[Bug 20389] Firefox/Thunderbird: Close button must be clicked twice

http://bugs.winehq.org/show_bug.cgi?id=20389

--- Comment #3 from Dmitry Timoshkov   2009-10-21 06:32:13 ---
The problem is that the app(s) fetch all client area mouse messages in its
message loop, so injected WM_LBUTTONUP message has no chance of reaching
DefWindowProc code.

A workaround is to inject WM_NCLBUTTONUP instead, and adapt the DefWindowProc
code to react on it same way as on WM_LBUTTONUP, but that won't work for
custom non-client message handlers.