If mpv is launched with --fs, the x11 code tries to reset the size and
position of the window when the fullscreen exits. This has bad behavior
with multiple monitors because the saved nofsrc is not reliable in many
situations. Particularly if the window manager moves the fullscreen
window somewhere else while mpv is fullscreen. The result will be that
exiting fullscreen always goes back to screen 0.
Fix this by translating the rc coordinates of the nofsrc rc to the new
monitor when we're leaving fullscreen from an initial --fs case. By
giving get_current_display a specific rc, we can return what xrandr
display the coordinates are associated with and decide if the nofsrc
should be translated to its new location. After that bit of math, the
usual move/resize logic takes care of the rest but this time it actually
works off of the correct position. Fixes#14226.
52bdeb07a1