| Summary: | Was painting and suddenly Krita crashed (GDB backtrace) | ||
|---|---|---|---|
| Product: | [Applications] krita | Reporter: | wolthera <griffinvalley> |
| Component: | General | Assignee: | Krita Bugs <krita-bugs-null> |
| Status: | RESOLVED FIXED | ||
| Severity: | crash | CC: | halla |
| Priority: | NOR | ||
| Version First Reported In: | git master (please specify the git hash!) | ||
| Target Milestone: | --- | ||
| Platform: | Compiled Sources | ||
| OS: | Linux | ||
| Latest Commit: | http://commits.kde.org/krita/ebc8a43ce07b6152abfb2fb88509c4bad1439f46 | Version Fixed In: | |
| Sentry Crash Report: | |||
And that's why code like QRect rect = temporaryTarget() ? temporaryTarget()->extent() : QRect(); is bad. Sure, it saves some lines, but it is _wrong_. Git commit ebc8a43ce07b6152abfb2fb88509c4bad1439f46 by Boudewijn Rempt. Committed on 13/08/2016 at 09:14. Pushed by rempt into branch 'master'. A line like QRect rect = temporaryTarget() ? temporaryTarget()->extent() : QRect(); is dangerous, since the paint device might be gone between the check and the use. It's better to get a local shared pointer to the paint device and check that. M +5 -3 libs/image/kis_paint_layer.cc M +10 -6 libs/ui/tool/strokes/kis_painter_based_stroke_strategy.cpp M +9 -5 plugins/tools/basictools/strokes/move_selection_stroke_strategy.cpp http://commits.kde.org/krita/ebc8a43ce07b6152abfb2fb88509c4bad1439f46 |
I was painting, and then suddenly Krita crashed... As I have been running krita only in gdb lately, I got a backtrace: Thread 1 "krita" received signal SIGSEGV, Segmentation fault. KisPaintDevice::extent (this=0x0) at /home/krita/kde/src/krita/libs/image/kis_paint_device.cc:1091 1091 return m_d->currentStrategy()->extent(); (gdb) thread apply all backtrace Thread 26474 (Thread 0x7fff70d5b700 (LWP 9705)): #0 pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225 #1 0x00007ffff555e738 in QWaitCondition::wait(QMutex*, unsigned long) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #2 0x00007ffff555a467 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #3 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #4 0x00007fffeef376fa in start_thread (arg=0x7fff70d5b700) at pthread_create.c:333 #5 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 26473 (Thread 0x7fff907fc700 (LWP 9704)): #0 pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225 #1 0x00007ffff555e738 in QWaitCondition::wait(QMutex*, unsigned long) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #2 0x00007ffff555a467 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #3 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #4 0x00007fffeef376fa in start_thread (arg=0x7fff907fc700) at pthread_create.c:333 #5 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 26472 (Thread 0x7fff7e33c700 (LWP 9703)): #0 pthread_cond_timedwait@@GLIBC_2.3.2 () ---Type <return> to continue, or q <return> to quit--- at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225 #1 0x00007ffff555e738 in QWaitCondition::wait(QMutex*, unsigned long) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #2 0x00007ffff555a467 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #3 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #4 0x00007fffeef376fa in start_thread (arg=0x7fff7e33c700) at pthread_create.c:333 #5 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 26471 (Thread 0x7fff7155c700 (LWP 9702)): #0 pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225 #1 0x00007ffff555e738 in QWaitCondition::wait(QMutex*, unsigned long) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #2 0x00007ffff555a467 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #3 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #4 0x00007fffeef376fa in start_thread (arg=0x7fff7155c700) at pthread_create.c:333 #5 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 26056 (Thread 0x7fff90ffd700 (LWP 9230)): #0 pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225 #1 0x00007ffff555e738 in QWaitCondition::wait(QMutex*, unsigned long) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 ---Type <return> to continue, or q <return> to quit--- #2 0x00007ffff555a467 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #3 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #4 0x00007fffeef376fa in start_thread (arg=0x7fff90ffd700) at pthread_create.c:333 #5 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 26055 (Thread 0x7fff8e840700 (LWP 9229)): #0 pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225 #1 0x00007ffff555e738 in QWaitCondition::wait(QMutex*, unsigned long) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #2 0x00007ffff555a467 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #3 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #4 0x00007fffeef376fa in start_thread (arg=0x7fff8e840700) at pthread_create.c:333 #5 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 26054 (Thread 0x7fff7f6d6700 (LWP 9228)): #0 pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225 #1 0x00007ffff555e738 in QWaitCondition::wait(QMutex*, unsigned long) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #2 0x00007ffff555a467 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #3 0x00007ffff555dc89 in ?? () ---Type <return> to continue, or q <return> to quit--- from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #4 0x00007fffeef376fa in start_thread (arg=0x7fff7f6d6700) at pthread_create.c:333 #5 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 26053 (Thread 0x7fff7fed7700 (LWP 9227)): #0 pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225 #1 0x00007ffff555e738 in QWaitCondition::wait(QMutex*, unsigned long) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #2 0x00007ffff555a467 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #3 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #4 0x00007fffeef376fa in start_thread (arg=0x7fff7fed7700) at pthread_create.c:333 #5 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 11 (Thread 0x7fffa3fff700 (LWP 10585)): #0 pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 #1 0x00007ffff555e7eb in QWaitCondition::wait(QMutex*, unsigned long) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #2 0x00007ffff6734aa2 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #3 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #4 0x00007fffeef376fa in start_thread (arg=0x7fffa3fff700) at pthread_create.c:333 ---Type <return> to continue, or q <return> to quit--- #5 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 10 (Thread 0x7fffa8853700 (LWP 10584)): #0 0x00007ffff4c1e8dd in nanosleep () at ../sysdeps/unix/syscall-template.S:84 #1 0x00007ffff5605f7d in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #2 0x00007ffff555d138 in QThread::msleep(unsigned long) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #3 0x00007ffff30dd56a in KisTileDataSwapper::run ( this=0x7ffff3563460 <(anonymous namespace)::Q_QGS_s_instance::innerFunction()::holder+64>) at /home/krita/kde/src/krita/libs/image/tiles3/swap/kis_tile_data_swapper.cpp:97 #4 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #5 0x00007fffeef376fa in start_thread (arg=0x7fffa8853700) at pthread_create.c:333 #6 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 9 (Thread 0x7fffc0ed5700 (LWP 10583)): #0 pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 #1 0x00007ffff555e7eb in QWaitCondition::wait(QMutex*, unsigned long) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #2 0x00007ffff5557e8b in QSemaphore::acquire(int) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #3 0x00007ffff30c373e in KisTileDataPooler::waitForWork ( this=0x7ffff3563420 <(anonymous namespace)::Q_QGS_s_instance::innerFunction()::holder>) ---Type <return> to continue, or q <return> to quit--- at /home/krita/kde/src/krita/libs/image/tiles3/kis_tile_data_pooler.cc:165 #4 0x00007ffff30c3efa in KisTileDataPooler::run ( this=0x7ffff3563420 <(anonymous namespace)::Q_QGS_s_instance::innerFunction()::holder>) at /home/krita/kde/src/krita/libs/image/tiles3/kis_tile_data_pooler.cc:187 #5 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #6 0x00007fffeef376fa in start_thread (arg=0x7fffc0ed5700) at pthread_create.c:333 #7 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 6 (Thread 0x7fffd882a700 (LWP 10578)): #0 0x00007ffff4c4de8d in poll () at ../sysdeps/unix/syscall-template.S:84 #1 0x00007fffee60c39c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fffee60c4ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007ffff576f4e7 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #4 0x00007ffff571defa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #5 0x00007ffff555938c in QThread::exec() () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #6 0x00007fffef162cd5 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5DBus.so.5 #7 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #8 0x00007fffeef376fa in start_thread (arg=0x7fffd882a700) at pthread_create.c:333 #9 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 ---Type <return> to continue, or q <return> to quit--- Thread 5 (Thread 0x7fffd9245700 (LWP 10577)): #0 0x00007ffff4c4de8d in poll () at ../sysdeps/unix/syscall-template.S:84 #1 0x00007fffee60c39c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fffee60c722 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007fffde6a3916 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0 #4 0x00007fffee632bc5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #5 0x00007fffeef376fa in start_thread (arg=0x7fffd9245700) at pthread_create.c:333 #6 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 4 (Thread 0x7fffd9a46700 (LWP 10576)): #0 0x00007ffff4c4de8d in poll () at ../sysdeps/unix/syscall-template.S:84 #1 0x00007fffee60c39c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fffee60c4ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007fffee60c4e9 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #4 0x00007fffee632bc5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #5 0x00007fffeef376fa in start_thread (arg=0x7fffd9a46700) at pthread_create.c:333 #6 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 3 (Thread 0x7fffda247700 (LWP 10575)): #0 0x00007ffff4c4de8d in poll () at ../sysdeps/unix/syscall-template.S:84 #1 0x00007fffee60c39c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fffee60c4ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007fffda24f28d in ?? () ---Type <return> to continue, or q <return> to quit--- from /usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so #4 0x00007fffee632bc5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #5 0x00007fffeef376fa in start_thread (arg=0x7fffda247700) at pthread_create.c:333 #6 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 2 (Thread 0x7fffe4b21700 (LWP 10574)): #0 0x00007ffff4c4de8d in poll () at ../sysdeps/unix/syscall-template.S:84 #1 0x00007ffff357cc62 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1 #2 0x00007ffff357e8d7 in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1 #3 0x00007fffe59d0dc9 in ?? () from /home/krita/Qt/5.6/gcc_64/plugins/platforms/../../lib/libQt5XcbQpa.so.5 #4 0x00007ffff555dc89 