Replace deprecated meta:set_string(*, nil) calls

icta_controller/controller.lua

@@ -379,7 +379,6 @@ minetest.register_node("techage:ta4_icta_controller", {
 		meta:set_string("number", number)
 		meta:set_int("state", techage.STOPPED)
 		meta:set_string("formspec", techage.formspecRules(meta, fs_data, sOUTPUT))
-		--meta:set_string("formspec", techage.cond_formspec(1, 1, nil))
 		meta:set_string("infotext", "TA4 ICTA Controller "..number..": stopped")
 	end,
 

logic/button.lua

@@ -202,7 +202,7 @@ local function on_receive_fields(pos, formname, fields, player)
 	local meta = M(pos)
 	logic.infotext(meta, NDEF(pos).description)
 	if fields.exit then
-		meta:set_string("formspec", nil)
+		meta:set_string("formspec", "")
 		meta:set_string("fixed" , "true")
 	else
 		meta:set_string("formspec", formspec(meta))

logic/programmer.lua

@@ -25,7 +25,7 @@ local function join_to_string(tbl)
 end
 
 local function reset_programmer(itemstack, user, pointed_thing)
-	user:get_meta():set_string("techage_prog_numbers", nil)
+	user:get_meta():set_string("techage_prog_numbers", "")
 	minetest.chat_send_player(user:get_player_name(), S("[TechAge Programmer] programmer reset"))
 	return itemstack
 end
@@ -53,7 +53,7 @@ local function program_numbers(itemstack, placer, pointed_thing)
 	if pos then
 		local meta = M(pos)
 		local numbers = minetest.deserialize(placer:get_meta():get_string("techage_prog_numbers")) or {}
-		placer:get_meta():set_string("techage_prog_numbers", nil)
+		placer:get_meta():set_string("techage_prog_numbers", "")
 		local player_name = placer:get_player_name()
 		if meta and meta:get_string("owner") ~= player_name then
 			minetest.chat_send_player(player_name, S("[TechAge Programmer] foreign or unknown node!"))

logic/terminal.lua

@@ -429,7 +429,7 @@ techage.register_node({"techage:terminal2"}, {
 		local number = meta:get_string("number") or ""
 		if number ~= "" then
 			meta:set_string("node_number", number)
-			meta:set_string("number", nil)
+			meta:set_string("number", "")
 		end
 	end,
 })

move_controller/doorblock.lua

@@ -75,7 +75,7 @@ for idx,pgn in ipairs(tPgns) do
 				minetest.swap_node(pos, node)
 			end
 			if fields.exit then
-				meta:set_string("formspec", nil)
+				meta:set_string("formspec", "")
 				local number = techage.add_node(pos, node.name)
 				meta:set_string("infotext", S("TechAge Door Block").." "..number)
 			end

move_controller/gateblock.lua

@@ -61,7 +61,7 @@ for idx,pgn in ipairs(tPgns) do
 				minetest.swap_node(pos, node)
 			end
 			if fields.exit then
-				meta:set_string("formspec", nil)
+				meta:set_string("formspec", "")
 				local number = techage.add_node(pos, node.name)
 				meta:set_string("infotext", S("TechAge Gate Block").." "..number)
 			end