mods that hopefully work for a TechAge-based pack

mods/techage_modpack/techage/basis/formspec_update.lua

@@ -0,0 +1,52 @@
+--[[
+
+	TechAge
+	=======
+
+	Copyright (C) 2019 Joachim Stolberg
+
+	AGPL v3
+	See LICENSE.txt for more information
+
+	Keep only one formspec active per player
+
+]]--
+
+local P2S = minetest.pos_to_string
+
+local ActiveFormspecs = {}
+local ActivePlayer = {}
+
+
+function techage.is_activeformspec(pos)
+	return ActiveFormspecs[P2S(pos)]
+end
+
+function techage.set_activeformspec(pos, player)
+	local name = player and player:get_player_name()
+	if name then
+		if ActivePlayer[name] then
+			ActiveFormspecs[ActivePlayer[name]] = nil
+		end
+		ActivePlayer[name] = P2S(pos)
+		ActiveFormspecs[P2S(pos)] = true
+	end
+end
+
+function techage.reset_activeformspec(pos, player)
+	local name = player and player:get_player_name()
+	if name then
+		if ActivePlayer[name] then
+			ActiveFormspecs[ActivePlayer[name]] = nil
+			ActivePlayer[name] = nil
+		end
+	end
+end
+
+minetest.register_on_leaveplayer(function(player)
+	local name = player:get_player_name()
+	if ActivePlayer[name] then
+		ActiveFormspecs[ActivePlayer[name]] = nil
+		ActivePlayer[name] = nil
+	end
+end)