Rewrite protection testing

Now it checks for pushing into protected area as well

mesecons_mvps/init.lua

@@ -145,29 +145,36 @@ function mesecon.mvps_mark_owner(pos, placer)
 	end
 end
 
-local function prot_deny() return true end
-local function prot_allow() return false end
+local function add_pos(positions, pos)
+	local hash = minetest.hash_node_position(pos)
+	positions[hash] = pos
+end
 
-local function make_is_protected(player_name)
+local function are_protected(positions, player_name)
 	local mode = mesecon.setting("mvps_protection_mode", "normal")
 	if mode == "ignore" then
-		return prot_allow
+		return false
 	end
+	local name = player_name
 	if player_name == "" or not player_name then -- legacy MVPS
 		if mode == "normal" then
-			player_name = "$unknown" -- sentinel, for checking for *any* protection
+			name = "$unknown" -- sentinel, for checking for *any* protection
 		elseif mode == "compat" then
-			return prot_allow
+			return false
 		elseif mode == "restrict" then
-			return prot_deny
+			return true
 		else
 			error("Invalid protection mode")
 		end
 	end
 	local is_protected = minetest.is_protected
-	return function(pos)
-		return is_protected(pos, player_name)
+	for _, pos in pairs(positions) do
+		if is_protected(pos, name) then
+			minetest.record_protection_violation(pos, player_name)
+			return true
+		end
 	end
+	return false
 end
 
 function mesecon.mvps_push(pos, dir, maximum, player_name)
@@ -194,16 +201,21 @@ function mesecon.mvps_push_or_pull(pos, stackdir, movedir, maximum, all_pull_sti
 	local nodes = mesecon.mvps_get_stack(pos, movedir, maximum, all_pull_sticky)
 
 	if not nodes then return end
+
+	local protection_check_set = {}
+	if vector.equals(stackdir, movedir) then -- pushing
+		add_pos(protection_check_set, pos)
+	end
 	-- determine if one of the nodes blocks the push / pull
-	local is_protected = make_is_protected(player_name)
 	for id, n in ipairs(nodes) do
 		if mesecon.is_mvps_stopper(n.node, movedir, nodes, id) then
 			return
 		end
-		if is_protected(n.pos) then
-			minetest.record_protection_violation(n.pos, player_name)
-			return
-		end
+		add_pos(protection_check_set, n.pos)
+		add_pos(protection_check_set, vector.add(n.pos, movedir))
+	end
+	if are_protected(protection_check_set, player_name) then
+		return
 	end
 
 	-- remove all nodes