iOS: Fix app orientation when creating a landscape fullscreen window with the device currently in portrait orientation.

src/video/uikit/SDL_uikitwindow.m

@@ -107,6 +107,14 @@ static int SetupWindowData(_THIS, SDL_Window *window, UIWindow *uiwindow, SDL_bo
 
 #if !TARGET_OS_TV
     if (displaydata.uiscreen == [UIScreen mainScreen]) {
+        /* SDL_CreateWindow sets the window w&h to the display's bounds if the
+         * fullscreen flag is set. But the display bounds orientation might not
+         * match what we want, and GetSupportedOrientations call below uses the
+         * window w&h. They're overridden below anyway, so we'll just set them
+         * to the requested size for the purposes of determining orientation. */
+        window->w = window->windowed.w;
+        window->h = window->windowed.h;
+
         NSUInteger orients = UIKit_GetSupportedOrientations(window);
         BOOL supportsLandscape = (orients & UIInterfaceOrientationMaskLandscape) != 0;
         BOOL supportsPortrait = (orients & (UIInterfaceOrientationMaskPortrait|UIInterfaceOrientationMaskPortraitUpsideDown)) != 0;