[Qt-interest] Strange conflict with QWidget and X11/Xutil.h

[Chris]

Hi,

I've been stuck with a compilation problem in my latest project for a
long time and I've whittled it down to this short snippet (main.cpp):

#include <QApplication>
#include <QWidget>
#include <X11/Xutil.h>
int main(int argc, char *argv[])
{
	QApplication app(argc, argv);
	return app.exec();
}

I'm running Fedora 11 (qt-4.5.2-2) and if I build this I get:

g++ -c -pipe -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2
-fstack-protector --param=ssp-buffer-size=4 -m32 -march=i586
-mtune=generic -fasynchronous-unwind-tables -Wall -W -D_REENTRANT
-DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB
-I/usr/lib/qt4/mkspecs/linux-g++ -I. -I/usr/include/QtCore
-I/usr/include/QtGui -I/usr/include -I. -I. -o main.o main.cpp
In file included from /usr/include/QtCore/qstringlist.h:46,
                 from /usr/include/QtGui/qcolor.h:47,
                 from /usr/include/QtGui/qpalette.h:46,
                 from /usr/include/QtGui/qwidget.h:48,
                 from /usr/include/QtGui/QWidget:1,
                 from main.cpp:4:
/usr/include/QtCore/qdatastream.h:49:2: error: #error qdatastream.h
must be included before any header file that defines Status
In file included from /usr/include/QtCore/qstringlist.h:46,
                 from /usr/include/QtGui/qcolor.h:47,
                 from /usr/include/QtGui/qpalette.h:46,
                 from /usr/include/QtGui/qwidget.h:48,
                 from /usr/include/QtGui/QWidget:1,
                 from main.cpp:4:
/usr/include/QtCore/qdatastream.h:98: error: expected identifier before ‘int’
/usr/include/QtCore/qdatastream.h:98: error: expected unqualified-id
before ‘{’ token
/usr/include/QtCore/qdatastream.h: In function ‘QDataStream&
operator>>(QDataStream&, QHash<Key, T>&)’:
/usr/include/QtCore/qdatastream.h:338: error: expected unqualified-id
before ‘int’
/usr/include/QtCore/qdatastream.h:338: error: expected ‘;’ before ‘int’
/usr/include/QtCore/qdatastream.h:346: error: ‘Ok’ is not a member of
‘QDataStream’
/usr/include/QtCore/qdatastream.h:355: error: ‘Ok’ is not a member of
‘QDataStream’
/usr/include/QtCore/qdatastream.h:357: error: ‘oldStatus’ was not
declared in this scope
/usr/include/QtCore/qdatastream.h:357: error: ‘Ok’ is not a member of
‘QDataStream’
/usr/include/QtCore/qdatastream.h: In function ‘QDataStream&
operator>>(QDataStream&, QMap<aKey, aT>&)’:
/usr/include/QtCore/qdatastream.h:382: error: expected unqualified-id
before ‘int’
/usr/include/QtCore/qdatastream.h:382: error: expected ‘;’ before ‘int’
/usr/include/QtCore/qdatastream.h:392: error: ‘Ok’ is not a member of
‘QDataStream’
/usr/include/QtCore/qdatastream.h:401: error: ‘Ok’ is not a member of
‘QDataStream’
/usr/include/QtCore/qdatastream.h:403: error: ‘oldStatus’ was not
declared in this scope
/usr/include/QtCore/qdatastream.h:403: error: ‘Ok’ is not a member of
‘QDataStream’
make: *** [main.o] Error 1

I can probably find a way around it (by avoiding X11util.h) but should
I report a bug or does anyone have any idea why this might happen?

Cheers, Chris.