--- source/passdb/lookup_sid.c.orig	2007-03-16 12:47:29.000000000 +0100
+++ source/passdb/lookup_sid.c	2007-03-16 13:50:13.000000000 +0100
@@ -381,12 +381,20 @@
 
 	if (!winbind_lookup_rids(tmp_ctx, domain_sid, num_rids, rids,
 				domain_name, &my_names, &my_types)) {
-	for (i=0; i<num_rids; i++) {
+		*domain_name = "";
+		for (i=0; i<num_rids; i++) {
+			names[i] = "";
 			types[i] = SID_NAME_UNKNOWN;
 		}
+		TALLOC_FREE(tmp_ctx);
 		return True;
 	}
 
+	if (!(*domain_name = talloc_strdup(mem_ctx, *domain_name))) {
+		TALLOC_FREE(tmp_ctx);
+		return False;
+	}
+
 	/*
 	 * winbind_lookup_rids allocates its own array. We've been given the
 	 * array, so copy it over