Add compatibility to protector mods

steel/depends.txt

@@ -1,3 +1,5 @@
 default
 streets?
 homedecor?
+protector?
+node_ownership?

steel/init.lua

@@ -6,11 +6,46 @@ else
 	steel_expect_infinite_stacks = false
 end
 
+function steel_node_is_owned(pos, placer)
+	local ownername = false
+	if type(IsPlayerNodeOwner) == "function" then					-- node_ownership mod
+		if HasOwner(pos, placer) then						-- returns true if the node is owned
+			if not IsPlayerNodeOwner(pos, placer:get_player_name()) then
+				if type(getLastOwner) == "function" then		-- ...is an old version
+					ownername = getLastOwner(pos)
+				elseif type(GetNodeOwnerName) == "function" then	-- ...is a recent version
+					ownername = GetNodeOwnerName(pos)
+				else
+					ownername = "someone"
+				end
+			end
+		end
+
+	elseif type(isprotect)=="function" then 					-- glomie's protection mod
+		if not isprotect(5, pos, placer) then
+			ownername = "someone"
+		end
+	elseif type(protector)=="table" and type(protector.can_dig)=="function" then 					-- Zeg9's protection mod
+		if not protector.can_dig(5, pos, placer) then
+			ownername = "someone"
+		end
+	end
+
+	if ownername ~= false then
+		minetest.chat_send_player( placer:get_player_name(), ("Sorry, %s owns that spot."):format(ownername) )
+		return true
+	else
+		return false
+	end
+end
+
 function steel_rotate_and_place(itemstack, placer, pointed_thing)
 
 	local node = minetest.env:get_node(pointed_thing.under)
 	if not minetest.registered_nodes[node.name] or not minetest.registered_nodes[node.name].on_rightclick then
-
+		if steel_node_is_owned(pointed_thing.above, placer) then
+			return itemstack
+		end
 		local above = pointed_thing.above
 		local under = pointed_thing.under
 		local pitch = placer:get_look_pitch()