diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index c6273aa33..53a003a95 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,9 @@
+2012-03-02  Corinna Vinschen  <corinna@vinschen.de>
+
+	* flock.cc (allow_others_to_sync): Reorder conditional expression to
+	check for DACL presence first, since otherwise dacl pointer value is
+	undefined.  Add comment.
+
 2012-03-02  Corinna Vinschen  <corinna@vinschen.de>
 
 	* flock.cc (allow_others_to_sync): Use RtlGetDaclSecurityDescriptor
diff --git a/winsup/cygwin/flock.cc b/winsup/cygwin/flock.cc
index c66891a35..176e4869e 100644
--- a/winsup/cygwin/flock.cc
+++ b/winsup/cygwin/flock.cc
@@ -178,16 +178,16 @@ allow_others_to_sync ()
      is in self-relative format. */
   BOOLEAN present, defaulted;
   RtlGetDaclSecurityDescriptor (sd, &present, &dacl, &defaulted);
-  if (dacl == NULL) /* Everyone has all access anyway */
-    {
-      done = true;
-      return;
-    }
-  else if (!present)
+  if (!present) /* If so, dacl has undefined value. */
     {
       dacl = (PACL) (sd + 1);
       RtlCreateAcl (dacl, MAX_PROCESS_SD_SIZE - sizeof *sd, ACL_REVISION);
     }
+  else if (dacl == NULL) /* Everyone has all access anyway */
+    {
+      done = true;
+      return;
+    }
   else
     {
       dacl->AclSize = MAX_PROCESS_SD_SIZE - ((PBYTE) dacl - (PBYTE) sd);