Comment # 4 on bug 1118327 from Bruno Friedmann

Since the 2 last TW snapshot (20190110) I'm seeing constant crash at nextcloud
client quit.

(process:2124): GLib-GObject-WARNING **: 09:37:31.625: invalid cast from
'CloudProvidersDbusAccountSkeleton' to 'GDBusObject'
KCrash: Application 'nextcloud' crashing...


Here the backtrace will all debuginfo symbol loaded :

Application: nextcloud (nextcloud), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fb11e4e01c0 (LWP 2124))]

Thread 9 (Thread 0x7fb109805700 (LWP 12281)):
#0  0x00007fb127fbf125 in __libc_enable_asynccancel () at
../sysdeps/unix/sysv/linux/x86_64/cancellation.S:70
#1  0x00007fb127fa2d25 in __GI___libc_read (fd=36,
buf=buf@entry=0x7fb109804930, nbytes=nbytes@entry=16) at
../sysdeps/unix/sysv/linux/read.c:27
#2  0x00007fb133db0b20 in read (__nbytes=16, __buf=0x7fb109804930,
__fd=<optimized out>) at /usr/include/bits/unistd.h:44
#3  0x00007fb133db0b20 in g_wakeup_acknowledge (wakeup=0x7fb0f4004910) at
gwakeup.c:210
#4  0x00007fb133d6aabb in g_main_context_check
(context=context@entry=0x7fb0f4007710, max_priority=2147483647,
fds=fds@entry=0x56050760dcd0, n_fds=n_fds@entry=1) at gmain.c:3698
#5  0x00007fb133d6af60 in g_main_context_iterate
(context=context@entry=0x7fb0f4007710, block=block@entry=1,
dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3917
#6  0x00007fb133d6b0dc in g_main_context_iteration (context=0x7fb0f4007710,
may_block=may_block@entry=1) at gmain.c:3981
#7  0x00007fb128a8488b in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
(this=0x7fb0f4007aa0, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#8  0x00007fb128a2f02b in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>)
(this=this@entry=0x7fb109804b60, flags=..., flags@entry=...) at
../../include/QtCore/../../src/corelib/global/qflags.h:140
#9  0x00007fb1288793b6 in QThread::exec() (this=<optimized out>) at
../../include/QtCore/../../src/corelib/global/qflags.h:120
#10 0x00007fb12887a702 in QThreadPrivate::start(void*) (arg=0x560507540f70) at
thread/qthread_unix.cpp:361
#11 0x00007fb127c0f554 in start_thread (arg=<optimized out>) at
pthread_create.c:463
#12 0x00007fb127fb1ccf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7fb108f9a700 (LWP 2814)):
#0  0x00007fb127fa2d34 in __GI___libc_read (fd=38,
buf=buf@entry=0x7fb108f99930, nbytes=nbytes@entry=16) at
../sysdeps/unix/sysv/linux/read.c:27
#1  0x00007fb133db0b20 in read (__nbytes=16, __buf=0x7fb108f99930,
__fd=<optimized out>) at /usr/include/bits/unistd.h:44
#2  0x00007fb133db0b20 in g_wakeup_acknowledge (wakeup=0x7fb0fc002790) at
gwakeup.c:210
#3  0x00007fb133d6aabb in g_main_context_check
(context=context@entry=0x7fb0e8000bf0, max_priority=2147483647,
fds=fds@entry=0x7fb0e8003750, n_fds=n_fds@entry=1) at gmain.c:3698
#4  0x00007fb133d6af60 in g_main_context_iterate
(context=context@entry=0x7fb0e8000bf0, block=block@entry=1,
dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3917
#5  0x00007fb133d6b0dc in g_main_context_iteration (context=0x7fb0e8000bf0,
may_block=may_block@entry=1) at gmain.c:3981
#6  0x00007fb128a8488b in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
(this=0x7fb0e8000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#7  0x00007fb128a2f02b in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>)
(this=this@entry=0x7fb108f99b60, flags=..., flags@entry=...) at
../../include/QtCore/../../src/corelib/global/qflags.h:140
#8  0x00007fb1288793b6 in QThread::exec() (this=<optimized out>) at
../../include/QtCore/../../src/corelib/global/qflags.h:120
#9  0x00007fb12887a702 in QThreadPrivate::start(void*) (arg=0x56050748dbf0) at
thread/qthread_unix.cpp:361
