SDL: wayland: Read `window` data only if `window` is valid

SDL Commits
1 
From 70a41f9bc200f6358ec225545243e8a24eccbeb7 Mon Sep 17 00:00:00 2001
From: Guldoman <[EMAIL REDACTED]>
Date: Tue, 1 Nov 2022 09:59:16 +0100
Subject: [PATCH] wayland: Read `window` data only if `window` is valid

---
 src/video/wayland/SDL_waylandevents.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/video/wayland/SDL_waylandevents.c b/src/video/wayland/SDL_waylandevents.c
index 5d8cdb1fd220..00563c8f1252 100644
--- a/src/video/wayland/SDL_waylandevents.c
+++ b/src/video/wayland/SDL_waylandevents.c
@@ -590,11 +590,11 @@ pointer_handle_button_common(struct SDL_WaylandInput *input, uint32_t serial,
                              uint32_t time, uint32_t button, uint32_t state_w)
 {
     SDL_WindowData *window = input->pointer_focus;
-    SDL_VideoData *viddata = window->waylandData;
     enum wl_pointer_button_state state = state_w;
     uint32_t sdl_button;
 
     if (window) {
+        SDL_VideoData *viddata = window->waylandData;
         switch (button) {
             case BTN_LEFT:
                 sdl_button = SDL_BUTTON_LEFT;