From 30c6b5c41e822e9f0c6fe1b2264aa020615aca6d Mon Sep 17 00:00:00 2001
From: Paul Gofman <pgofman@codeweavers.com>
Date: Fri, 16 Sep 2022 15:43:47 -0500
Subject: [PATCH] lsteamclient: Return NULL from
 manual_convert_SteamAPI_CheckCallbackRegistered_t() if win_func is NULL.

CW-Bug-Id: #21313
---
 lsteamclient/steamclient_wrappers.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lsteamclient/steamclient_wrappers.c b/lsteamclient/steamclient_wrappers.c
index f840752a..94e60ed8 100644
--- a/lsteamclient/steamclient_wrappers.c
+++ b/lsteamclient/steamclient_wrappers.c
@@ -348,6 +348,8 @@ static uint32 lin_SteamAPI_CheckCallbackRegistered_t(int cb)
 
 void *manual_convert_SteamAPI_CheckCallbackRegistered_t(void *win_func)
 {
-    stored_SteamAPI_CheckCallbackRegistered_t = (void*)win_func;
+    if (!(stored_SteamAPI_CheckCallbackRegistered_t = (void*)win_func))
+        return NULL;
+
     return &lin_SteamAPI_CheckCallbackRegistered_t;
 }