Keith Packard authored Oct 11, 2008 and Jamey Sharp committed Nov 04, 2008

As Xlib queues events internally, we must prevent multiple Xlib threads from
entering XCB to wait for an event in case the queued event is to be
delivered to the thread which didn't manage to read it. In other words, let
only one Xlib thread into xcb_wait_for_event at a time.

Jamey Sharp looked over my shoulder while making this fix and, while hating
my whitespace conventions, appears happy enough with the actual code.

Signed-off-by: Keith Packard <keithp@keithp.com>