Add MVPS protection support

mesecons_mvps/init.lua

@@ -133,31 +133,65 @@ function mesecon.mvps_get_stack(pos, dir, maximum, all_pull_sticky)
 	return nodes
 end
 
-function mesecon.mvps_push(pos, dir, maximum)
-	return mesecon.mvps_push_or_pull(pos, dir, dir, maximum)
+local function prot_deny() return true end
+local function prot_allow() return false end
+
+local function make_is_protected(player_name)
+	local mode = mesecon.setting("mvps_protection_mode", "normal")
+	if mode == "ignore" then
+		return prot_allow
+	end
+	if player_name == "" or not player_name then -- legacy MVPS
+		if mode == "normal" then
+			player_name = "$unknown" -- sentinel, for checking for *any* protection
+		elseif mode == "compat" then
+			return prot_allow
+		elseif mode == "restrict" then
+			return prot_deny
+		else
+			error("Invalid protection mode")
+		end
+	end
+	local is_protected = minetest.is_protected
+	return function(pos)
+		return is_protected(pos, player_name)
+	end
 end
 
-function mesecon.mvps_pull_all(pos, dir, maximum)
-	return mesecon.mvps_push_or_pull(pos, vector.multiply(dir, -1), dir, maximum, true)
+function mesecon.mvps_push(pos, dir, maximum, player_name)
+	return mesecon.mvps_push_or_pull(pos, dir, dir, maximum, false, player_name)
 end
 
-function mesecon.mvps_pull_single(pos, dir, maximum)
-	return mesecon.mvps_push_or_pull(pos, vector.multiply(dir, -1), dir, maximum)
+function mesecon.mvps_pull_all(pos, dir, maximum, player_name)
+	return mesecon.mvps_push_or_pull(pos, vector.multiply(dir, -1), dir, maximum, true, player_name)
 end
 
--- pos: pos of mvps; stackdir: direction of building the stack
+function mesecon.mvps_pull_single(pos, dir, maximum, player_name)
+	return mesecon.mvps_push_or_pull(pos, vector.multiply(dir, -1), dir, maximum, false, player_name)
+end
+
+-- pos: pos of mvps
+-- stackdir: direction of building the stack
 -- movedir: direction of actual movement
 -- maximum: maximum nodes to be pushed
 -- all_pull_sticky: All nodes are sticky in the direction that they are pulled from
-function mesecon.mvps_push_or_pull(pos, stackdir, movedir, maximum, all_pull_sticky)
+-- player_name: Player responsible for the action.
+--  - empty string means legacy MVPS, actual check depends on configuration
+--  - "$unknown" is a sentinel for forcing the check
+function mesecon.mvps_push_or_pull(pos, stackdir, movedir, maximum, all_pull_sticky, player_name)
 	local nodes = mesecon.mvps_get_stack(pos, movedir, maximum, all_pull_sticky)
 
 	if not nodes then return 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
 	end
 
 	-- remove all nodes

settingtypes.txt

@@ -28,6 +28,17 @@ mesecon.luacontroller_memsize (Controller memory limit) int 100000 10000 1000000
 # IID is ignored and at most one interrupt may be queued if this setting is enabled.
 mesecon.luacontroller_lightweight_interrupts (Lightweight interrupts) bool false
 
+[mesecons_mvps]
+
+# In pre-existing world, MVPS may not be labelled with the owner.
+# Protection handling for them is configurable.
+# - normal: allow legacy MVPS to work in unprotected areas only
+# - compat: allow legacy MVPS to work everywhere
+# - ignore: allow all MVPS to work everywhere
+# - restrict: disallow legacy MVPS
+# Note that new unowned (e.g. machine-placed) MVPS are always
+# handled as in `normal` mode.
+mesecon.mvps_protection_mode (MVPS [movestones, pistons] protection handling) enum normal normal,compat,ignore,restrict
 
 [mesecons_movestones]