Merge https://github.com/minetest-mods/mesecons into HEAD

mesecons_lightstone/doc/lightstone_blue/description.html

 Effector, glows blue when powered.
+It works in an inactive block.

mesecons_lightstone/doc/lightstone_darkgrey/description.html

 Effector, glows dark grey when powered.
+It works in an inactive block.

mesecons_lightstone/doc/lightstone_green/description.html

 Effector, glows green when powered.
+It works in an inactive block.

mesecons_lightstone/doc/lightstone_lightgrey/description.html

 Effector, glows light grey when powered.
+It works in an inactive block.

mesecons_lightstone/doc/lightstone_red/description.html

 Effector, glows red when powered.
+It works in an inactive block.

mesecons_lightstone/doc/lightstone_yellow/description.html

 Effector, glows yellow when powered.
+It works in an inactive block.

mesecons_luacontroller/doc/luacontroller/description.html

 The Luacontroller is an advanced programmable component.
 You can simply code it in the language Mesecons uses itself: Lua!
 All the code runs in a sandbox, so it's completely safe (but I won't guarantee that for absolute certainty!).
+It works fine in an unloaded block, loading the block when the program needs to run.
+Events are properly delivered after a server restart.
 
 <a href="http://mesecons.net/luacontroller/">Documentation is available here!</a>

mesecons_luacontroller/init.lua

@@ -266,32 +266,45 @@ local function remove_functions(x)
 	return x
 end
 
--- itbl: Flat table of functions to run after sandbox cleanup, used to prevent various security hazards
-local function get_interrupt(pos, itbl, send_warning)
-	-- iid = interrupt id
-	local function interrupt(time, iid)
-		-- NOTE: This runs within string metatable sandbox, so don't *rely* on anything of the form (""):y
-		-- Hence the values get moved out. Should take less time than original, so totally compatible
-		if type(time) ~= "number" then return end
-		table.insert(itbl, function ()
-			-- Outside string metatable sandbox, can safely run this now
-			local luac_id = minetest.get_meta(pos):get_int("luac_id")
-			-- Check if IID is dodgy, so you can't use interrupts to store an infinite amount of data.
-			-- Note that this is safe from alter-after-free because this code gets run after the sandbox has ended.
-			-- This runs outside of the timer and *shouldn't* harm perf. unless dodgy data is being sent in the first place
-			iid = remove_functions(iid)
-			local msg_ser = minetest.serialize(iid)
-			if #msg_ser <= mesecon.setting("luacontroller_interruptid_maxlen", 256) then
-				mesecon.queue:add_action(pos, "lc_interrupt", {luac_id, iid}, time, iid, 1)
-			else
-				send_warning("An interrupt ID was too large!")
-			end
+-- The setting affects API so is not intended to be changeable at runtime
+local get_interrupt
+if mesecon.setting("luacontroller_lightweight_interrupts", false) then
+	-- use node timer
+	get_interrupt = function(pos, itbl, send_warning)
+		return (function(time, iid)
+			if type(time) ~= "number" then error("Delay must be a number") end
+			if iid ~= nil then send_warning("Interrupt IDs are disabled on this server") end
+			table.insert(itbl, function() minetest.get_node_timer(pos):start(time) end)
 		end)
 	end
-	return interrupt
+else
+	-- use global action queue
+	-- itbl: Flat table of functions to run after sandbox cleanup, used to prevent various security hazards
+	get_interrupt = function(pos, itbl, send_warning)
+		-- iid = interrupt id
+		local function interrupt(time, iid)
+			-- NOTE: This runs within string metatable sandbox, so don't *rely* on anything of the form (""):y
+			-- Hence the values get moved out. Should take less time than original, so totally compatible
+			if type(time) ~= "number" then error("Delay must be a number") end
+			table.insert(itbl, function ()
+				-- Outside string metatable sandbox, can safely run this now
+				local luac_id = minetest.get_meta(pos):get_int("luac_id")
+				-- Check if IID is dodgy, so you can't use interrupts to store an infinite amount of data.
+				-- Note that this is safe from alter-after-free because this code gets run after the sandbox has ended.
+				-- This runs outside of the timer and *shouldn't* harm perf. unless dodgy data is being sent in the first place
+				iid = remove_functions(iid)
+				local msg_ser = minetest.serialize(iid)
+				if #msg_ser <= mesecon.setting("luacontroller_interruptid_maxlen", 256) then
+					mesecon.queue:add_action(pos, "lc_interrupt", {luac_id, iid}, time, iid, 1)
+				else
+					send_warning("An interrupt ID was too large!")
+				end
+			end)
+		end
+		return interrupt
+	end
 end
 
-
 -- Given a message object passed to digiline_send, clean it up into a form
 -- which is safe to transmit over the network and compute its "cost" (a very
 -- rough estimate of its memory usage).
@@ -414,7 +427,6 @@ local function get_digiline_send(pos, itbl, send_warning)
 	end
 end
 
-
 local safe_globals = {
 	-- Don't add pcall/xpcall unless willing to deal with the consequences (unless very careful, incredibly likely to allow killing server indirectly)
 	"assert", "error", "ipairs", "next", "pairs", "select",
@@ -619,12 +631,13 @@ local function reset_formspec(meta, code, errmsg)
 	meta:mark_as_private("code")
 	code = minetest.formspec_escape(code or "")
 	errmsg = minetest.formspec_escape(tostring(errmsg or ""))
-	meta:set_string("formspec", "size[12,10]"..
-		"background[-0.2,-0.25;12.4,10.75;jeija_luac_background.png]"..
-		"textarea[0.2,0.2;12.2,9.5;code;;"..code.."]"..
-		"image_button[4.75,8.75;2.5,1;jeija_luac_runbutton.png;program;]"..
-		"image_button_exit[11.72,-0.25;0.425,0.4;jeija_close_window.png;exit;]"..
-		"label[0.1,9;"..errmsg.."]")
+	meta:set_string("formspec", "size[12,10]"
+		.."background[-0.2,-0.25;12.4,10.75;jeija_luac_background.png]"
+		.."label[0.1,8.3;"..errmsg.."]"
+		.."textarea[0.2,0.2;12.2,9.5;code;;"..code.."]"
+		.."image_button[4.75,8.75;2.5,1;jeija_luac_runbutton.png;program;]"
+		.."image_button_exit[11.72,-0.25;0.425,0.4;jeija_close_window.png;exit;]"
+		)
 end
 
 local function reset_meta(pos, code, errmsg)
@@ -650,6 +663,14 @@ local function reset(pos)
 	set_port_states(pos, {a=false, b=false, c=false, d=false})
 end
 
+local function node_timer(pos)
+	if minetest.registered_nodes[minetest.get_node(pos).name].is_burnt then
+		return false
+	end
+	run(pos, {type="interrupt"})
+	return false
+end
+
 -----------------------
 -- A.Queue callbacks --
 -----------------------
@@ -822,6 +843,7 @@ for d = 0, 1 do
 			mesecon.receptor_off(pos, output_rules)
 		end,
 		is_luacontroller = true,
+		on_timer = node_timer,
 		on_blast = mesecon.on_blastnode,
 	})
 end

mesecons_microcontroller/init.lua

@@ -571,6 +571,7 @@ yc.command_parsecondition = function(cond, L, eeprom)
 		if cond:sub(i+1, i+1) == nil then break end
 		if s == "&" then
 			if a==nil then return nil end
+			if b==nil then return nil end
 			local buf = ((a==1) and (b==1))
 			if buf == true  then buf = "1" end
 			if buf == false then buf = "0" end
@@ -580,6 +581,7 @@ yc.command_parsecondition = function(cond, L, eeprom)
 		end
 		if s == "|" then
 			if a==nil then return nil end
+			if b==nil then return nil end
 			local buf = ((a == 1) or (b == 1))
 			if buf == true  then buf = "1" end
 			if buf == false then buf = "0" end
@@ -589,6 +591,7 @@ yc.command_parsecondition = function(cond, L, eeprom)
 		end
 		if s == "~" then
 			if a==nil then return nil end
+			if b==nil then return nil end
 			local buf = (((a == 1) or (b == 1)) and not((a==1) and (b==1)))
 			if buf == true  then buf = "1" end
 			if buf == false then buf = "0" end

mesecons_movestones/doc/movestone/description.html

 Movestones are effectors that push the blocks in front of them. They move along on the right side of a mesecon wire track.
+A movestone trying to move into, or push other nodes into, an unloaded block doesn't move.

mesecons_movestones/doc/movestone_sticky/description.html

 Movestones are effectors that push the blocks in front of them. They move along on the right side of a mesecon wire track. Sticky ones also pull blocks.
+A sticky movestone trying to move into, or push other nodes into, an unloaded block doesn't move.
+A sticky movestone trying to pull nodes from an unloaded block moves but leaves them behind.

mesecons_mvps/init.lua

@@ -55,8 +55,6 @@ end
 
 -- tests if the node can be pushed into, e.g. air, water, grass
 local function node_replaceable(name)
-	if name == "ignore" then return true end
-
 	if minetest.registered_nodes[name] then
 		return minetest.registered_nodes[name].buildable_to or false
 	end
@@ -260,6 +258,10 @@ function mesecon.mvps_move_objects(pos, dir, nodestack, movefactor)
 	end
 end
 
