tablet crash

[Fazekas László]

I've just tried a Wacom tablet with Krita (to try Dmitry's new eraser 
mode later), but it always crashes the program when I close the "new 
document" dialog with the stylus. This not happens if I'm using the 
mouse. It seems that Krita processes some tablet events after the window 
closed (and probably deleted): the window address is not null but points 
to an invalid address.

This is not a bug report because I'm not sure about what Qt version 
needed for Krita right now. I see in the code that there are tablet 
related parts specially for Qt 5.5. I'm using Qt 5.4, maybe that's the 
problem? Is Krita still compatible with Qt 5.4? Or we still care about 
bugs for Qt 5.4?

Fazek

If somebody interested, this is the stack when it crashed:

Core was generated by `/home/fazekas/Asztal/krita-dev/i/bin/krita'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00007f1bfd7b542a in 
QtSharedPointer::ExternalRefCountData::getAndRef(QObject const*) () from 
/opt/qt54/lib/libQt5Core.so.5
(gdb) bt
#0  0x00007f1bfd7b542a in 
QtSharedPointer::ExternalRefCountData::getAndRef(QObject const*) () from 
/opt/qt54/lib/libQt5Core.so.5
#1  0x00007f1bff14eaf7 in QWeakPointer<QWindow> (ptr=0x8afba40, 
this=0x8ac50c0) at /opt/qt54/include/QtCore/qsharedpointer_impl.h:695
#2  QPointer (p=0x8afba40, this=0x8ac50c0) at 
/opt/qt54/include/QtCore/qpointer.h:62
#3  UserEvent (t=QWindowSystemInterfacePrivate::Tablet, time=25202, 
w=0x8afba40, this=0x8ac50b0)
     at 
/home/fazekas/Asztal/krita-dev/krita/libs/ui/input/wintab/qxcbconnection.cpp:480
#4  InputEvent (mods=..., t=QWindowSystemInterfacePrivate::Tablet, 
time=25202, w=0x8afba40, this=0x8ac50b0)
     at 
/home/fazekas/Asztal/krita-dev/krita/libs/ui/input/wintab/qxcbconnection.cpp:492
#5  TabletEvent (mods=..., uid=760565727315, z=0, rotation=0, 
tpressure=0, yTilt=9, xTilt=-28, pressure=0, b=..., pointerType=1, 
device=2, global=...,
     local=..., time=25202, w=0x8afba40, this=0x8ac50b0) at 
/home/fazekas/Asztal/krita-dev/krita/libs/ui/input/wintab/qxcbconnection.cpp:509
#6  QWindowSystemInterface::handleTabletEvent (w=0x8afba40, local=..., 
global=..., device=2, pointerType=1, buttons=..., pressure=0, xTilt=-28, 
yTilt=9,
     tangentialPressure=0, rotation=0, z=0, uid=760565727315, modifiers=...)
     at 
/home/fazekas/Asztal/krita-dev/krita/libs/ui/input/wintab/qxcbconnection.cpp:563
#7  0x00007f1bff149320 in QXcbConnection::xi2ReportTabletEvent 
(this=this at entry=0x13e57d0, tabletData=..., event=event at entry=0x8a82ed0)
     at 
/home/fazekas/Asztal/krita-dev/krita/libs/ui/input/wintab/qxcbconnection_xi2.cpp:887
#8  0x00007f1bff14967b in QXcbConnection::xi2HandleTabletEvent 
(this=this at entry=0x13e57d0, event=event at entry=0x8a82ed0, 
tabletData=0x13e6198,
     window=window at entry=0x8afba40) at 
/home/fazekas/Asztal/krita-dev/krita/libs/ui/input/wintab/qxcbconnection_xi2.cpp:721
#9  0x00007f1bff14c7d1 in QXcbConnection::xi2HandleEvent 
(this=0x13e57d0, event=0x8a82ed0)
     at 
/home/fazekas/Asztal/krita-dev/krita/libs/ui/input/wintab/qxcbconnection_xi2.cpp:502
#10 0x00007f1bff14fa76 in KisXi2EventFilter::nativeEventFilter 
(this=0x7f1bff599640 
<_ZZN12_GLOBAL__N_116Q_QGS_s_instance13innerFunctionEvE6holder>,
     eventType=..., message=0x7f1be8006f50, result=<optimized out>) at 
/home/fazekas/Asztal/krita-dev/krita/libs/ui/input/wintab/kis_xi2_event_filter.cpp:115
#11 0x00007f1bfd94e840 in 
QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, 
long*) () from /opt/qt54/lib/libQt5Core.so.5
#12 0x00007f1bef3d3c2d in 
QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () from 
/opt/qt54/plugins/platforms/libqxcb.so
#13 0x00007f1bef3d4f1b in QXcbConnection::processXcbEvents() () from 
/opt/qt54/plugins/platforms/libqxcb.so
#14 0x00007f1bfd981cf6 in QObject::event(QEvent*) () from 
/opt/qt54/lib/libQt5Core.so.5
#15 0x00007f1bfe26f81c in QApplicationPrivate::notify_helper(QObject*, 
QEvent*) () from /opt/qt54/lib/libQt5Widgets.so.5
#16 0x00007f1bfe274670 in QApplication::notify(QObject*, QEvent*) () 
from /opt/qt54/lib/libQt5Widgets.so.5
#17 0x00007f1bff0a1d47 in KisApplication::notify (this=<optimized out>, 
receiver=0xe177f0, event=0x7f1be8006e60)
     at /home/fazekas/Asztal/krita-dev/krita/libs/ui/KisApplication.cpp:514
#18 0x00007f1bfd951665 in QCoreApplication::notifyInternal(QObject*, 
QEvent*) () from /opt/qt54/lib/libQt5Core.so.5
#19 0x00007f1bfd9534ff in 
QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) 
() from /opt/qt54/lib/libQt5Core.so.5
#20 0x00007f1bfd9a9573 in postEventSourceDispatch(_GSource*, int 
(*)(void*), void*) () from /opt/qt54/lib/libQt5Core.so.5
#21 0x00007f1bf7d6be04 in g_main_context_dispatch () from 
/lib/x86_64-linux-gnu/libglib-2.0.so.0
#22 0x00007f1bf7d6c048 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#23 0x00007f1bf7d6c0ec in g_main_context_iteration () from 
/lib/x86_64-linux-gnu/libglib-2.0.so.0
#24 0x00007f1bfd9a89ec in 
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) 
() from /opt/qt54/lib/libQt5Core.so.5
#25 0x00007f1bfd94f5cb in 
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from 
/opt/qt54/lib/libQt5Core.so.5
#26 0x00007f1bfd956c36 in QCoreApplication::exec() () from 
/opt/qt54/lib/libQt5Core.so.5
#27 0x0000000000402e1b in main (argc=1, argv=0x7ffc6e126fb8) at 
/home/fazekas/Asztal/krita-dev/krita/krita/main.cc:178