winex11.drv: Mark drawable as dirty when setting pixel format.

dlls/winex11.drv/opengl.c

@@ -1393,17 +1393,27 @@ static struct gl_drawable *create_gl_drawable( HWND hwnd, const struct wgl_pixel
  */
 static BOOL set_win_format( HWND hwnd, const struct wgl_pixel_format *format, BOOL internal )
 {
-    struct gl_drawable *gl;
+    struct gl_drawable *old, *gl;
 
     if (!format->visual) return FALSE;
 
-    if (!(gl = create_gl_drawable( hwnd, format, FALSE, internal ))) return FALSE;
+    old = get_gl_drawable( hwnd, 0 );
+
+    if (!(gl = create_gl_drawable( hwnd, format, FALSE, internal )))
+    {
+        release_gl_drawable( old );
+        return FALSE;
+    }
 
     TRACE( "created GL drawable %lx for win %p %s\n",
            gl->drawable, hwnd, debugstr_fbconfig( format->fbconfig ));
 
+    if (old)
+        mark_drawable_dirty( old, gl );
+
     XFlush( gdi_display );
     release_gl_drawable( gl );
+    release_gl_drawable( old );
 
     win32u_set_window_pixel_format( hwnd, pixel_format_index( format ), internal );
     return TRUE;