Comment # 23 on bug 974627 from Stefan Hundhammer

Not very surprisingly, there is no difference in any of the relevant q*x11*cpp
files between Qt 5.5 and Qt 5.6:

[shundhammer @ morgul] ...space/src/qt-5.6.0 28 % find . -name "*x11*cpp" |
sort                     
./config.tests/qpa/egl-x11/egl-x11.cpp
./src/gui/doc/snippets/code/src_gui_kernel_qguiapplication_x11.cpp
./src/plugins/platforms/eglfs/deviceintegration/eglfs_x11/qeglfsx11integration.cpp
./src/plugins/platforms/eglfs/deviceintegration/eglfs_x11/qeglfsx11main.cpp
./src/plugins/platforms/offscreen/qoffscreenintegration_x11.cpp
./src/widgets/util/qsystemtrayicon_x11.cpp
[shundhammer @ morgul] ...space/src/qt-5.6.0 29 % foreach src ( `find . -name
"*x11*cpp" | sort` ) do
diff -q ../qt-5.5.1/$src $src
done
Files ../qt-5.5.1/./src/widgets/util/qsystemtrayicon_x11.cpp and
./src/widgets/util/qsystemtrayicon_x11.cpp differ


That last file has differences, but that one is just about system tray items
which is irrelevant here.

For this test, I used the plain tarballs from 
https://build.suse.de/package/show/SUSE:SLE-12-SP1:Update/libqt5-qtbase (Qt
5.5.1)
and
https://build.opensuse.org/package/show/KDE:Qt5/libqt5-qtbase (Qt 5.6.0)