From 1669cfd4510a2dbb2ca3c754b414ae8c976ceca1 Mon Sep 17 00:00:00 2001
From: thetaepsilon-gamedev <thetaepsilon-gamedev@noreply.users.github.com>
Date: Sat, 7 Oct 2017 15:42:00 +0100
Subject: [PATCH] new flow logic: flowable_node_registry_install.lua: add
 duplicate registration guard for register.output()

---
 new_flow_logic/flowable_node_registry_install.lua | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/new_flow_logic/flowable_node_registry_install.lua b/new_flow_logic/flowable_node_registry_install.lua
index 650d1da..07001ef 100644
--- a/new_flow_logic/flowable_node_registry_install.lua
+++ b/new_flow_logic/flowable_node_registry_install.lua
@@ -71,6 +71,9 @@ end
 -- if finite mode is on, upper is ignored and lower is used to determine whether to run outputfn;
 -- cleanupfn is ignored in this mode as finite mode assumes something causes water to move itself.
 register.output = function(nodename, upper, lower, outputfn)
+	if pipeworks.flowables.outputs.list[nodename] then
+		error("pipeworks.flowables.outputs duplicate registration!")
+	end
 	checkbase(nodename)
 	pipeworks.flowables.outputs.list[nodename] = { threshold=threshold, outputfn=outputfn }
 	if pipeworks.toggles.pressure_logic then