Various map item fixes

- Fix appearance in hand/in item form
- Allow placed maps to be dug by punching them
- Properly save metadata when creating a new map for the first time

items.lua

@@ -102,6 +102,7 @@ end);
 minetest.register_node("cartographer:map", {
     description = "Map",
     inventory_image = "cartographer_map.png",
+    wield_image = "cartographer_map.png",
     tiles = { "cartographer_map.png" },
     drawtype = "signlike",
     paramtype = "light",
@@ -116,6 +117,11 @@ minetest.register_node("cartographer:map", {
         },
     },
 
+    groups = {
+        attached_node = 1,
+        dig_immediate = 3,
+    },
+
     -- Called when this node is placed in the world. Copies map data from the
     -- item to the node.
     -- pos: The position of the node
@@ -131,6 +137,18 @@ minetest.register_node("cartographer:map", {
         return false;
     end,
 
+    -- Called when this node is dug. Turns the node into an item.
+    -- pos: The position of the node
+    on_dig = function(pos, _, _)
+        local node_meta = minetest.get_meta(pos):to_table();
+        local item = ItemStack("cartographer:map");
+        item:get_meta():from_table(node_meta);
+
+        if minetest.add_item(pos, item) then
+            minetest.remove_node(pos);
+        end
+    end,
+
     -- Called when a player right-clicks this node. Display's the map's
     -- content, creating it if it doesn't exist.
     -- pos: The position of the node
@@ -147,6 +165,20 @@ minetest.register_node("cartographer:map", {
     on_use = function(stack, player)
         cartographer.map_sound("cartographer_open_map", player);
         show_map_meta(stack:get_meta(), player);
+        return stack;
+    end,
+
+    -- Called when a node is about to be turned into an item. Copies all
+    -- metadata into any items matching this node's name.
+    -- oldnode: The old node's data
+    -- oldmeta: A table containing the old node's metadata
+    -- drops: A table containing the new items
+    preserve_metadata = function(_, oldnode, oldmeta, drops)
+        for _,item in ipairs(drops) do
+            if item:get_name() == oldnode.name then
+                item:get_meta():from_table({fields=oldmeta});
+            end
+        end
     end,
 });