LibX11/xcb fails to initialize something

[Brian Rogers]

On Ubuntu Jaunty, Ekiga hangs during startup before it can open any windows.
I traced the issue back to an uninitialized condition variable in libX11 xcb
code. So to anyone with mysterious freezes, this may be the fix you need.
Especially if your backtrace looks like the following one:

#0  0x00007fb79f38ca94 in __lll_lock_wait () from /lib/libpthread.so.0
#1  0x00007fb79f38a830 in pthread_cond_broadcast@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0x00007fb7a1f266b7 in wait_or_poll_for_event (dpy=0x10a6290, wait=<value optimized out>) at ../../src/xcb_io.c:141
#3  0x00007fb7a1f26a2d in process_responses (dpy=0x10a6e00, wait_for_first_event=1, current_error=0x0, current_request=0) at ../../src/xcb_io.c:166
#4  0x00007fb7a1f272e9 in _XReadEvents (dpy=0x10a6290) at ../../src/xcb_io.c:272
#5  0x00007fb7a1f05bd4 in XIfEvent (dpy=0x10a6290, event=0x7fffaa400690, predicate=0x7fb79dd02a70 <timestamp_predicate>, arg=0x2800004 <Address 0x2800004 #6  0x00007fb79dd02a39 in IA__gdk_x11_get_server_time (window=0x135a3f0) at /build/buildd/gtk+2.0-2.15.0/gdk/x11/gdkevents-x11.c:2598
#7  0x00007fb79e4782f8 in gtk_tray_icon_send_manager_message (icon=0x10d1340, message=0, window=<value optimized out>, data1=41943044, data2=0, data3=0)
#8  0x00007fb79e4785cf in gtk_tray_icon_realize (widget=0x10d1340) at /build/buildd/gtk+2.0-2.15.0/gtk/gtktrayicon-x11.c:629
#9  0x00007fb79d3f12cd in IA__g_closure_invoke (closure=0x108aa30, return_value=0x0, n_param_values=1, param_values=0x11d2280, invocation_hint=0x7fffaa4009e0)