Compat shim for minetest.swap_node, lightstone conducts from the bottom.

mesecons/legacy.lua

+minetest.swap_node = minetest.swap_node or function(pos, node)
+	local data = minetest.get_meta(pos):to_table()
+	minetest.add_node(pos, node)
+	minetest.get_meta(pos):from_table(data)
+end
\ No newline at end of file

mesecons_lightstone/init.lua

+local lightstone_rules = {
+	{x=0,  y=0,  z=-1},
+	{x=1,  y=0,  z=0},
+	{x=-1, y=0,  z=0},
+	{x=0,  y=0,  z=1},
+	{x=1,  y=1,  z=0},
+	{x=1,  y=-1, z=0},
+	{x=-1, y=1,  z=0},
+	{x=-1, y=-1, z=0},
+	{x=0,  y=1,  z=1},
+	{x=0,  y=-1, z=1},
+	{x=0,  y=1,  z=-1},
+	{x=0,  y=-1, z=-1},
+	{x=0,  y=-1, z=0},
+}
+
 function mesecon:lightstone_add(name, base_item, texture_off, texture_on)
 	minetest.register_node("mesecons_lightstone:lightstone_" .. name .. "_off", {
-	tiles = {texture_off},
-	groups = {cracky=2, mesecon_effector_off = 1, mesecon = 2},
-	description=name.." Lightstone",
-	sounds = default.node_sound_stone_defaults(),
-	mesecons = {effector = {
-		action_on = function (pos, node)
-			minetest.swap_node(pos, {name = "mesecons_lightstone:lightstone_" .. name .. "_on", param2 = node.param2})
-		end
-	}}
-    })
+		tiles = {texture_off},
+		groups = {cracky=2, mesecon_effector_off = 1, mesecon = 2},
+		description=name.." Lightstone",
+		sounds = default.node_sound_stone_defaults(),
+		mesecons = {effector = {
+			rules = lightstone_rules,
+			action_on = function (pos, node)
+				minetest.swap_node(pos, {name = "mesecons_lightstone:lightstone_" .. name .. "_on", param2 = node.param2})
+			end,
+		}}
+	})
 	minetest.register_node("mesecons_lightstone:lightstone_" .. name .. "_on", {
 	tiles = {texture_on},
 	groups = {cracky=2,not_in_creative_inventory=1, mesecon = 2},
@@ -17,9 +34,10 @@ function mesecon:lightstone_add(name, base_item, texture_off, texture_on)
 	light_source = LIGHT_MAX-2,
 	sounds = default.node_sound_stone_defaults(),
 	mesecons = {effector = {
+		rules = lightstone_rules,
 		action_off = function (pos, node)
 			minetest.swap_node(pos, {name = "mesecons_lightstone:lightstone_" .. name .. "_off", param2 = node.param2})
-		end
+		end,
 	}}
 	})