Bug 385209

Application: kate (3.13.3)
KDE Platform Version: 4.13.3
Qt Version: 4.8.6
Operating System: Linux 3.13.0-132-generic i686
Distribution: Ubuntu 14.04.5 LTS

-- Information about the crash:
Simplest way to reproduce - the attached stack trace is from such an operation: 

- open kate
- type something into the file created by default
- File -> Save as ...

Expected: save as dialog appears
Actual: Kate segfaults

Vlc crashes similarly on File -> Open file ..., Chromium web browsers does not crash trying to select a picture for upload, but I do get the KDE crash reporting window instead of the file open dialog.

If I try kdialog --msgbox "something" from the command line, it works as expected.

The crash can be reproduced every time, in every application.

I tried sudo apt-get install --reinstall for several packages, the various applications and kde-baseapps among them, but it didn't help.

This only started happening since a few updates ago, but I can't pinpoint the exact point in time.

-- Backtrace:
Application: Kate (kate), signal: Segmentation fault
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0xb4d85740 (LWP 24727))]

Thread 4 (Thread 0xb1733b40 (LWP 24728)):
#0  __pthread_mutex_unlock_usercnt (mutex=0xb0e00558, decr=1) at pthread_mutex_unlock.c:52
#1  0xb76bf7a4 in pthread_mutex_unlock (mutex=0xb0e00558) at forward.c:194
#2  0xb5e92120 in g_mutex_unlock () from /lib/i386-linux-gnu/libglib-2.0.so.0
#3  0xb5e4c99e in g_main_context_prepare () from /lib/i386-linux-gnu/libglib-2.0.so.0
#4  0xb5e4d2df in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#5  0xb5e4d528 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#6  0xb621495f in QEventDispatcherGlib::processEvents (this=0xb0e00468, flags=...) at kernel/qeventdispatcher_glib.cpp:436
#7  0xb61e3823 in QEventLoop::processEvents (this=this@entry=0xb1733258, flags=...) at kernel/qeventloop.cpp:149
#8  0xb61e3b49 in QEventLoop::exec (this=this@entry=0xb1733258, flags=...) at kernel/qeventloop.cpp:204
#9  0xb60d023d in QThread::exec (this=this@entry=0xa1a3858) at thread/qthread.cpp:537
#10 0xb61c3c44 in QInotifyFileSystemWatcherEngine::run (this=0xa1a3858) at io/qfilesystemwatcher_inotify.cpp:265
#11 0xb60d2b6f in QThreadPrivate::start (arg=0xa1a3858) at thread/qthread_unix.cpp:349
#12 0xb5f33f72 in start_thread (arg=0xb1733b40) at pthread_create.c:312
#13 0xb76b23ee in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:129

Thread 3 (Thread 0xb0cd0b40 (LWP 24729)):
#0  0xb77a4428 in __kernel_vsyscall ()
#1  0xb5f37d0b in pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_wait.S:187
#2  0xb76bf55c in __pthread_cond_wait (cond=0xb1c6b8d0, mutex=0xb1c6b8b8) at forward.c:149
#3  0xb1b68c92 in ?? () from /usr/lib/i386-linux-gnu/libQtScript.so.4
#4  0xb1b68cdf in ?? () from /usr/lib/i386-linux-gnu/libQtScript.so.4
#5  0xb5f33f72 in start_thread (arg=0xb0cd0b40) at pthread_create.c:312
#6  0xb76b23ee in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:129

Thread 2 (Thread 0xadf30b40 (LWP 24731)):
#0  0xb77a4428 in __kernel_vsyscall ()
#1  0xb76a347b in poll () at ../sysdeps/unix/syscall-template.S:81
#2  0xb5e5c20b in g_poll () from /lib/i386-linux-gnu/libglib-2.0.so.0
#3  0xb5e4d3e8 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#4  0xb5e4d528 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#5  0xb621495f in QEventDispatcherGlib::processEvents (this=0xaed00468, flags=...) at kernel/qeventdispatcher_glib.cpp:436
#6  0xb61e3823 in QEventLoop::processEvents (this=this@entry=0xadf30258, flags=...) at kernel/qeventloop.cpp:149
#7  0xb61e3b49 in QEventLoop::exec (this=this@entry=0xadf30258, flags=...) at kernel/qeventloop.cpp:204
#8  0xb60d023d in QThread::exec (this=this@entry=0xa5f82e0) at thread/qthread.cpp:537
#9  0xb61c3c44 in QInotifyFileSystemWatcherEngine::run (this=0xa5f82e0) at io/qfilesystemwatcher_inotify.cpp:265
#10 0xb60d2b6f in QThreadPrivate::start (arg=0xa5f82e0) at thread/qthread_unix.cpp:349
#11 0xb5f33f72 in start_thread (arg=0xadf30b40) at pthread_create.c:312
#12 0xb76b23ee in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:129

