Segfault on some applications using qt5

[BERTRAND Joël]

	Hello,

	I'm not sure you remember I have posted here a long time ago that some
applications abort with segfault on a diskless workstation. Yesterday,
as I have successfully build seamonkey 2.53.2b1 from sources, I have
upgraded this workstation from 12.0 to 12.1. I have upgraded ports also.

	Same constatation, a lot of applications abort with segfault. For
example : vlc or okular.

	I have rebuilt both applications from sources to have debug information
and I have seen that both segfault occur in libQt5Gui.so.5

	Full backtrace :
(gdb) bt
#0  0x0000000803051ed0 in ?? () from /usr/local/lib/qt5/libQt5Gui.so.5
#1  0x00000008032b7723 in ?? () from /usr/local/lib/qt5/libQt5Gui.so.5
#2  0x00000008032b92f9 in QRasterPaintEngine::fillRect(QRectF const&,
QSpanData*) () from /usr/local/lib/qt5/libQt5Gui.so.5
#3  0x00000008032de2db in QPainter::fillRect(QRect const&, QBrush const&) ()
   from /usr/local/lib/qt5/libQt5Gui.so.5
#4  0x0000000802ac4bbe in ?? () from /usr/local/lib/qt5/libQt5Widgets.so.5
#5  0x0000000802ac47a8 in QWidgetPrivate::paintBackground(QPainter*,
QRegion const&, int) const () from /usr/local/lib/qt5/libQt5Widgets.so.5
#6  0x0000000802acbcc8 in QWidgetPrivate::drawWidget(QPaintDevice*,
QRegion const&, QPoint const&, int, QPainter*, QWidgetBackingStore*) ()
   from /usr/local/lib/qt5/libQt5Widgets.so.5
#7  0x0000000802aa4a45 in ?? () from /usr/local/lib/qt5/libQt5Widgets.so.5
#8  0x0000000802aa344c in ?? () from /usr/local/lib/qt5/libQt5Widgets.so.5
#9  0x0000000802af4cf4 in ?? () from /usr/local/lib/qt5/libQt5Widgets.so.5
#10 0x0000000802af1e0a in ?? () from /usr/local/lib/qt5/libQt5Widgets.so.5
#11 0x0000000802a97ca3 in QApplicationPrivate::notify_helper(QObject*,
QEvent*)
    () from /usr/local/lib/qt5/libQt5Widgets.so.5
#12 0x0000000802a991ec in QApplication::notify(QObject*, QEvent*) ()
   from /usr/local/lib/qt5/libQt5Widgets.so.5
#13 0x0000000803a39362 in QCoreApplication::notifyInternal2(QObject*,
QEvent*)
    () from /usr/local/lib/qt5/libQt5Core.so.5
#14 0x0000000803083bcc in
QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*)
() from /usr/local/lib/qt5/libQt5Gui.so.5
#15 0x0000000803065afc in
QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>)
() from /usr/local/lib/qt5/libQt5Gui.so.5
#16 0x000000080657f8bf in ?? () from /usr/local/lib/qt5/libQt5XcbQpa.so.5
#17 0x00000008041e87d7 in g_main_context_dispatch ()
   from /usr/local/lib/libglib-2.0.so.0
#18 0x00000008041e8b9a in ?? () from /usr/local/lib/libglib-2.0.so.0
#19 0x00000008041e8c54 in g_main_context_iteration ()
   from /usr/local/lib/libglib-2.0.so.0
#20 0x0000000803a91e06 in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
() from /usr/local/lib/qt5/libQt5Core.so.5
#21 0x0000000803a34a0e in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from
/usr/local/lib/qt5/libQt5Core.so.5
#22 0x0000000803a39ace in QCoreApplication::exec() ()
   from /usr/local/lib/qt5/libQt5Core.so.5
#23 0x00000008024b50c4 in ?? ()
   from /usr/local/lib/vlc/plugins/gui/libqt_plugin.so
#24 0x00000008024b46d6 in ?? ()
   from /usr/local/lib/vlc/plugins/gui/libqt_plugin.so
#25 0x000000080027b736 in ?? () from /lib/libthr.so.3

	/usr/local/lib/qt5/libQt5Gui.so.5 is built with clang and linked
against libc++.so.1. Okular and vlc are built with gcc. Thus, I have
tried to rebuild okular and gcc with clang. I have added in /etc/make.conf:

.if ${.CURDIR:M*/multimedia/vlc}
CC=clang
CXX=clang++
CPP=clang-cpp
.endif

.if ${.CURDIR:M*/graphics/okular}
CC=clang
CXX=clang++
CPP=clang-cpp
.endif

and I have verified that both applications are now built with clang.
Same result: segfault in libQt5Gui.so.5

	To obtain more informations, I have tried to rebuild
/x11-toolkits/qt5-gui from sources, but without success . Compilation
aborts with :

In file included from image/qimage_ssse3.cpp:40:
In file included from ../../include/QtGui/qimage.h:1:
In file included from ../../include/QtGui/../../src/gui/image/qimage.h:48:
In file included from ../../include/QtGui/qtransform.h:1:
In file included from
../../include/QtGui/../../src/gui/painting/qtransform.h:43:
In file included from ../../include/QtGui/qmatrix.h:1:
In file included from
../../include/QtGui/../../src/gui/painting/qmatrix.h:45:
In file included from ../../include/QtGui/qregion.h:1:
In file included from
../../include/QtGui/../../src/gui/painting/qregion.h:49:
In file included from ../../include/QtCore/qdatastream.h:1:
In file included from
../../include/QtCore/../../src/corelib/serialization/qdatastream.h:44:
In file included from ../../include/QtCore/qiodevice.h:1:
In file included from
../../include/QtCore/../../src/corelib/io/qiodevice.h:45:
In file included from ../../include/QtCore/qobject.h:1:
In file included from
../../include/QtCore/../../src/corelib/kernel/qobject.h:54:
In file included from ../../include/QtCore/qmetatype.h:1:
../../include/QtCore/../../src/corelib/kernel/qmetatype.h:97:5: error:
division by zero in preprocessor expression
#if QT_CONFIG(easingcurve)
    ^~~~~~~~~~~~~~~~~~~~~~
../../include/QtCore/../../src/corelib/global/qglobal.h:86:30: note:
expanded from macro 'QT_CONFIG'
#define QT_CONFIG(feature) (1/QT_FEATURE_##feature == 1)
                            ~^~~~~~~~~~~~~~~~~~~~~
3 errors generated.
*** Error code 1

Stop.
make[1]: stopped in
/usr/ports/x11-toolkits/qt5-gui/work/qtbase-everywhere-src-5.14.2/src/gui
*** Error code 1

Stop.
make: stopped in /usr/ports/x11-toolkits/qt5-gui

	And I don't know what I can do to build this library...

	Best regards,

	JKB