pyldb: consistent results in py_ldb_msg_richcmp

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Ralph Boehme <slow@samba.org>

diff --git a/lib/ldb/pyldb.c b/lib/ldb/pyldb.c
index 8acb51705f187fecde752c8c7f7d59609461d13c..9acea901558db21e7019bdca44565cfd3d1f768b 100644 (file)
--- a/lib/ldb/pyldb.c
+++ b/lib/ldb/pyldb.c
@@ -4445,18 +4445,18 @@ static PyObject *py_ldb_msg_richcmp(PyLdbMessageObject *py_msg1,
        PyErr_LDB_MESSAGE_OR_RAISE(py_msg1, msg1);
        PyErr_LDB_MESSAGE_OR_RAISE(py_msg2, msg2);
        /*
-        * FIXME: this can be a non-transitive compare, unsuitable for
-        * sorting.
+        * If the DNs are different, sort by DN.
         *
-        * supposing msg1, msg2, and msg3 have 1, 2, and 3 elements
-        * each. msg2 has a NULL DN, while msg1 has a DN that compares
-        * higher than msg3. Then:
-        *
-        * msg1 < msg2, due to num_elements.
-        * msg2 < msg3, due to num_elements.
-        * msg1 > msg3, due to DNs.
+        * NULL DNs sort to the end. Note that if there are multiple messages
+        * with NULL DNs, they sort normally by the other attributes.
         */
-       if ((msg1->dn != NULL) || (msg2->dn != NULL)) {
+       if (msg1->dn != msg2->dn) {
+               if (msg1->dn == NULL) {
+                       return richcmp(-1, op);
+               }
+               if (msg2->dn == NULL) {
+                       return richcmp(1, op);
+               }
                ret = ldb_dn_compare(msg1->dn, msg2->dn);
                if (ret != 0) {
                        return richcmp(ret, op);