Fixed creating fullscreen windows on Steam Link

src/video/SDL_video.c

@@ -1309,11 +1309,6 @@ SDL_UpdateFullscreenMode(SDL_Window * window, SDL_bool fullscreen)
 static void
 SDL_FinishWindowCreation(SDL_Window *window, Uint32 flags)
 {
-    window->windowed.x = window->x;
-    window->windowed.y = window->y;
-    window->windowed.w = window->w;
-    window->windowed.h = window->h;
-
     if (flags & SDL_WINDOW_MAXIMIZED) {
         SDL_MaximizeWindow(window);
     }
@@ -1413,6 +1408,25 @@ SDL_CreateWindow(const char *title, int x, int y, int w, int h, Uint32 flags)
             window->y = bounds.y + (bounds.h - h) / 2;
         }
     }
+    window->windowed.x = window->x;
+    window->windowed.y = window->y;
+    window->windowed.w = window->w;
+    window->windowed.h = window->h;
+
+    if (flags & SDL_WINDOW_FULLSCREEN) {
+        SDL_VideoDisplay *display = SDL_GetDisplayForWindow(window);
+        int displayIndex;
+        SDL_Rect bounds;
+
+        displayIndex = SDL_GetIndexOfDisplay(display);
+        SDL_GetDisplayBounds(displayIndex, &bounds);
+
+        window->x = bounds.x;
+        window->y = bounds.y;
+        window->w = bounds.w;
+        window->h = bounds.h;
+    }
+
     window->flags = ((flags & CREATE_FLAGS) | SDL_WINDOW_HIDDEN);
     window->last_fullscreen_flags = window->flags;
     window->opacity = 1.0f;