Handle lpcbData == NULL case.

reactos/lib/advapi32/reg

diff -u -r1.45 -r1.46
--- reg.c	1 Apr 2004 13:53:08 -0000	1.45
+++ reg.c	3 Apr 2004 13:12:43 -0000	1.46
@@ -1,4 +1,4 @@

-/* $Id: reg.c,v 1.45 2004/04/01 13:53:08 ekohl Exp $

+/* $Id: reg.c,v 1.46 2004/04/03 13:12:43 gvg Exp $

  *
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS system libraries

@@ -2292,13 +2292,16 @@

   RtlCreateUnicodeStringFromAsciiz (&ValueName,
 				    (LPSTR)lpValueName);
 

-  Length = *lpcbData * sizeof(WCHAR);

+  if (NULL != lpcbData)
+    {
+      Length = *lpcbData * sizeof(WCHAR);
+    }

   ErrorCode = RegQueryValueExW (hKey,
 				ValueName.Buffer,
 				lpReserved,
 				&Type,
 				(LPBYTE)ValueData.Buffer,

-				&Length);

+				NULL == lpcbData ? NULL : &Length);

   DPRINT("ErrorCode %lu\n", ErrorCode);
 
   if (ErrorCode == ERROR_SUCCESS ||

@@ -2322,7 +2325,7 @@

 	    }
 	  Length = Length / sizeof(WCHAR);
 	}

-      else

+      else if (lpcbData != NULL)

 	{
 	  Length = min(*lpcbData, Length);
 	  if (ErrorCode == ERROR_SUCCESS && ValueData.Buffer != NULL)