#10 0x00007fb127c0f554 in start_thread (arg=<optimized out>) at
pthread_create.c:463
#11 0x00007fb127fb1ccf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 0x7fb10a807700 (LWP 2551)):
#0  0x00007fb127fa72c9 in __GI___poll (fds=0x7fb1000109a0, nfds=1, timeout=-1)
at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fb133d6afb6 in g_main_context_poll (priority=<optimized out>,
n_fds=1, fds=0x7fb1000109a0, timeout=<optimized out>, context=0x7fb10000e700)
at gmain.c:4221
#2  0x00007fb133d6afb6 in g_main_context_iterate (context=0x7fb10000e700,
block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at
gmain.c:3915
#3  0x00007fb133d6b342 in g_main_loop_run (loop=0x7fb10000e840) at gmain.c:4116
#4  0x00007fb133b8db56 in gdbus_shared_thread_func (user_data=0x7fb10000e6d0)
at gdbusprivate.c:275
#5  0x00007fb133d93506 in g_thread_proxy (data=0x5605077b82d0) at gthread.c:784
#6  0x00007fb127c0f554 in start_thread (arg=<optimized out>) at
pthread_create.c:463
#7  0x00007fb127fb1ccf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7fb10b809700 (LWP 2549)):
#0  0x00007fb127fa72c9 in __GI___poll (fds=0x560507359110, nfds=1, timeout=-1)
at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fb133d6afb6 in g_main_context_poll (priority=<optimized out>,
n_fds=1, fds=0x560507359110, timeout=<optimized out>, context=0x56050732cf50)
at gmain.c:4221
#2  0x00007fb133d6afb6 in g_main_context_iterate
(context=context@entry=0x56050732cf50, block=block@entry=1,
dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3915
#3  0x00007fb133d6b0dc in g_main_context_iteration (context=0x56050732cf50,
may_block=may_block@entry=1) at gmain.c:3981
#4  0x00007fb133d6b121 in glib_worker_main (data=<optimized out>) at
gmain.c:5861
#5  0x00007fb133d93506 in g_thread_proxy (data=0x5605077ea000) at gthread.c:784
#6  0x00007fb127c0f554 in start_thread (arg=<optimized out>) at
pthread_create.c:463
#7  0x00007fb127fb1ccf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7fb111a1c700 (LWP 2161)):
#0  0x00007fb133d6aeb8 in g_main_context_iterate
(context=context@entry=0x7fb104000bf0, block=block@entry=1,
dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3887
#1  0x00007fb133d6b0dc in g_main_context_iteration (context=0x7fb104000bf0,
may_block=may_block@entry=1) at gmain.c:3981
#2  0x00007fb128a8488b in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
(this=0x7fb104000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#3  0x00007fb128a2f02b in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>)
(this=this@entry=0x7fb111a1bb60, flags=..., flags@entry=...) at
../../include/QtCore/../../src/corelib/global/qflags.h:140
#4  0x00007fb1288793b6 in QThread::exec() (this=<optimized out>) at
../../include/QtCore/../../src/corelib/global/qflags.h:120
#5  0x00007fb12887a702 in QThreadPrivate::start(void*) (arg=0x560506e1d9a0) at
thread/qthread_unix.cpp:361
#6  0x00007fb127c0f554 in start_thread (arg=<optimized out>) at
pthread_create.c:463
#7  0x00007fb127fb1ccf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7fb11221d700 (LWP 2160)):
#0  0x00007fb127fa2d34 in __GI___libc_read (fd=19,
buf=buf@entry=0x7fb11221c900, nbytes=nbytes@entry=16) at
../sysdeps/unix/sysv/linux/read.c:27
#1  0x00007fb133db0b20 in read (__nbytes=16, __buf=0x7fb11221c900,
__fd=<optimized out>) at /usr/include/bits/unistd.h:44
#2  0x00007fb133db0b20 in g_wakeup_acknowledge (wakeup=0x7fb114001bb0) at
gwakeup.c:210
#3  0x00007fb133d6aabb in g_main_context_check
(context=context@entry=0x7fb10c000bf0, max_priority=2147483647,
fds=fds@entry=0x7fb10c035350, n_fds=n_fds@entry=1) at gmain.c:3698
#4  0x00007fb133d6af60 in g_main_context_iterate
