x11 doesn't respect earlier resize requests when leaving fullscreen.

[icculus]

This appears to be an SDL2 bug...this code:

https://github.com/libsdl-org/sdl12-compat/blob/4e4527a123fb99a1677055d89c5fc74323ddc4d8/src/SDL12_compat.c#L5074-L5075

If I add a copy/paste of the SDL_SetWindowSize() call after the SDL_SetWindowFullscreen() call, then it works correctly, like the X11 SDL2 backend failed to respect the window size change that happened before leaving fullscreen.

Originally posted by @icculus in libsdl-org/sdl12-compat#148 (comment)

[icculus]

I think this is an SDL2 bug; I'll write up a simple reproduction case soon to verify.

[icculus]

I need to check if this is an SDL issue (maybe it ignores/loses size change requests while fullscreen), or an X11 async issue.

[icculus]

I can't reproduce with this program:

#include "SDL.h"

int main(int argc, char** argv)
{
    SDL_Init(SDL_INIT_VIDEO);
    SDL_Window* win = SDL_CreateWindow("test", 0, 0, 1024, 768, SDL_WINDOW_FULLSCREEN);
    SDL_Event e;

    int done = 0;
    while (!done) {
        while (SDL_PollEvent(&e)) {
            if ((e.type == SDL_KEYDOWN) && (e.key.keysym.sym == SDLK_f)) {
                SDL_SetWindowSize(win, 320, 240);
                SDL_SetWindowFullscreen(win, 0);
            } else if (e.type == SDL_QUIT) {
                done = 1;
                break;
            }
        }
        SDL_Delay(100);
    }

    SDL_DestroyWindow(win);
    SDL_Quit();
    return 0;
}

I can't reproduce with SDL 2.0.16 through 2.0.20 either, using FULLSCREEN or FULLSCREEN_DESKTOP.

I've upgraded this machine to a newer Ubuntu install since then, so it's possible that it was fixed in a later x.org or Gnome (or it is an IceWM bug, which I was often using on the old install due to an unrelated Gnome bug).

So I'm going to call this okay until someone else complains.