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #5 0x00007fffeef376fa in start_thread (arg=0x7fffe4b21700) at pthread_create.c:333 #6 0x00007ffff4c59b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 1 (Thread 0x7ffff7f0e8c0 (LWP 10568)): #0 KisPaintDevice::extent (this=0x0) at /home/krita/kde/src/krita/libs/image/kis_paint_device.cc:1091 #1 0x00007ffff31eca14 in KisPaintLayer::extent (this=0x13132e20) at /home/krita/kde/src/krita/libs/image/kis_paint_layer.cc:257 #2 0x00007ffff770be18 in KisNodeModel::data (this=0xd75eb20, index=..., role=120) at /home/krita/kde/src/krita/libs/ui/kis_node_model.cpp:473 #3 0x00007ffff56ea6a8 in QSortFilterProxyModel::data(QModelIndex const&, int) const () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #4 0x00007ffff78e22b6 in QModelIndex::data (arole=120, this=0x7fffffffbd00) ---Type <return> to continue, or q <return> to quit--- at /home/krita/Qt/5.6/gcc_64/include/QtCore/qabstractitemmodel.h:420 #5 KisNodeDelegate::drawThumbnail (this=this@entry=0xd754100, p=p@entry=0x7fffffffc030, option=..., index=...) at /home/krita/kde/src/krita/libs/ui/KisNodeDelegate.cpp:274 #6 0x00007ffff78e7921 in KisNodeDelegate::paint (this=0xd754100, p=0x7fffffffc030, o=..., index=...) at /home/krita/kde/src/krita/libs/ui/KisNodeDelegate.cpp:112 #7 0x00007ffff6797996 in QTreeView::drawRow(QPainter*, QStyleOptionViewItem const&, QModelIndex const&) const () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #8 0x00007ffff679c24e in QTreeView::drawTree(QPainter*, QRegion const&) const () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #9 0x00007ffff67a1676 in QTreeView::paintEvent(QPaintEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #10 0x00007ffff78ebb70 in KisNodeView::paintEvent (this=0xd74ef60, event=<optimized out>) at /home/krita/kde/src/krita/libs/ui/KisNodeView.cpp:446 #11 0x00007ffff6555308 in QWidget::event(QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #12 0x00007ffff664d56e in QFrame::event(QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #13 0x00007ffff676559b in QAbstractItemView::viewportEvent(QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #14 0x00007ffff67a2530 in QTreeView::viewportEvent(QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #15 0x00007ffff78ea96b in KisNodeView::viewportEvent (this=0xd74ef60, e=0x7fffffffc880) at /home/krita/kde/src/krita/libs/ui/KisNodeView.cpp:290 #16 0x00007ffff571fbf3 in QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #17 0x00007ffff6513025 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 ---Type <return> to continue, or q <return> to quit--- #18 0x00007ffff6517488 in QApplication::notify(QObject*, QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #19 0x00007ffff78cc837 in KisApplication::notify (this=<optimized out>, receiver=0xd74f5c0, event=0x7fffffffc880) at /home/krita/kde/src/krita/libs/ui/KisApplication.cpp:510 #20 0x00007ffff571fe80 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #21 0x00007ffff654e71a in QWidgetPrivate::sendPaintEvent(QRegion const&) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #22 0x00007ffff654ed2f in QWidgetPrivate::drawWidget(QPaintDevice*, QRegion const&, QPoint const&, int, QPainter*, QWidgetBackingStore*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #23 0x00007ffff651fbbe in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #24 0x00007ffff651fea9 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #25 0x00007ffff653f6ef in QWidgetPrivate::syncBackingStore() () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #26 0x00007ffff65553d0 in QWidget::event(QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #27 0x00007ffff666301b in QMainWindow::event(QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #28 0x00007ffff6f3c3f7 in KMainWindow::event (this=this@entry=0xca1b260, ev=ev@entry=0x229a97c0) at /home/krita/kde/src/krita/libs/widgetutils/xmlgui/kmainwindow.cpp:780 #29 0x00007ffff6f74a09 in KXmlGuiWindow::event (this=0xca1b260, ev=0x229a97c0) at /home/krita/kde/src/krita/libs/widgetutils/xmlgui/kxmlguiwindow.cpp:125 #30 0x00007ffff651304c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 #31 0x00007ffff6517488 in QApplication::notify(QObject*, QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Widgets.so.5 ---Type <return> to continue, or q <return> to quit--- #32 0x00007ffff78cc837 in KisApplication::notify (this=<optimized out>, receiver=0xca1b260, event=0x229a97c0) at /home/krita/kde/src/krita/libs/ui/KisApplication.cpp:510 #33 0x00007ffff571fe80 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #34 0x00007ffff5722673 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #35 0x00007ffff576f0f3 in ?? () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #36 0x00007fffee60c1a7 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #37 0x00007fffee60c400 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #38 0x00007fffee60c4ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #39 0x00007ffff576f4e7 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #40 0x00007ffff571defa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #41 0x00007ffff5725d9d in QCoreApplication::exec() () from /home/krita/Qt/5.6/gcc_64/lib/libQt5Core.so.5 #42 0x0000000000404bc6 in main (argc=1, argv=<optimized out>) at /home/krita/kde/src/krita/krita/main.cc:231 Reproducible: Didn't try I showed it on IRC, and tyyppi commented with this: "oh, that line checks the temporary target. I would guess you were unlucky enough to end the stroke at the right time to loose temporary target between the check for null and use of it "