[SDL3]SDL_SetWindowFullscreen makes the window fullscreen on the wrong monitor

[edo9300]

On Windows, if "Show window contents while dragging" is disabled, moving a non maximized window from one screen to another and snapping it to maximized, will make a subsequent call to SDL_SetWindowFullscreen maximize it to the monitor it was previously in, instead of the current one, this works properly on SDL2

[Kontrabant]

Just to check, are you setting a video mode with SDL_SetWindowFullscreenMode() before entering fullscreen, or is this fullscreen desktop?

[edo9300]

No, it's default windowed borderless fullscreen, I'm not switching to exclusive fullscreen. If the show window contents is is enabled this issue doesn't arise instead

[Kontrabant]

Found the issue, and working on a fix now. This uncovered an edge case on other platforms as well, where the window will be made fullscreen on the wrong display if a maximized window is moved to another display by the window manager.

[edo9300]

I retested this interaction on the latest sdl3 release, and it seems to be wrong again (it was working on sdl 3.1.8 and 3.1.10), but already in sdl 3.2.0 it starts behaving with this broken behaviour again

[slouken]

@Kontrabant, can you take a look?

[Kontrabant]

Will do.

[Kontrabant]

After dragging, the maximized window is made fullscreen on the correct display, but it is put on the wrong display when leaving fullscreen due to the fix needed for #12006. Working on it now.