+-- Never push into unloaded blocks. Don’t try to pull from them, either.
+-- TODO: load blocks instead, as with wires.
+mesecon.register_mvps_stopper("ignore")
+
 mesecon.register_mvps_stopper("doors:door_steel_b_1")
 mesecon.register_mvps_stopper("doors:door_steel_t_1")
 mesecon.register_mvps_stopper("doors:door_steel_b_2")

mesecons_pistons/doc/piston/description.html

 Pistons are effectors, they push up to 20 blocks in front of them. The push direction can be set by placing them from different angles.
+A piston pointing into an unloaded block won't extend.
+A piston retracting from an unloaded block works, but gravity-sensitive nodes above the empty space may not fall.

mesecons_pistons/doc/piston_sticky/description.html

 Sticky pistons are effectors, they push up to 20 blocks in front of them. The push direction can be set by placing them from different angles. Sticky ones also pull 1 block.
+A sticky piston pointing into an unloaded block won't extend.
+A sticky piston retracting from within an unloaded block works and pulls a node, but if it doesn't pull anything, then gravity-sensitive nodes above the empty space may not fall.
+An extended sticky piston that touches the surface of an unloaded block and loses signal retracts but doesn't pull anything.

mesecons_pistons/init.lua

@@ -55,7 +55,7 @@ local function piston_get_rules(node)
 	return rules
 end
 
-local function piston_remove_pusher(pos, node)
+local function piston_remove_pusher(pos, node, check_falling)
 	local pistonspec = get_pistonspec(node.name, "onname")
 	local dir = vector.multiply(minetest.facedir_to_dir(node.param2), -1)
 	local pusherpos = vector.add(pos, dir)
@@ -72,7 +72,14 @@ local function piston_remove_pusher(pos, node)
 		max_hear_distance = 20,
 		gain = 0.3,
 	})
-	minetest.check_for_falling(pusherpos)
+
+	if check_falling then
+		minetest.check_for_falling(pusherpos)
+	end
+end
+
+local function piston_after_dig(pos, node)
+	piston_remove_pusher(pos, node, true)
 end
 
 local piston_on = function(pos, node)
@@ -97,7 +104,7 @@ end
 local function piston_off(pos, node)
 	local pistonspec = get_pistonspec(node.name, "onname")
 	minetest.set_node(pos, {param2 = node.param2, name = pistonspec.offname})
-	piston_remove_pusher(pos, node)
+	piston_remove_pusher(pos, node, not pistonspec.sticky)
 
 	if not pistonspec.sticky then
 		return
@@ -293,7 +300,7 @@ minetest.register_node("mesecons_pistons:piston_normal_on", {
 	paramtype2 = "facedir",
 	is_ground_content = false,
 	drop = "mesecons_pistons:piston_normal_off",
-	after_dig_node = piston_remove_pusher,
+	after_dig_node = piston_after_dig,
 	node_box = piston_on_box,
 	selection_box = piston_on_box,
 	sounds = default.node_sound_wood_defaults(),
@@ -371,7 +378,7 @@ minetest.register_node("mesecons_pistons:piston_sticky_on", {
 	paramtype2 = "facedir",
 	is_ground_content = false,
 	drop = "mesecons_pistons:piston_sticky_off",
-	after_dig_node = piston_remove_pusher,
+	after_dig_node = piston_after_dig,
 	node_box = piston_on_box,
 	selection_box = piston_on_box,
 	sounds = default.node_sound_wood_defaults(),

mesecons_powerplant/doc/powerplant/description.html

-A power plant is a receptor that is always turned on: It provides energy.
+A power plant is a receptor that is always turned on: it provides energy.
+It continues to work in an unloaded block.

mesecons_pressureplates/doc/pressureplate_stone/description.html

-This receptor turns on if there's an object above it. And object can be a player, an item, a mob...
+This receptor turns on if there's an object above it. An object can be a player, an item, a mob...

mesecons_pressureplates/doc/pressureplate_wood/description.html

-This receptor turns on if there's an object above it. And object can be a player, an item, a mob...
+This receptor turns on if there's an object above it. An object can be a player, an item, a mob...

mesecons_random/doc/ghoststone/description.html

-Ghoststones disappear when powered, just like Removestones. But in contrast to Removestones, they Reappear again when not powered anymore and they are also conductive.
+Ghoststones disappear when powered, just like Removestones. But in contrast to Removestones, they reappear again when not powered anymore and they are also conductive.
+They work in inactive blocks.

mesecons_random/doc/removestone/description.html

-Removestones are propably the simplest effectors possible. They simply disappear when powered.
+Removestones are probably the simplest effectors possible. They simply disappear when powered.
+They work in inactive blocks.