Move bag storage to player attributes

Compatible with 0.4.16 or later
Fixes an item duplication bug for the four player inventory slots on each join
Clean up old player lists after saving

1 files changed, 99 insertions, 42 deletions

diff --git a/bags.lua b/bags.lua
index 6d0842f..e93a317 100644
--- a/bags.lua
+++ b/bags.lua
@@ -31,11 +31,18 @@ unified_inventory.register_button("bags", {
 	hide_lite=true
 })
 
+local function get_player_bag_stack(player, i)
+	return minetest.get_inventory({
+		type = "detached",
+		name = player:get_player_name() .. "_bags"
+	}):get_stack("bag" .. i, 1)
+end
+
 for i = 1, 4 do
 	local bi = i
 	unified_inventory.register_page("bag"..bi, {
 		get_formspec = function(player)
-			local stack = player:get_inventory():get_stack("bag"..bi, 1)
+			local stack = get_player_bag_stack(player, bi)
 			local image = stack:get_definition().inventory_image
 			local formspec = ("image[7,0;1,1;"..image.."]"
 					.."label[0,0;"..F("Bag @1", bi).."]"
@@ -58,7 +65,7 @@ for i = 1, 4 do
 			end
 			local inv = player:get_inventory()
 			for i = 1, 4 do
-				local def = inv:get_stack("bag"..i, 1):get_definition()
+				local def = get_player_bag_stack(player, i):get_definition()
 				local button
 				if def.groups.bagslots then
 					local list_name = "bag"..i.."contents"
@@ -89,7 +96,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 	end
 	for i = 1, 4 do
 		if fields["bag"..i] then
-			local stack = player:get_inventory():get_stack("bag"..i, 1)
+			local stack = get_player_bag_stack(player, i)
 			if not stack:get_definition().groups.bagslots then
 				return
 			end
@@ -99,67 +106,117 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 	end
 end)
 
+local function save_bags_metadata(player, bags_inv)
+	local is_empty = true
+	local bags = {}
+	for i = 1, 4 do
+		local bag = "bag"..i
+		if not bags_inv:is_empty(bag) then
+			-- Stack limit is 1, otherwise use stack:to_string()
+			bags[i] = bags_inv:get_stack(bag, 1):get_name()
+			is_empty = false
+		end
+	end
+	if is_empty then
+		player:set_attribute("unified_inventory:bags", nil)
+	else
+		player:set_attribute("unified_inventory:bags",
+			minetest.serialize(bags))
+	end
+end
+
+local function load_bags_metadata(player, bags_inv)
+	local player_inv = player:get_inventory()
+	local bags_meta = player:get_attribute("unified_inventory:bags")
+	local bags = bags_meta and minetest.deserialize(bags_meta) or {}
+	local dirty_meta = false
+	if not bags_meta then
+		-- Backwards compatiblity
+		for i = 1, 4 do
+			local bag = "bag"..i
+			if not player_inv:is_empty(bag) then
+				-- Stack limit is 1, otherwise use stack:to_string()
+				bags[i] = player_inv:get_stack(bag, 1):get_name()
+				dirty_meta = true
+			end
+		end
+	end
+	-- Fill detached slots
+	for i = 1, 4 do
+		local bag = "bag"..i
+		bags_inv:set_size(bag, 1)
+		bags_inv:set_stack(bag, 1, bags[i] or "")
+	end
+
+	if dirty_meta then
+		-- Requires detached inventory to be set up
+		save_bags_metadata(player, bags_inv)
+	end
+
+	-- Clean up deprecated garbage after saving
+	for i = 1, 4 do
+		local bag = "bag"..i
+		player_inv:set_size(bag, 0)
+	end
+end
+
 minetest.register_on_joinplayer(function(player)
 	local player_inv = player:get_inventory()
 	local player_name = player:get_player_name()
 	local bags_inv = minetest.create_detached_inventory(player_name.."_bags",{
 		on_put = function(inv, listname, index, stack, player)
-			player:get_inventory():set_stack(listname, index, stack)
 			player:get_inventory():set_size(listname.."contents",
 					stack:get_definition().groups.bagslots)
-		end,
-		on_take = function(inv, listname, index, stack, player)
-			player:get_inventory():set_stack(listname, index, nil)
+			save_bags_metadata(player, inv)
 		end,
 		allow_put = function(inv, listname, index, stack, player)
 			local new_slots = stack:get_definition().groups.bagslots
-			if new_slots then
-				local player_inv = player:get_inventory()
-				local old_slots = player_inv:get_size(listname.."contents")
+			if not new_slots then
+				return 0
+			end
+			local player_inv = player:get_inventory()
+			local old_slots = player_inv:get_size(listname.."contents")
 
-				if new_slots >= old_slots then
-					return 1
-				else
-					-- using a smaller bag, make sure it fits
-					local old_list = player_inv:get_list(listname.."contents")
-					local new_list = {}
-					local slots_used = 0
-					local use_new_list = false
-
-					for i, v in ipairs(old_list) do
-						if v and not v:is_empty() then
-							slots_used = slots_used + 1
-							use_new_list = i > new_slots
-							new_list[slots_used] = v
-						end
-					end
-					if new_slots >= slots_used then
-						if use_new_list then
-							player_inv:set_list(listname.."contents", new_list)
-						end
-						return 1
-					end
+			if new_slots >= old_slots then
+				return 1
+			end
+
+			-- using a smaller bag, make sure it fits
+			local old_list = player_inv:get_list(listname.."contents")
+			local new_list = {}
+			local slots_used = 0
+			local use_new_list = false
+
+			for i, v in ipairs(old_list) do
+				if v and not v:is_empty() then
+					slots_used = slots_used + 1
+					use_new_list = i > new_slots
+					new_list[slots_used] = v
 				end
 			end
-			return 0
+			if new_slots >= slots_used then
+				if use_new_list then
+					player_inv:set_list(listname.."contents", new_list)
+				end
+				return 1
+			end
 		end,
 		allow_take = function(inv, listname, index, stack, player)
 			if player:get_inventory():is_empty(listname.."contents") then
 				return stack:get_count()
-			else
-				return 0
 			end
+			return 0
 		end,
-		allow_move = function(inv, from_list, from_index, to_list, to_index, count, player)
+		on_take = function(inv, listname, index, stack, player)
+			player:get_inventory():set_size(listname.."contents", 0)
+			save_bags_metadata(player, inv)
+		end,
+		allow_move = function()
 			return 0
 		end,
 	}, player_name)
-	for i=1,4 do
-		local bag = "bag"..i
-		player_inv:set_size(bag, 1)
-		bags_inv:set_size(bag, 1)
-		bags_inv:set_stack(bag, 1, player_inv:get_stack(bag, 1))
-	end
+
+	load_bags_metadata(player, bags_inv)
 end)
 
 -- register bag tools