Please describe the problem:
If I minimize, then restore a Gtk main window, any windows that are transient for the window, that have been shown, then hidden (but not destroyed) throughout the lifetime of the window, will re-appear, but with their contents hidden. That is, what is displayed are "blank" windows with the shape, size and position of the windows shown earlier.

The same thing happens for pulldown menus, which I presume (without having studied the code) are implemented as transient windows without decorations.

Steps to reproduce:
1. Build and start the test application to be attached.
2. Click the "File" button so as to "pull down" the file menu.
3. Hide the menu by clicking outside the window.
4. Press the Minimize icon on the window frame.
5. Restore the window by pressing its button in the Windows toolbar


Actual results:
The window is correctly restored, but an additional gray box appears where the file"menu was displayed after step 2. If "File" is selected again, this box is replaced by the proper file menu.

Also, after step 4, an additional "box" appears at the bottom of the screen, presumably indicating that an additional window was minimized.

Expected results:
The main window (only) is minimized and restored.

Does this happen every time?
Yes

Other information:
I have a simple test application only for menus, but I've seen what I interpret as another symptom of the same problem for dialog windows.

The problem may actually be reproduced with just about any Gtk application.