One liner from Alex_Ionescu that fixes svn hanging during checkout or update.

Modified: trunk/reactos/lib/advapi32/sec/misc.c

--- trunk/reactos/lib/advapi32/sec/misc.c	2005-10-20 16:49:00 UTC (rev 18638)
+++ trunk/reactos/lib/advapi32/sec/misc.c	2005-10-20 17:48:19 UTC (rev 18639)
@@ -1203,7 +1203,7 @@

             ppsidOwner = NULL;
         }
         if ((SecurityInfo & GROUP_SECURITY_INFORMATION) &&

-            *ppsidGroup != NULL)

+           (ppsidGroup) && (*ppsidGroup)) 

         {
             *ppsidGroup = NULL;
         }