[SDL3, X11] fullscreen transitions cause displays to behave as though disconnected; fullscreen flag not set correctly

[MDZhB]

[SDL3, X11] fullscreen transitions cause displays to behave as though disconnected; fullscreen flag not set correctly

[Kontrabant]

In the case of the incorrect window flags, the sync function just needs to allow for extra time if a mode switch is in progress. I'll fix that up tomorrow.

As for everything exploding when switching modes on multi-monitor setups, I'll have to ping @icculus for help on that. I've never touched the XRandR code, and, honestly, I don't think I've ever had X11 work correctly when switching modes on anything but the primary display, and even then, occasionally the other displays would just disappear and need to be re-enabled, or end up in a weird state.

To be fair, the X11 mode switching code does say:

/* I'm becoming more and more convinced that the application should never
 * use XRandR, and it's the window manager's responsibility to track and
 * manage display modes for fullscreen windows.  Right now XRandR is completely
 * broken with respect to window manager behavior on every window manager that
 * I can find.  For example, on Unity 3D if you show a fullscreen window while
 * the resolution is changing (within ~250 ms) your window will retain the
 * fullscreen state hint but be decorated and windowed.
 *
 * However, many people swear by it, so let them swear at it. :)
 */

[Kontrabant]

The incorrect flags should be fixed now.

[MDZhB]

Fullscreen flag looks fixed on my end as well. Thank you very much for taking care of it so quickly, I appreciate it.

[Kontrabant]

I looked into the mode switching issue, and, unless someone can point out something specific that SDL is doing wrong, I don't think there is anything to be done here.

Anything that does mode switching, be it SDL, GLFW, WINE, etc… seems to randomly leave my multi-display setup in a broken state, particularly when switching the mode on a non-primary display. Sometimes the display won't switch back, sometimes a display will behave as if disconnected until entering the settings and re-enabling it, sometimes there are weird scrolling issues, and so on. It's likely just a case of X mode switching being a janky pile of excrement in general.