Fix mobs operating when in, above or next to ignore

mods/CORE/mcl_util/init.lua

@@ -2,6 +2,13 @@ mcl_util = {}
 
 dofile(minetest.get_modpath(minetest.get_current_modname()).."/roman_numerals.lua")
 
+mcl_util.plane_adjacents = {
+	vector.new(1,0,0),
+	vector.new(-1,0,0),
+	vector.new(0,0,1),
+	vector.new(0,0,-1),
+}
+
 -- Updates all values in t using values from to*.
 function table.update(t, ...)
 	for _, to in ipairs {...} do

mods/ENTITIES/mcl_mobs/api.lua

@@ -387,6 +387,7 @@ local function on_step_work (self, dtime)
 	local pos = self.object:get_pos()
 	if not pos then return end
 
+	if self:check_in_unloaded_area(pos) then return end
 	if self:check_despawn(pos, dtime) then return true end
 	if self:outside_limits() then return end
 

mods/ENTITIES/mcl_mobs/physics.lua

@@ -679,11 +679,7 @@ function mob_class:do_env_damage()
 	local pos3 = vector.offset(pos, 0, 1, 0)
 	self.standing_under = node_ok(pos3, "air").name
 
-	-- don't fall when on ignore, just stand still
-	if self.standing_in == "ignore" then
-		self.object:set_velocity({x = 0, y = 0, z = 0})
-	-- wither rose effect
-	elseif self.standing_in == "mcl_flowers:wither_rose" then
+	if self.standing_in == "mcl_flowers:wither_rose" then
 		mcl_potions.give_effect_by_level("withering", self.object, 2, 2)
 	end
 
@@ -1094,3 +1090,32 @@ function mob_class:check_suspend(player_in_active_range)
 		return true
 	end
 end
+
+local plane_adjacents = table.copy(mcl_util.plane_adjacents)
+table.insert(plane_adjacents, vector.new(0,-1,0))
+
+local function is_node_loaded(pos)
+	local current_node = minetest.get_node(pos)
+	if current_node.name == "ignore" then
+		return false
+	end
+	return true
+end
+
+function mob_class:check_in_unloaded_area(pos)
+	local unloaded = false
+	if not is_node_loaded(pos) then
+		unloaded = true
+	else
+		for _,v in pairs(plane_adjacents) do
+			if not is_node_loaded(vector.add(pos, v)) then
+				unloaded = true
+			end
+		end
+	end
+	if unloaded then
+		-- do not fall or walk, or think. just stop it. we aren't ready for you yet
+		self.object:set_velocity(vector.zero())
+	end
+	return unloaded
+end