auth: Do not forward empty "master" passdb field

diff --git a/src/auth/auth-request-handler.c b/src/auth/auth-request-handler.c
index 5f7a5a69c2c03ddbdbf0e6b4dc13fe5245b3d6cb..d4bf53c27657a929b7813ee845ef7ac33c41e115 100644 (file)
--- a/src/auth/auth-request-handler.c
+++ b/src/auth/auth-request-handler.c
@@ -204,7 +204,8 @@ auth_str_append_extra_fields(struct auth_request *request, string_t *dest)
                                              request->mech_password);
                }
                if (fields->master_user != NULL &&
-                   !auth_fields_exists(fields->extra_fields, "master")) {
+                   !auth_fields_exists(fields->extra_fields, "master") &&
+                   *fields->master_user != '\0') {
                        /* the master username needs to be forwarded */
                        auth_str_add_keyvalue(dest, "master",
                                              fields->master_user);