SDL: wayland: Ignore stateless/sizeless configs when starting in fullscreen mode

SDL Commits
1 
From ae7ee2a59c8d41d67c6bc80f25b6e52670dddbbf Mon Sep 17 00:00:00 2001
From: Ethan Lee <[EMAIL REDACTED]>
Date: Wed, 11 Aug 2021 09:59:43 -0400
Subject: [PATCH] wayland: Ignore stateless/sizeless configs when starting in
 fullscreen mode

---
 src/video/wayland/SDL_waylandwindow.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/video/wayland/SDL_waylandwindow.c b/src/video/wayland/SDL_waylandwindow.c
index 025dd30ee..451d33b76 100644
--- a/src/video/wayland/SDL_waylandwindow.c
+++ b/src/video/wayland/SDL_waylandwindow.c
@@ -219,9 +219,15 @@ handle_configure_xdg_toplevel(void *data,
 
             /* Foolishly do what the compositor says here. If it's wrong, don't
              * blame us, we were explicitly instructed to do this.
+             *
+             * UPDATE: Nope, we can't actually do that, the compositor may give
+             * us a completely stateless, sizeless configure, with which we have
+             * to enforce our own state anyway.
              */
-            window->w = width;
-            window->h = height;
+            if (width != 0 && height != 0) {
+                window->w = width;
+                window->h = height;
+            }
 
             /* This part is good though. */
             if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {