supply_converter: avoid crashes caused by wrong digiline message types (#397)

DS

2017-10-31 37d49142cfebc821bc6fd994fb7e7ae8dba9d66d

supply_converter: avoid crashes caused by wrong digiline message types (#397)

 technic/machines/supply_converter.lua

@@ -72,6 +72,9 @@
    receptor = {action = function() end},
    effector = {
        action = function(pos, node, channel, msg)
            if type(msg) ~= "string" then
                return
            end
            local meta = minetest.get_meta(pos)
            if channel ~= meta:get_string("channel") then
                return
@@ -90,7 +93,7 @@
                meta:set_int("enabled", 1)
            elseif msg == "toggle" then
                local onn = meta:get_int("enabled")
                onn = -(onn-1) -- Mirror onn with pivot 0.5, so switch between 1 and 0.
                onn = 1-onn -- Mirror onn with pivot 0.5, so switch between 1 and 0.
                meta:set_int("enabled", onn)
            elseif msg:sub(1, 5) == "power" then
                local power = tonumber(msg:sub(7))
@@ -103,6 +106,8 @@
                meta:set_int("power", power)
            elseif msg:sub(1, 12) == "mesecon_mode" then
                meta:set_int("mesecon_mode", tonumber(msg:sub(14)))
            else
                return
            end
            set_supply_converter_formspec(meta)
        end