I think you were passing the name of the SID, rather than the DOM_SID

pointer itself.  (Whatever that is.... ;-)
(This used to be commit 1393c7c4ede1d6d624c3f5d0bfa4c18b0c6dc27f)

diff --git a/source3/nsswitch/winbindd_util.c b/source3/nsswitch/winbindd_util.c
index 457a914e5caed193f3ce2c0e8e6a0f603b61bf22..9c10e1b2bd1984cf666f94c6f6849bcf9b663e63 100644 (file)
--- a/source3/nsswitch/winbindd_util.c
+++ b/source3/nsswitch/winbindd_util.c
@@ -486,7 +486,7 @@ BOOL winbindd_lookup_name_by_sid(DOM_SID *sid, fstring name, enum SID_NAME_USE *
                fstring sidstr;
 
                sid_to_string(sidstr, sid);
-               store_name_by_sid_in_cache(sidstr, "", SID_NAME_USE_NONE);
+               store_name_by_sid_in_cache(sid, "", SID_NAME_USE_NONE);
        }
 
        rv = NT_STATUS_IS_OK(result);