(context=context@entry=0x7fb10c000bf0, block=block@entry=1,
dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3917
#5  0x00007fb133d6b0dc in g_main_context_iteration (context=0x7fb10c000bf0,
may_block=may_block@entry=1) at gmain.c:3981
#6  0x00007fb128a8488b in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
(this=0x7fb10c000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#7  0x00007fb128a2f02b in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>)
(this=this@entry=0x7fb11221cb30, flags=..., flags@entry=...) at
../../include/QtCore/../../src/corelib/global/qflags.h:140
#8  0x00007fb1288793b6 in QThread::exec() (this=this@entry=0x7fb1338a1d80
<(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at
../../include/QtCore/../../src/corelib/global/qflags.h:120
#9  0x00007fb133827565 in QDBusConnectionManager::run() (this=0x7fb1338a1d80
<(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at
qdbusconnection.cpp:178
#10 0x00007fb12887a702 in QThreadPrivate::start(void*) (arg=0x7fb1338a1d80
<(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at
thread/qthread_unix.cpp:361
#11 0x00007fb127c0f554 in start_thread (arg=<optimized out>) at
pthread_create.c:463
#12 0x00007fb127fb1ccf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7fb11b097700 (LWP 2154)):
#0  0x00007fb127fa72c9 in __GI___poll (fds=fds@entry=0x7fb11b096a78,
nfds=nfds@entry=1, timeout=timeout@entry=-1) at
../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fb1226b0cc7 in poll (__timeout=-1, __nfds=1, __fds=0x7fb11b096a78)
at /usr/include/bits/poll2.h:46
#2  0x00007fb1226b0cc7 in _xcb_conn_wait (c=c@entry=0x560506d953c0,
cond=cond@entry=0x560506d95400, vector=vector@entry=0x0, count=count@entry=0x0)
at xcb_conn.c:479
#3  0x00007fb1226b28ea in xcb_wait_for_event (c=c@entry=0x560506d953c0) at
xcb_in.c:697
#4  0x00007fb11bdbe5da in QXcbEventQueue::run() (this=0x560506d8a120) at
qxcbeventqueue.cpp:225
#5  0x00007fb12887a702 in QThreadPrivate::start(void*) (arg=0x560506d8a120) at
thread/qthread_unix.cpp:361
#6  0x00007fb127c0f554 in start_thread (arg=<optimized out>) at
pthread_create.c:463
#7  0x00007fb127fb1ccf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7fb11cae8700 (LWP 2153)):
#0  0x00007fb127c154dc in futex_wait_cancelable (private=0, expected=0,
futex_word=0x7fb12c8f1f30 <bmalloc::PerProcess<bmalloc::Heap>::s_memory+3120>)
at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007fb127c154dc in __pthread_cond_wait_common (abstime=0x0,
mutex=0x560506dab250, cond=0x7fb12c8f1f08
<bmalloc::PerProcess<bmalloc::Heap>::s_memory+3080>) at pthread_cond_wait.c:502
#2  0x00007fb127c154dc in __pthread_cond_wait (cond=0x7fb12c8f1f08
<bmalloc::PerProcess<bmalloc::Heap>::s_memory+3080>, mutex=0x560506dab250) at
pthread_cond_wait.c:655
#3  0x00007fb1286e287c in __gthread_cond_wait (__mutex=<optimized out>,
__cond=<optimized out>) at
/usr/src/debug/gcc8-8.2.1+r265901-1.1.x86_64/obj-x86_64-suse-linux/x86_64-suse-linux/libstdc++-v3/include/x86_64-suse-linux/bits/gthr-default.h:864
#4  0x00007fb1286e287c in
std::condition_variable::wait(std::unique_lock<std::mutex>&) (this=<optimized
out>, __lock=...) at
../../../../../libstdc++-v3/src/c++11/condition_variable.cc:53
#5  0x00007fb12be48472 in
std::_V2::condition_variable_any::wait<std::unique_lock<bmalloc::Mutex>
>(std::unique_lock<bmalloc::Mutex>&) () at
/usr/include/c++/8/condition_variable:263
#6  0x00007fb12be48472 in
std::_V2::condition_variable_any::wait<std::unique_lock<bmalloc::Mutex>,
bmalloc::AsyncTask<bmalloc::Heap, void
(bmalloc::Heap::*)()>::threadRunLoop()::{lambda()#1}>(std::unique_lock<bmalloc::Mutex>&,
bmalloc::AsyncTask<bmalloc::Heap, void
