winex11.drv: Avoid copying invalid window bits.

[Dmitry Timoshkov]

---
 dlls/winex11.drv/window.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/dlls/winex11.drv/window.c b/dlls/winex11.drv/window.c
index 3c0f303..ec9bec2 100644
--- a/dlls/winex11.drv/window.c
+++ b/dlls/winex11.drv/window.c
@@ -1615,6 +1615,8 @@ static void move_window_bits( struct x11drv_win_data *data, const RECT *old_rect
         hdc_src = hdc_dst = GetDCEx( data->hwnd, 0, DCX_CACHE );
     }
 
+    ExcludeUpdateRgn( hdc_dst, data->hwnd );
+
     code = X11DRV_START_EXPOSURES;
     ExtEscape( hdc_dst, X11DRV_ESCAPE, sizeof(code), (LPSTR)&code, 0, NULL );
 
-- 
1.7.0.6