On restore, LayoutSaver assigns zero width/height to windows from disconnected screen

[petrmanek]

Hi, I have a very specific bug report that concerns LayoutSaver and multiple-screen setups. This was reported to me by a user of my app, which relies on KDDW. Happens on the latest Linux Mint.

Steps to reproduce:

1. Use a PC with more than 1 screen.
2. Open the example app, create a layout that has widgets/windows in all screens.
3. Save the layout to a file and close the app.
4. Disconnect one of the screens from the PC.
5. Open the example app again and restore the layout from file.

Expected output: The layout would be restored as much as possible, with windows/widgets from the unavailable screen moved to another available screen.

Actual outcome: The windows/widgets from now unavailable screen are assigned zero width and height, and are hard to find and change back to reasonable size.