auth: Avoid assert-crash if returning ":default" passdb or userdb extra field

diff --git a/src/auth/auth-request.c b/src/auth/auth-request.c
index aa249654be7616b3b63b3f7bd1267ef88b8669f6..d7dbd259263a5fd1cf96cbf23a6563e4f2bf0e7e 100644 (file)
--- a/src/auth/auth-request.c
+++ b/src/auth/auth-request.c
@@ -1998,6 +1998,8 @@ void auth_request_set_field(struct auth_request *request,
        if (name_len > 8 && strcmp(name+name_len-8, ":default") == 0) {
                /* set this field only if it hasn't been set before */
                name = t_strndup(name, name_len-8);
+               if (name[0] == '\0')
+                       return; /* ":default" is invalid */
                if (auth_fields_exists(request->fields.extra_fields, name))
                        return;
        } else if (name_len > 7 && strcmp(name+name_len-7, ":remove") == 0) {
@@ -2228,6 +2230,8 @@ void auth_request_set_userdb_field(struct auth_request *request,
                name = t_strndup(name, name_len-8);
                if (auth_fields_exists(request->fields.userdb_reply, name))
                        return;
+               if (name[0] == '\0')
+                       return; /* ":default" is invalid */
        } else if (name_len > 7 && strcmp(name+name_len-7, ":remove") == 0) {
                /* remove this field entirely */
                name = t_strndup(name, name_len-7);