Fixed showing and hiding fullscreen windows

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%404457

src/video/SDL_sysvideo.h

@@ -182,7 +182,6 @@ struct SDL_VideoDisplay
     int num_render_drivers;
     SDL_RenderDriver *render_drivers;
 
-    int num_windows;
     SDL_Window *windows;
     SDL_Window *fullscreen_window;
 

src/video/SDL_video.c

@@ -772,7 +772,6 @@ static void
 SDL_UpdateFullscreenMode(SDL_Window * window, SDL_bool attempt)
 {
     SDL_VideoDisplay *display = window->display;
-    int i;
 
     /* See if we're already processing a window */
     if (display->updating_fullscreen) {
@@ -799,8 +798,8 @@ SDL_UpdateFullscreenMode(SDL_Window * window, SDL_bool attempt)
 
     if (FULLSCREEN_VISIBLE(window)) {
         /* Hide any other fullscreen windows */
-        for (i = 0; i < display->num_windows; ++i) {
-            SDL_Window *other = &display->windows[i];
+        SDL_Window *other;
+        for (other = display->windows; other; other = other->next) {
             if (other != window && FULLSCREEN_VISIBLE(other)) {
                 SDL_MinimizeWindow(other);
             }
@@ -810,8 +809,7 @@ SDL_UpdateFullscreenMode(SDL_Window * window, SDL_bool attempt)
     display->updating_fullscreen = SDL_FALSE;
 
     /* See if there are any fullscreen windows */
-    for (i = 0; i < display->num_windows; ++i) {
-        window = &display->windows[i];
+    for (window = display->windows; window; window = window->next) {
         if (FULLSCREEN_VISIBLE(window)) {
             SDL_DisplayMode fullscreen_mode;
             if (SDL_GetWindowDisplayMode(window, &fullscreen_mode) == 0) {