Restoring minimized window on macOS 10.15 can result in an offset viewport

[blast007]

On macOS 10.15, if you are running the game at a resolution different from the desktop resolution, restoring a minimized window by clicking on the application icon in the dock (instead of the minimized window icon) results in an offset viewport. This occurs in both the stock 2.4.20 and with the code in PR 251.

[blast007]

I need to test this a lot more to make sure it consistently works and doesn't have any side effects, but this seems to fix the offset viewport issue. I added this to SDL2Display::setupEvent within the SDL_WINDOWEVENT switch statement.

case SDL_WINDOWEVENT_MOVED:
{
    SDL_Window *window = SDL_GetWindowFromID(event.window.windowID);
    if (event.window.data2 < 0 && SDL_GetWindowFlags(window) & SDL_WINDOW_FULLSCREEN) {
        SDL_SetWindowFullscreen(window, 0);
        SDL_SetWindowFullscreen(window, SDL_WINDOW_FULLSCREEN);
    }
}
break;

So far I have only tested the change with a single display. I'll need to test with multi-display configurations.

---

Here was a log of window events that led to the above change. I was running this with a single display at 2560x1440 with the client resolution set to 1280x720.

Starting client full-screen at a non-desktop resolution:

2021-01-03 20:08:39.939 BZFlag[5334:69829] INFO: Window 1 shown
2021-01-03 20:08:39.940 BZFlag[5334:69829] INFO: Window 1 exposed
2021-01-03 20:08:39.940 BZFlag[5334:69829] INFO: Window 1 hidden
2021-01-03 20:08:39.940 BZFlag[5334:69829] INFO: Window 2 moved to 0,0
2021-01-03 20:08:39.940 BZFlag[5334:69829] INFO: Window 2 size changed to 1280x720
2021-01-03 20:08:39.940 BZFlag[5334:69829] INFO: Window 2 shown
2021-01-03 20:08:39.940 BZFlag[5334:69829] INFO: Window 2 gained keyboard focus
2021-01-03 20:08:39.940 BZFlag[5334:69829] INFO: Mouse entered window 2
2021-01-03 20:08:39.940 BZFlag[5334:69829] INFO: Window 2 exposed

Minimize client:

2021-01-03 20:08:52.439 BZFlag[5334:69829] INFO: Window 2 moved to 640,360
2021-01-03 20:08:52.439 BZFlag[5334:69829] INFO: Window 2 size changed to 1280x720
2021-01-03 20:08:52.439 BZFlag[5334:69829] INFO: Window 2 hidden
2021-01-03 20:08:52.439 BZFlag[5334:69829] INFO: Window 2 exposed
2021-01-03 20:08:52.439 BZFlag[5334:69829] INFO: Mouse left window 2
2021-01-03 20:08:52.439 BZFlag[5334:69829] INFO: Window 2 lost keyboard focus
2021-01-03 20:08:52.439 BZFlag[5334:69829] INFO: Window 2 minimized

Click on the application icon (NOT the minimized window icon):

2021-01-03 20:09:11.404 BZFlag[5334:69829] INFO: Window 2 gained keyboard focus
2021-01-03 20:09:11.416 BZFlag[5334:69829] INFO: Mouse entered window 2
2021-01-03 20:09:11.416 BZFlag[5334:69829] INFO: Window 2 size changed to 1280x720
2021-01-03 20:09:11.416 BZFlag[5334:69829] INFO: Window 2 shown
2021-01-03 20:09:11.417 BZFlag[5334:69829] INFO: Window 2 exposed
2021-01-03 20:09:11.417 BZFlag[5334:69829] INFO: Window 2 moved to 640,-360
2021-01-03 20:09:11.417 BZFlag[5334:69829] INFO: Mouse left window 2
2021-01-03 20:09:11.417 BZFlag[5334:69829] INFO: Mouse entered window 2

Minimized the client again:

2021-01-03 20:09:23.540 BZFlag[5334:69829] INFO: Window 2 moved to 640,360
2021-01-03 20:09:23.540 BZFlag[5334:69829] INFO: Window 2 maximized
2021-01-03 20:09:23.540 BZFlag[5334:69829] INFO: Window 2 size changed to 1280x720
2021-01-03 20:09:23.541 BZFlag[5334:69829] INFO: Window 2 hidden
2021-01-03 20:09:23.541 BZFlag[5334:69829] INFO: Window 2 exposed
2021-01-03 20:09:23.541 BZFlag[5334:69829] INFO: Mouse left window 2
2021-01-03 20:09:23.541 BZFlag[5334:69829] INFO: Window 2 lost keyboard focus
2021-01-03 20:09:23.541 BZFlag[5334:69829] INFO: Window 2 minimized

Clicked on the minimized window icon:

2021-01-03 20:09:39.613 BZFlag[5334:69829] INFO: Window 2 gained keyboard focus
2021-01-03 20:09:39.614 BZFlag[5334:69829] INFO: Window 2 moved to 0,0
2021-01-03 20:09:39.614 BZFlag[5334:69829] INFO: Window 2 size changed to 1280x720
2021-01-03 20:09:39.614 BZFlag[5334:69829] INFO: Window 2 shown
2021-01-03 20:09:39.614 BZFlag[5334:69829] INFO: Window 2 exposed
2021-01-03 20:09:39.614 BZFlag[5334:69829] INFO: Mouse entered window 2