ldapobject: store message id for exceptions raised from result4()

krisztian-kovacs · krisztian-kovacs · commit d3d0dc366f66 · 2020-02-13T15:56:09.000+01:00
Otherwise calling result4() can return exceptions like NO_SUCH_OBJECT or
COMPARE_TRUE without the caller being able to find the matching asynchronous
operation that failed.

This change adds the message id as an argument to the exception.
diff --git a/Doc/reference/ldap.rst b/Doc/reference/ldap.rst
@@ -321,6 +321,14 @@ The module defines the following exceptions:
    is set to a truncated form of the name provided or alias dereferenced
    for the lowest entry (object or alias) that was matched.
 
+   For use in asynchronous operations an optional field :py:const:`msg_id` is
+   also set in the dictionary in cases where the exception can be associated
+   with a request. This can be used in asynchronous code where
+   :py:meth:`result()` returns an exception that is effectively the result of a
+   previously started asynchronous operation. For example, this is the case for
+   asynchronous (:py:meth:`compare()`), where the boolean result is always
+   raised as an exception (:py:exc:`COMPARE_TRUE` or :py:exc:`COMPARE_FALSE`).
+
 
 .. py:exception:: ADMINLIMIT_EXCEEDED
 
diff --git a/Modules/LDAPObject.c b/Modules/LDAPObject.c
@@ -1174,7 +1174,7 @@ l_ldap_result4(LDAPObject *self, PyObject *args)
         ldap_controls_free(serverctrls);
         ldap_msgfree(msg);
         Py_XDECREF(valuestr);
-        return LDAPerror(self->ldap, e);
+        return LDAPerror_with_message_id(self->ldap, e, res_msgid);
     }
 
     if (!(pyctrls = LDAPControls_to_List(serverctrls))) {
@@ -1186,7 +1186,7 @@ l_ldap_result4(LDAPObject *self, PyObject *args)
         ldap_controls_free(serverctrls);
         ldap_msgfree(msg);
         Py_XDECREF(valuestr);
-        return LDAPerror(self->ldap, "LDAPControls_to_List");
+        return LDAPerror_with_message_id(self->ldap, "LDAPControls_to_List", res_msgid);
     }
     ldap_controls_free(serverctrls);
 
diff --git a/Modules/constants.c b/Modules/constants.c
@@ -49,6 +49,13 @@ LDAPerr(int errnum)
 /* Convert an LDAP error into an informative python exception */
 PyObject *
 LDAPerror(LDAP *l, char *msg)
+{
+    return LDAPerror_with_message_id(l, msg, -1);
+}
+
+/* Convert an LDAP error into an informative python exception containing the message id */
+PyObject *
+LDAPerror_with_message_id(LDAP *l, char *msg, int msg_id)
 {
     if (l == NULL) {
         PyErr_SetFromErrno(LDAPexception_class);
@@ -93,6 +100,13 @@ LDAPerror(LDAP *l, char *msg)
             Py_XDECREF(pyerrno);
         }
 
+        if (msg_id > 0) {
+            PyObject *pymsg_id = PyInt_FromLong(msg_id);
+            if (pymsg_id)
+                PyDict_SetItemString(info, "msg_id", pymsg_id);
+            Py_XDECREF(pymsg_id);
+        }
+
         if (ldap_get_option(l, LDAP_OPT_MATCHED_DN, &matched) >= 0
             && matched != NULL) {
             if (*matched != '\0') {
diff --git a/Modules/constants.h b/Modules/constants.h
@@ -12,6 +12,7 @@ extern PyObject *LDAPconstant(int);
 
 extern PyObject *LDAPexception_class;
 extern PyObject *LDAPerror(LDAP *, char *msg);
+extern PyObject *LDAPerror_with_message_id(LDAP *, char *msg, int msg_id);
 PyObject *LDAPerr(int errnum);
 
 #ifndef LDAP_CONTROL_PAGE_OID
diff --git a/Tests/t_ldapobject.py b/Tests/t_ldapobject.py
@@ -673,6 +673,20 @@ def test_compare_s_invalidattr(self):
         with self.assertRaises(ldap.UNDEFINED_TYPE):
             result = l.compare_s('cn=Foo1,%s' % base, 'invalidattr', b'invalid')
 
+    def test_compare_true_exception_contains_message_id(self):
+        base = self.server.suffix
+        l = self._ldap_conn
+        msg_id = l.compare('cn=Foo1,%s' % base, 'cn', b'Foo1')
+        with self.assertRaises(ldap.COMPARE_TRUE) as cm:
+            l.result()
+        self.assertEqual(cm.exception.args[0]["msg_id"], msg_id)
+
+    def test_async_search_no_such_object_exception_contains_message_id(self):
+        msg_id = self._ldap_conn.search("CN=XXX", ldap.SCOPE_SUBTREE)
+        with self.assertRaises(ldap.NO_SUCH_OBJECT) as cm:
+            self._ldap_conn.result()
+        self.assertEqual(cm.exception.args[0]["msg_id"], msg_id)
+
 
 class Test01_ReconnectLDAPObject(Test00_SimpleLDAPObject):
     """