Thread 1 (Thread 0xb4d85740 (LWP 24727)):
[KCrash Handler]
#7  0xb57a3ca9 in KFileDialog::KFileDialog (this=0xbfc46b20, startDir=..., filter=..., parent=0xa760318, customWidget=0x0) at ../../kio/kfile/kfiledialog.cpp:266
#8  0xb579f72d in KEncodingFileDialog::KEncodingFileDialog (this=0xbfc46b20, startDir=..., encoding=..., filter=..., caption=..., type=KFileDialog::Saving, parent=0xa760318) at ../../kio/kfile/kencodingfiledialog.cpp:41
#9  0xb57a03c4 in KEncodingFileDialog::getSaveUrlAndEncoding (encoding=..., dir=..., filter=..., parent=parent@entry=0xa760318, caption=...) at ../../kio/kfile/kencodingfiledialog.cpp:199
#10 0xb1d7cc93 in KateDocument::documentSaveAs (this=0xa67df38) at ../../part/document/katedocument.cpp:3913
#11 0xb1d9699b in KateDocument::qt_static_metacall (_o=<optimized out>, _id=<optimized out>, _a=0xbfc46ce8, _c=<optimized out>) at ./katedocument.moc:281
#12 0xb61fa0f7 in QMetaObject::activate (sender=sender@entry=0xa79c528, m=m@entry=0xb75a2718 <QAction::staticMetaObject>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0xbfc46ce8) at kernel/qobject.cpp:3539
#13 0xb6c4172d in QAction::triggered (this=this@entry=0xa79c528, _t1=false) at .moc/release-shared/moc_qaction.cpp:276
#14 0xb6c43324 in QAction::activate (this=this@entry=0xa79c528, event=event@entry=QAction::Trigger) at kernel/qaction.cpp:1257
#15 0xb70e7e7b in QMenuPrivate::activateCausedStack (this=0x9f94be0, causedStack=..., action=0xa79c528, action_e=QAction::Trigger, self=true) at widgets/qmenu.cpp:1038
#16 0xb70ecf28 in QMenuPrivate::activateAction (this=this@entry=0x9f94be0, action=action@entry=0xa79c528, action_e=action_e@entry=QAction::Trigger, self=self@entry=true) at widgets/qmenu.cpp:1130
#17 0xb70f0f79 in QMenu::mouseReleaseEvent (this=this@entry=0x9f81608, e=e@entry=0xbfc47314) at widgets/qmenu.cpp:2372
#18 0xb667743e in KMenu::mouseReleaseEvent (this=0x9f81608, e=0xbfc47314) at ../../kdeui/widgets/kmenu.cpp:464
#19 0xb6ca240a in QWidget::event (this=this@entry=0x9f81608, event=event@entry=0xbfc47314) at kernel/qwidget.cpp:8376
#20 0xb70f143f in QMenu::event (this=0x9f81608, e=0xbfc47314) at widgets/qmenu.cpp:2481
#21 0xb6c487f4 in QApplicationPrivate::notify_helper (this=0x9d14370, receiver=receiver@entry=0x9f81608, e=0xbfc47314) at kernel/qapplication.cpp:4567
#22 0xb6c50ea0 in QApplication::notify (this=0xbfc4793c, receiver=receiver@entry=0x9f81608, e=e@entry=0xbfc47314) at kernel/qapplication.cpp:4110
#23 0xb65a6b64 in KApplication::notify (this=0xbfc4793c, receiver=0x9f81608, event=0xbfc47314) at ../../kdeui/kernel/kapplication.cpp:311
#24 0xb61e4e4a in QCoreApplication::notifyInternal (this=0xbfc4793c, receiver=receiver@entry=0x9f81608, event=event@entry=0xbfc47314) at kernel/qcoreapplication.cpp:953
#25 0xb6c4eb53 in sendEvent (event=<optimized out>, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#26 QApplicationPrivate::sendMouseEvent (receiver=0x9f81608, event=event@entry=0xbfc47314, alienWidget=0x0, nativeWidget=nativeWidget@entry=0x9f81608, buttonDown=buttonDown@entry=0xb75bfce4 <qt_button_down>, lastMouseReceiver=..., spontaneous=spontaneous@entry=true) at kernel/qapplication.cpp:3178
#27 0xb6cd2bd0 in QETWidget::translateMouseEvent (this=0x9f81608, event=event@entry=0xbfc4753c) at kernel/qapplication_x11.cpp:4568
#28 0xb6cd1ef5 in QApplication::x11ProcessEvent (this=0xbfc4793c, event=event@entry=0xbfc4753c) at kernel/qapplication_x11.cpp:3627
#29 0xb6cfd554 in x11EventSourceDispatch (s=0x9d09690, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#30 0xb5e4d1e3 in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#31 0xb5e4d468 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#32 0xb5e4d528 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#33 0xb621495f in QEventDispatcherGlib::processEvents (this=this@entry=0x9cdbf08, flags=...) at kernel/qeventdispatcher_glib.cpp:436
#34 0xb6cfd60e in QGuiEventDispatcherGlib::processEvents (this=0x9cdbf08, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#35 0xb61e3823 in QEventLoop::processEvents (this=this@entry=0xbfc477f8, flags=...) at kernel/qeventloop.cpp:149
#36 0xb61e3b49 in QEventLoop::exec (this=this@entry=0xbfc477f8, flags=...) at kernel/qeventloop.cpp:204
#37 0xb61e98fe in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#38 0xb6c46a24 in QApplication::exec () at kernel/qapplication.cpp:3828
#39 0xb779d92d in kdemain (argc=2, argv=0xbfc47a44) at ../../../kate/app/katemain.cpp:381
#40 0x0804854b in main (argc=2, argv=0xbfc47a44) at kate_dummy.cpp:3

Possible duplicates by query: bug 324448, bug 277531.