Application: digikam (4.14.0)
KDE Platform Version: 4.14.16
Qt Version: 4.8.7
Operating System: Linux 4.15.0-24-generic x86_64
Distribution: Linux Mint 18.3 Sylvia

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

Attempting to use Export to Dropbox plugin

Main Menu -> select Export -. select Export to Dropbox

Export to Dropbox window opens, then after a few seconds digiKam crashes.

The crash can be reproduced every time.

-- Backtrace:
Application: digiKam (digikam), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7efc3a3c9b80 (LWP 19029))]

Thread 6 (Thread 0x7efb5a528700 (LWP 19094)):
#0  0x00007efc2f891360 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007efc339713a6 in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#2  0x00007efba05cc76e in KIPIPlugins::KPRawThumbThread::run() () at /usr/lib/digikam/libkipiplugins.so.4.14.0
#3  0x00007efc33970e3c in  () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#4  0x00007efc2f88b6ba in start_thread (arg=0x7efb5a528700) at pthread_create.c:333
#5  0x00007efc32e1841d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7efbfffff700 (LWP 19037)):
#0  0x00007efc2f891360 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007efc339713a6 in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#2  0x00007efc37f9e352 in  () at /usr/lib/digikam/libdigikamcore.so.4.14.0
#3  0x00007efc33970e3c in  () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#4  0x00007efc2f88b6ba in start_thread (arg=0x7efbfffff700) at pthread_create.c:333
#5  0x00007efc32e1841d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7efc04eda700 (LWP 19032)):
#0  0x00007efc32e0c74d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007efc2b02338c in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7efbf8003460, timeout=<optimized out>, context=0x7efbf80009a0) at /build/glib2.0-prJhLS/glib2.0-2.48.2/./glib/gmain.c:4135
#2  0x00007efc2b02338c in g_main_context_iterate (context=context@entry=0x7efbf80009a0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-prJhLS/glib2.0-2.48.2/./glib/gmain.c:3835
#3  0x00007efc2b02349c in g_main_context_iteration (context=0x7efbf80009a0, may_block=1) at /build/glib2.0-prJhLS/glib2.0-2.48.2/./glib/gmain.c:3901
#4  0x00007efc33ab12ce in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#5  0x00007efc33a7f18f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#6  0x00007efc33a7f4f5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#7  0x00007efc3396e549 in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#8  0x00007efc33a5f223 in  () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#9  0x00007efc33970e3c in  () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#10 0x00007efc2f88b6ba in start_thread (arg=0x7efc04eda700) at pthread_create.c:333
#11 0x00007efc32e1841d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7efc056db700 (LWP 19031)):
#0  0x00007efc2f891360 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007efc339713a6 in QWaitCondition::wait(QMutex*, unsigned long) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#2  0x00000000006047f4 in  ()
#3  0x00007efc33970e3c in  () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#4  0x00007efc2f88b6ba in start_thread (arg=0x7efc056db700) at pthread_create.c:333
#5  0x00007efc32e1841d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7efc0dc82700 (LWP 19030)):
#0  0x00007efc32e0c74d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007efc183ed64c in  () at /lib/x86_64-linux-gnu/libusb-1.0.so.0
#2  0x00007efc2f88b6ba in start_thread (arg=0x7efc0dc82700) at pthread_create.c:333
#3  0x00007efc32e1841d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7efc3a3c9b80 (LWP 19029)):
[KCrash Handler]
#6  0x00007efc339bfe9f in QString::operator=(QString const&) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#7  0x00007efba0388f6d in  () at /usr/lib/kde4/kipiplugin_dropbox.so
#8  0x00007efba038999c in  () at /usr/lib/kde4/kipiplugin_dropbox.so
#9  0x00007efba038a20c in  () at /usr/lib/kde4/kipiplugin_dropbox.so
#10 0x00007efc33a95010 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#11 0x00007efc33f17c92 in KJob::result(KJob*) () at /usr/lib/libkdecore.so.5
#12 0x00007efc33f17ce0 in KJob::emitResult() () at /usr/lib/libkdecore.so.5
#13 0x00007efc35c7fa1e in KIO::SimpleJob::slotFinished() () at /usr/lib/libkio.so.5
#14 0x00007efc35c80f21 in KIO::TransferJob::slotFinished() () at /usr/lib/libkio.so.5
#15 0x00007efc33a95010 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#16 0x00007efc35d2e546 in KIO::SlaveInterface::dispatch(int, QByteArray const&) () at /usr/lib/libkio.so.5
#17 0x00007efc35d2b39d in KIO::SlaveInterface::dispatch() () at /usr/lib/libkio.so.5
#18 0x00007efc35d1dbc1 in KIO::Slave::gotInput() () at /usr/lib/libkio.so.5
#19 0x00007efc33a95010 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#20 0x00007efc35c45ba4 in  () at /usr/lib/libkio.so.5
#21 0x00007efc33a9adb1 in QObject::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#22 0x00007efc34490fdc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#23 0x00007efc34497f16 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#24 0x00007efc351f664a in KApplication::notify(QObject*, QEvent*) () at /usr/lib/libkdeui.so.5
#25 0x00007efc33a8090d in QCoreApplication::notifyInternal(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#26 0x00007efc33a843c6 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#27 0x00007efc33ab113e in  () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#28 0x00007efc2b023197 in g_main_context_dispatch (context=0x2ce51e0) at /build/glib2.0-prJhLS/glib2.0-2.48.2/./glib/gmain.c:3154
#29 0x00007efc2b023197 in g_main_context_dispatch (context=context@entry=0x2ce51e0) at /build/glib2.0-prJhLS/glib2.0-2.48.2/./glib/gmain.c:3769
#30 0x00007efc2b0233f0 in g_main_context_iterate (context=context@entry=0x2ce51e0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-prJhLS/glib2.0-2.48.2/./glib/gmain.c:3840
#31 0x00007efc2b02349c in g_main_context_iteration (context=0x2ce51e0, may_block=1) at /build/glib2.0-prJhLS/glib2.0-2.48.2/./glib/gmain.c:3901
#32 0x00007efc33ab12ae in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#33 0x00007efc3453e616 in  () at /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#34 0x00007efc33a7f18f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#35 0x00007efc33a7f4f5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#36 0x00007efc33a854b9 in QCoreApplication::exec() () at /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#37 0x000000000049649e in  ()
#38 0x00007efc32d31830 in __libc_start_main (main=0x495210, argc=1, argv=0x7ffcf0f82e88, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffcf0f82e78) at ../csu/libc-start.c:291
#39 0x00000000004994a9 in _start ()

Reported using DrKonqi