(bmalloc::Heap::*)()>::threadRunLoop()::{lambda()#1}) () at
/usr/include/c++/8/condition_variable:272
#7  0x00007fb12be48472 in bmalloc::AsyncTask<bmalloc::Heap, void
(bmalloc::Heap::*)()>::threadRunLoop() () at
/usr/src/debug/libqt5-qtwebkit-5.212~alpha2-6.1.x86_64/Source/bmalloc/bmalloc/AsyncTask.h:126
#8  0x00007fb12be4858b in bmalloc::AsyncTask<bmalloc::Heap, void
(bmalloc::Heap::*)()>::threadEntryPoint(bmalloc::AsyncTask<bmalloc::Heap, void
(bmalloc::Heap::*)()>*) () at
/usr/src/debug/libqt5-qtwebkit-5.212~alpha2-6.1.x86_64/Source/bmalloc/bmalloc/AsyncTask.h:106
#9  0x00007fb1286e80bf in std::execute_native_thread_routine(void*)
(__p=0x560506d45560) at ../../../../../libstdc++-v3/src/c++11/thread.cc:80
#10 0x00007fb127c0f554 in start_thread (arg=<optimized out>) at
pthread_create.c:463
#11 0x00007fb127fb1ccf in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7fb11e4e01c0 (LWP 2124)):
[KCrash Handler]
#6  0x00007fb133b972e8 in g_dbus_object_get_object_path (object=0x560506e2cc90)
at gdbusobject.c:110
#7  0x00007fb1338b2c1d in unexport_account (account=0x5605077fa890
[CloudProvidersAccountExporter], self=0x7fb10000d520
[CloudProvidersProviderExporter]) at
../src/cloudprovidersproviderexporter.c:110
#8  0x00007fb1338b2c1d in cloud_providers_provider_exporter_remove_account
(self=0x7fb10000d520 [CloudProvidersProviderExporter], account=0x5605077fa890
[CloudProvidersAccountExporter]) at ../src/cloudprovidersproviderexporter.c:146
#9  0x0000560506a6bf51 in
CloudProviderManager::slotFolderListChanged(QMap<QString, OCC::Folder*> const&)
(this=0x56050754fca0, folderMap=...) at
/usr/src/debug/nextcloud-client-2.5.1-3.1.x86_64/src/gui/cloudproviders/cloudprovidermanager.cpp:57
#10 0x00007fb128a5a0ab in QMetaObject::activate(QObject*, int, int, void**)
(sender=0x5605072582c0, signalOffset=<optimized out>,
local_signal_index=<optimized out>, argv=<optimized out>) at
kernel/qobject.cpp:3778
#11 0x0000560506a74745 in OCC::FolderMan::folderListChanged(QMap<QString,
OCC::Folder*> const&) (this=this@entry=0x5605072582c0, _t1=...) at
/usr/src/debug/nextcloud-client-2.5.1-3.1.x86_64/build/src/gui/nextcloud_autogen/EWIEGA46WW/moc_folderman.cpp:290
#12 0x000056050699d711 in OCC::FolderMan::unloadAndDeleteAllFolders()
(this=0x5605072582c0) at
/usr/src/debug/nextcloud-client-2.5.1-3.1.x86_64/src/gui/folderman.cpp:143
#13 0x0000560506981ef3 in OCC::Application::slotCleanup() (this=0x7ffebfdc58d0)
at /usr/src/debug/nextcloud-client-2.5.1-3.1.x86_64/src/gui/application.cpp:308
#14 0x00007fb128a5a200 in QtPrivate::QSlotObjectBase::call(QObject*, void**)
(a=0x7ffebfdc57d0, r=0x7ffebfdc58d0, this=0x56050748a530) at
../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:394
#15 0x00007fb128a5a200 in QMetaObject::activate(QObject*, int, int, void**)
(sender=0x7ffebfdc58d0, signalOffset=<optimized out>,
local_signal_index=<optimized out>, argv=<optimized out>) at
kernel/qobject.cpp:3759
#16 0x00007fb128a2f537 in
QCoreApplication::aboutToQuit(QCoreApplication::QPrivateSignal)
(this=<optimized out>, _t1=...) at .moc/moc_qcoreapplication.cpp:253
#17 0x00007fb128a337c9 in QCoreApplicationPrivate::execCleanup()
(this=0x560506da9c60) at kernel/qcoreapplication_p.h:76
#18 0x00007fb128a371ab in QCoreApplication::exec() () at
../../include/QtCore/../../src/corelib/global/qglobal.h:1038
#19 0x00007fb128e0eadc in QGuiApplication::exec() () at
kernel/qguiapplication.cpp:1779
#20 0x00007fb129421505 in QApplication::exec() () at
kernel/qapplication.cpp:2910
#21 0x000056050696c70c in main(int, char**) (argc=<optimized out>,
argv=<optimized out>) at
/usr/src/debug/nextcloud-client-2.5.1-3.1.x86_64/src/gui/main.cpp:167
[Inferior 1 (process 2124) detached]