bea6fb6c7a
The WIN_WINDOW_PROP is removed during WM_DESTROY handling, so it is not neccessary to remove it in winDestroyWindowsWindow(), and doing so opens a race condition, as we may attempt to access that property in the wndproc before the WM_DESTROY has completed. A specific example of that race is if a WM_KILLFOCUS occurs in the window between property removal and WM_DESTROY processing, where we will attempt to apply DeleteWindowFromAnyEvents() on an invalid (null) WindowPtr. Also guard against null WindowPtr in the WM_KILLFOCUS handler See http://cygwin.com/ml/cygwin-xfree/2012-01/msg00009.html Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk> Reviewed-by: Colin Harrison <colin.harrison@virgin.net>