winex11.drv/window: Query the X server for the actual rect of the window before unmapping it

dlls/winex11.drv/window.c

@@ -213,6 +213,25 @@ static BOOL has_owned_popups( HWND hwnd )
     return ret;
 }
 
+static BOOL is_actual_window_rect_mapped(const struct x11drv_win_data *data)
+{
+    XWindowAttributes attr;
+    Window child;
+    RECT rect;
+    POINT pt;
+    int x, y;
+
+    /* Query the X server for the actual position of the window,
+       as some WMs tend to mess with it, so we need to make sure
+       we aren't unmapping the window wrongly with a bogus rect */
+    XTranslateCoordinates(data->display, data->whole_window, root_window, 0, 0, &x, &y, &child);
+    XGetWindowAttributes(data->display, data->whole_window, &attr);
+
+    pt = root_to_virtual_screen(x - attr.x, y - attr.y);
+    SetRect(&rect, pt.x, pt.y, pt.x + attr.width, pt.y + attr.height);
+    return is_window_rect_mapped(&rect);
+}
+
 
 /***********************************************************************
  *              alloc_win_data
@@ -2685,7 +2704,8 @@ void X11DRV_WindowPosChanged( HWND hwnd, HWND insert_after, UINT swp_flags,
     {
         if (((swp_flags & SWP_HIDEWINDOW) && !(new_style & WS_VISIBLE)) ||
             (!event_type && !(new_style & WS_MINIMIZE) &&
-             !is_window_rect_mapped( rectWindow ) && is_window_rect_mapped( &old_window_rect )))
+             !is_window_rect_mapped( rectWindow ) && is_window_rect_mapped( &old_window_rect ) &&
+             !is_actual_window_rect_mapped( data )))
         {
             release_win_data( data );
             unmap_window( hwnd );