= Description

SDL_DisplayMode returned by SDL_GetDisplayMode reports mode.format as 0 when using Wayland backend (SDL_VIDEODRIVER=wayland). Format is reported properly by X11 backend.

= Environment

Fedora 25 running Gnome Wayland session.

Name        : gnome-shell
Arch        : x86_64
Epoch       : 0
Version     : 3.22.2
Release     : 2.fc25

Name        : SDL2
Arch        : x86_64
Epoch       : 0
Version     : 2.0.5
Release     : 2.fc25

= Output 

X11 Backend Output:

Mode 1920 1080 0x16161804 60

Wayland Backend Output:

Mode 1920 1080 0000000000 60

= Test Driver

#include <stdio.h>
#include <SDL2/SDL.h>

void dump_disp_mode(SDL_DisplayMode &mode) {
  printf("Mode %d %d %#010x %d\n",
         mode.w,
         mode.h,
         mode.format,
         mode.refresh_rate);
}

int test_sdl() {
  int ret;

  ret = SDL_InitSubSystem(SDL_INIT_VIDEO);
  if (ret < 0) {
    fprintf(stderr, "Failed to init SDL video: %s\n", SDL_GetError());
    return 1;
  }

  SDL_DisplayMode mode;
  ret = SDL_GetDesktopDisplayMode(0, &mode);
  if (ret < 0) {
    fprintf(stderr, "Failed to get desktop display mode: %s\n", SDL_GetError());
    return 1;
  }
  dump_disp_mode(mode);

  int modes_num = SDL_GetNumDisplayModes(0);
  for (int i = 0; i < modes_num; i++) {
    ret = SDL_GetDisplayMode(0, i, &mode);
    if (ret < 0) {
      fprintf(stderr, "Failed to get display mode: %s\n", SDL_GetError());
      return 1;
    }
    dump_disp_mode(mode);
  }

  SDL_QuitSubSystem(SDL_INIT_VIDEO);
}

int main(int argc, char **argv) {
  test_sdl();
  return 0;
}