Keep screen numbers the same

[ostrich]

OS: Arch Linux
MAME version: 0.266
Other software: KDE Plasma, Wayland

I have four monitors connected to my desktop on which I use MAME. I frequently disconnect one of them to connect it to a laptop. This changes the detected screen index values. E.g., when my rightmost monitor is connected to my desktop, it is detected as screen0 and MAME launches on it. When it is disconnected from my desktop, my second to rightmost monitor is detected as screen0 and MAME launches on it. In mame.ini, screen is set to auto. Because the screen index values change depending on which monitors are connected, I can't hardcode a screen value in mame.ini.

Ideally, MAME would detect which monitor is set as primary by the OS and set it as screen0. Alternatively (or maybe in addition), it would be nice to be able to identify screens by some static identifier, like how disks in Linux can be identified by UUID rather than /dev/sd* node.