Xlib kills Multithread Apps

[Norbert Schultz]

Hi out there,

I recently filled out this bug report:
https://bugs.launchpad.net/bugs/232476
but there seems no interest yet, but I think it's not that unharmfull as it 
could crash every application which uses Xlib mutlithreaded. 
A second maschine at least figures out the deadlock:
Locking assertion failure.  

Backtrace:
#0 /usr/lib/libxcb-xlib.so.0 [0x7f23e804097c]
#1 /usr/lib/libxcb-xlib.so.0(xcb_xlib_unlock+0x24) [0x7f23e8040a84]
#2 /usr/lib/libX11.so.6 [0x7f23e8fa0260]
#3 /usr/lib/libX11.so.6(XGetGeometry+0x13b) [0x7f23e8f7e59b]
#4 ./xlibtest(__gxx_personality_v0+0x349) [0x400c71]
#5 /lib/libpthread.so.0 [0x7f23e8d433f7]
#6 /lib/libc.so.6(clone+0x6d) [0x7f23e8318b2d]
Locking assertion failure.  Backtrace:
#0 /usr/lib/libxcb-xlib.so.0 [0x7f23e804097c]
#1 /usr/lib/libxcb-xlib.so.0(xcb_xlib_lock+0x15) [0x7f23e8040a15]
#2 /usr/lib/libX11.so.6 [0x7f23e8fa0323]
#3 /usr/lib/libX11.so.6(_XReply+0x14d) [0x7f23e8fa0f8d]
#4 /usr/lib/libX11.so.6(XGetGeometry+0x96) [0x7f23e8f7e4f6]
#5 ./xlibtest(__gxx_personality_v0+0x349) [0x400c71]
#6 /lib/libpthread.so.0 [0x7f23e8d433f7]
#7 /lib/libc.so.6(clone+0x6d) [0x7f23e8318b2d]

Or am I completly one and the error is somewhere at my place? Currently I 
changed my program to use Mutexes before each Xlib call.

Greetings from Lyon,
Norbert