# HG changeset patch
# User Kim Alvefur <zash@zash.se>
# Date 1723993110 -7200
# Node ID 2fb79fe5439051db94d9de3e1152bac8bd89209a
# Parent  a97c11584042ac7dd1375af5112186b5e9c8eb0e
core.moduleapi: Default labels to empty list to fix error if omitted

In a host-scoped module in the `if is_scoped` clause the resulting
`array:append(nil)` call throws.

diff -r a97c11584042 -r 2fb79fe54390 core/moduleapi.lua
--- a/core/moduleapi.lua	Thu Aug 08 19:18:22 2024 +0200
+++ b/core/moduleapi.lua	Sun Aug 18 16:58:30 2024 +0200
@@ -558,6 +558,7 @@
 function api:metric(type_, name, unit, description, label_keys, conf)
 	local metric = require "core.statsmanager".metric;
 	local is_scoped = self.host ~= "*"
+	label_keys = label_keys or {};
 	if is_scoped then
 		-- prepend `host` label to label keys if this is not a global module
 		local orig_labels = label_keys