From 6318e47bb9a7598eec633ff26b31b237b4b414bc Mon Sep 17 00:00:00 2001
From: Giannis Adamopoulos <gadamopoulos@reactos.org>
Date: Mon, 15 Jan 2018 12:45:41 +0200
Subject: [PATCH] [USER32] InternalGetWindowText: Write to caller's buffer only
 when one was provided. CORE-13614

---
 win32ss/user/user32/windows/window.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/win32ss/user/user32/windows/window.c b/win32ss/user/user32/windows/window.c
index fd006481d1c..388ef25bb10 100644
--- a/win32ss/user/user32/windows/window.c
+++ b/win32ss/user/user32/windows/window.c
@@ -1799,7 +1799,7 @@ int WINAPI
 InternalGetWindowText(HWND hWnd, LPWSTR lpString, int nMaxCount)
 {
     INT Ret = NtUserInternalGetWindowText(hWnd, lpString, nMaxCount);
-    if (Ret == 0)
+    if (Ret == 0 && lpString)
         *lpString = L'\0';
     return Ret;
 }