[weiden] 25648: Make RtlEqualPrefixSid portable

Author: weiden
Date: Sat Jan 27 17:06:01 2007
New Revision: 25648
URL: http://svn.reactos.org/svn/reactos?rev=25648&view=rev
Log:
Make RtlEqualPrefixSid portable
Modified:
    trunk/reactos/lib/rtl/sid.c
Modified: trunk/reactos/lib/rtl/sid.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/rtl/sid.c?rev=25648&am…
==============================================================================
--- trunk/reactos/lib/rtl/sid.c (original)
+++ trunk/reactos/lib/rtl/sid.c Sat Jan 27 17:06:01 2007
@@ -303,14 +303,22 @@
 RtlEqualPrefixSid(IN PSID Sid1_,
                   IN PSID Sid2_)
 {
-  PISID Sid1 =  Sid1_;
-  PISID Sid2 =  Sid2_;
-
-  PAGED_CODE_RTL();
-
-   return(Sid1->SubAuthorityCount == Sid2->SubAuthorityCount &&
-          !RtlCompareMemory(Sid1, Sid2,
-                            (Sid1->SubAuthorityCount - 1) * sizeof(DWORD) + 8));
+   PISID Sid1 =  Sid1_;
+   PISID Sid2 =  Sid2_;
+   SIZE_T SidLen;
+
+   PAGED_CODE_RTL();
+
+   if (Sid1->SubAuthorityCount == Sid2->SubAuthorityCount)
+   {
+      SidLen = FIELD_OFFSET(SID,
+                            SubAuthority[Sid1->SubAuthorityCount]);
+      return RtlCompareMemory(Sid1,
+                              Sid2,
+                              SidLen) == SidLen;
+   }
+
+   return FALSE;
 }