Don't resize fullscreen windows when hiding or minimizing them (thanks …

…@madewokherd!)

This has the benefit of window previews (mousing over the icon) having the correct size and contents.

Fixes #5320

src/video/windows/SDL_windowswindow.c

@@ -734,6 +734,13 @@ WIN_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display,
     int x, y;
     int w, h;
 
+    if (!fullscreen && (window->flags & (SDL_WINDOW_FULLSCREEN|SDL_WINDOW_FULLSCREEN_DESKTOP)) != 0) {
+        /* Resizing the window on hide causes problems restoring it in Wine, and it's unnecessary.
+         * Also, Windows would preview the minimized window with the wrong size.
+         */
+        return;
+    }
+
     if (SDL_ShouldAllowTopmost() && ((window->flags & (SDL_WINDOW_FULLSCREEN|SDL_WINDOW_INPUT_FOCUS)) == (SDL_WINDOW_FULLSCREEN|SDL_WINDOW_INPUT_FOCUS) || window->flags & SDL_WINDOW_ALWAYS_ON_TOP)) {
         top = HWND_TOPMOST;
     } else {