Add persistent player-specific metadata into mcl_playerinfo, simple cart reattachment (only exists if the luaentity for the cart exists when the player logs in)

mods/ENTITIES/mcl_minecarts/carts.lua

@@ -42,6 +42,8 @@ local function detach_driver(self)
 	-- Update cart informatino
 	self._driver = nil
 	self._start_pos = nil
+	local meta = mcl_playerinfo.get_mod_meta(driver_name, modname)
+	meta.attached_to = nil
 
 	-- Detatch the player object from the minecart
 	local player = minetest.get_player_by_name(driver_name)
@@ -609,3 +611,42 @@ minetest.register_globalstep(function(dtime)
 	end
 end)
 
+minetest.register_on_joinplayer(function(player)
+	local player_name = player:get_player_name()
+	local meta = mcl_playerinfo.get_mod_meta(player_name, modname)
+	local cart_uuid = meta.attached_to
+	if cart_uuid then
+		print("Trying to reattach "..player_name.." to cart #"..cart_uuid)
+		local cartdata = get_cart_data(cart_uuid)
+
+		-- Can't get into a cart that was destroyed
+		if not cartdata then
+			print("Failed to get cartdata")
+			return
+		end
+
+		-- Don't reattach players if someone else got in the cart
+		if cartdata.last_player ~= player_name then
+			print("Somebody else got in the cart while you were gone")
+			return
+		end
+
+		minetest.after(0.2,function(player_name, cart_uuid)
+			local player = minetest.get_player_by_name(player_name)
+			if not player then
+				print("Can't get an ObjectRef for "..player_name)
+				return
+			end
+
+			local cart = mcl_util.get_luaentity_from_uuid(cart_uuid)
+			if not cart then
+				print("Can't find the luaentity for cart #"..cart_uuid)
+				return
+			end
+
+			mod.attach_driver(cart, player)
+
+		end, player_name, cart_uuid)
+	end
+end)
+

mods/ENTITIES/mcl_minecarts/carts/minecart.lua

@@ -16,6 +16,41 @@ local function activate_normal_minecart(self)
 	end
 end
 
+function mod.attach_driver(cart, player)
+	local staticdata = cart._staticdata
+
+	-- Make sure we have a player
+	if not player or not player:is_player() then return end
+
+	local player_name = player:get_player_name()
+	if cart._driver or player:get_player_control().sneak then return end
+
+	-- Update cart information
+	cart._driver = player_name
+	cart._start_pos = cart.object:get_pos()
+
+	-- Keep track of player attachment
+	local meta = mcl_playerinfo.get_mod_meta(player_name, modname)
+	meta.attached_to = cart._uuid
+	staticdata.last_player = player_name
+
+	-- Update player information
+	local uuid = staticdata.uuid
+	mcl_player.player_attached[player_name] = true
+	minetest.log("action", player_name.." entered minecart #"..tostring(uuid).." at "..tostring(cart._start_pos))
+
+	-- Attach the player object to the minecart
+	player:set_attach(cart.object, "", vector.new(1,-1.75,-2), vector.new(0,0,0))
+	minetest.after(0.2, function(name)
+		local player = minetest.get_player_by_name(name)
+		if player then
+			mcl_player.player_set_animation(player, "sit" , 30)
+			player:set_eye_offset(vector.new(0,-5.5,0), vector.new(0,-4,0))
+			mcl_title.set(player, "actionbar", {text=S("Sneak to dismount"), color="white", stay=60})
+		end
+	end, player_name)
+end
+
 mod.register_minecart({
 	itemstring = "mcl_minecarts:minecart",
 	craft = {
@@ -39,37 +74,7 @@ mod.register_minecart({
 	},
 	icon = "mcl_minecarts_minecart_normal.png",
 	drop = {"mcl_minecarts:minecart"},
-	on_rightclick = function(self, clicker)
+	on_rightclick = mod.attach_driver,
-		-- Make sure we have a player
-		if not clicker or not clicker:is_player() then return end
-
-		local player_name = clicker:get_player_name()
-		if self._driver or clicker:get_player_control().sneak then return end
-
-		-- Update cart information
-		self._driver = player_name
-		self._start_pos = self.object:get_pos()
-
-		-- Update player information
-		local uuid = self._staticdata.uuid
-		local playerinfo = mcl_playerinfo[player_name]
-		if playerinfo and self._staticdata then
-			playerinfo.attached_to = uuid
-		end
-		mcl_player.player_attached[player_name] = true
-		minetest.log("action", player_name.." entered minecart #"..tostring(uuid).." at "..tostring(self._start_pos))
-
-		-- Attach the player object to the minecart
-		clicker:set_attach(self.object, "", vector.new(1,-1.75,-2), vector.new(0,0,0))
-		minetest.after(0.2, function(name)
-			local player = minetest.get_player_by_name(name)
-			if player then
-				mcl_player.player_set_animation(player, "sit" , 30)
-				player:set_eye_offset(vector.new(0,-5.5,0), vector.new(0,-4,0))
-				mcl_title.set(clicker, "actionbar", {text=S("Sneak to dismount"), color="white", stay=60})
-			end
-		end, player_name)
-	end,
 	on_activate_by_rail = activate_normal_minecart,
 	_mcl_minecarts_on_step = function(self, dtime)
 		-- Grab mob

mods/PLAYER/mcl_playerinfo/init.lua

@@ -1,7 +1,10 @@
 local table = table
 
+local storage = minetest.get_mod_storage()
+
 -- Player state for public API
 mcl_playerinfo = {}
+local player_mod_metadata = {}
 
 -- Get node but use fallback for nil or unknown
 local function node_ok(pos, fallback)
@@ -73,6 +76,23 @@ minetest.register_globalstep(function(dtime)
 
 end)
 
+function mcl_playerinfo.get_mod_meta(player_name, modname)
+	-- Load the player's metadata
+	local meta = player_mod_metadata[player_name]
+	if not meta then
+		meta = minetest.deserialize(storage:get_string(player_name))
+	end
+	if not meta then
+		meta = {}
+	end
+	player_mod_metadata[player_name] = meta
+
+	-- Get the requested module's section of the metadata
+	local mod_meta = meta[modname] or {}
+	meta[modname] = mod_meta
+	return mod_meta
+end
+
 -- set to blank on join (for 3rd party mods)
 minetest.register_on_joinplayer(function(player)
 	local name = player:get_player_name()
@@ -84,7 +104,6 @@ minetest.register_on_joinplayer(function(player)
 		node_stand_below = "",
 		node_head_top = "",
 	}
-
 end)
 
 -- clear when player leaves
@@ -93,3 +112,9 @@ minetest.register_on_leaveplayer(function(player)
 
 	mcl_playerinfo[name] = nil
 end)
+
+minetest.register_on_shutdown(function()
+	for name,data in pairs(player_mod_metadata) do
+		storage:set_string(name, minetest.serialize(data))
+	end
+end)