SDL: x11: Check for a valid video device pointer before dereferencing the name

SDL Commits
1 
From 95c0b49de080e27ee2fae01e0dca2793971ad51d Mon Sep 17 00:00:00 2001
From: Frank Praznik <[EMAIL REDACTED]>
Date: Sun, 19 Oct 2025 18:39:44 -0400
Subject: [PATCH] x11: Check for a valid video device pointer before
 dereferencing the name

---
 src/video/x11/SDL_x11messagebox.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/video/x11/SDL_x11messagebox.c b/src/video/x11/SDL_x11messagebox.c
index b85d1634881e5..041f41d36dae3 100644
--- a/src/video/x11/SDL_x11messagebox.c
+++ b/src/video/x11/SDL_x11messagebox.c
@@ -307,7 +307,7 @@ static bool X11_ShowMessageBoxImpl(const SDL_MessageBoxData *messageboxdata, int
     }
 
     /* Create window */
-    if (messageboxdata->window && SDL_strcmp(video->name, "x11") == 0) {
+    if (messageboxdata->window && video && SDL_strcmp(video->name, "x11") == 0) {
         // Only use the window as a parent if it is from the X11 driver.
         parent_window = messageboxdata->window;
     }