From 3a56c1a0e4f3bb33a4370cc60a1b5ef45250d5dd Mon Sep 17 00:00:00 2001
From: Henri DF <henridf@gmail.com>
Date: Mon, 22 Feb 2016 18:55:11 -0800
Subject: [PATCH] AST: Rule node always has an Output child node

---
 userspace/digwatch/lua/compiler.lua | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/userspace/digwatch/lua/compiler.lua b/userspace/digwatch/lua/compiler.lua
index 81d0065f..2a587f7a 100644
--- a/userspace/digwatch/lua/compiler.lua
+++ b/userspace/digwatch/lua/compiler.lua
@@ -168,6 +168,9 @@ local function outputformat (format)
 end
 
 local function rule(filter, output)
+   if not output then
+      output = outputformat("")
+   end
    return {type = "Rule", filter = filter, output = output}
 end