
#5  0x00007f4052db161f in ThreadWeaver::Thread::run (this=0x6e62460) at ../../../threadweaver/Weaver/Thread.cpp:98
#6  0x00007f405721d32f in QThreadPrivate::start (arg=0x6e62460) at thread/qthread_unix.cpp:349
#7  0x00007f404e6ad182 in start_thread (arg=0x7f3f79fed700) at pthread_create.c:312
#8  0x00007f405a77847d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 1 (Thread 0x7f405ae857c0 (LWP 2120)):
[KCrash Handler]
#6  QCoreApplication::postEvent (receiver=receiver@entry=0x686a920, event=0x2213e10, priority=priority@entry=0) at kernel/qcoreapplication.cpp:1350
#7  0x00007f4057323427 in QCoreApplication::postEvent (receiver=receiver@entry=0x686a920, event=<optimized out>) at kernel/qcoreapplication.cpp:1311
#8  0x00007f4057331094 in QObject::deleteLater (this=this@entry=0x686a920) at kernel/qobject.cpp:2087
#9  0x00007f4056740b8f in QX11Data::xdndHandleFinished (this=<optimized out>, xe=0x7ffd0c192c80, passive=<optimized out>) at kernel/qdnd_x11.cpp:1256
#10 0x00007f4056722fd3 in QApplication::x11ClientMessage (this=<optimized out>, w=0x8cbffb0, event=<optimized out>, passive_only=<optimized out>) at kernel/qapplication_x11.cpp:3259
#11 0x00007f4056732872 in QApplication::x11ProcessEvent (this=0x19bd150, event=event@entry=0x7ffd0c192c80) at kernel/qapplication_x11.cpp:3888
#12 0x00007f405675ab02 in x11EventSourceDispatch (s=0x19d2ed0, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#13 0x00007f404df9be04 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#14 0x00007f404df9c048 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x00007f404df9c0ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#16 0x00007f405734c7a1 in QEventDispatcherGlib::processEvents (this=0x195f990, flags=...) at kernel/qeventdispatcher_glib.cpp:434
#17 0x00007f405675abb6 in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#18 0x00007f405731e0af in QEventLoop::processEvents (this=this@entry=0x7ffd0c193050, flags=...) at kernel/qeventloop.cpp:149
#19 0x00007f405731e3a5 in QEventLoop::exec (this=this@entry=0x7ffd0c193050, flags=...) at kernel/qeventloop.cpp:204
#20 0x00007f4057323b79 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#21 0x00007f40566b737c in QApplication::exec () at kernel/qapplication.cpp:3828
#22 0x00007f405aa7f67c in kdemain (argc=1, argv=0x7ffd0c1932a8) at ../../../../plasma/desktop/shell/main.cpp:126
#23 0x00007f405a69fec5 in __libc_start_main (main=0x4006e0 <main(int, char**)>, argc=1, argv=0x7ffd0c1932a8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffd0c193298) at libc-start.c:287
#24 0x000000000040070e in _start ()

Reported using DrKonqi