Implement metadata-aware version of InvRef:remove_item()

doc/lua_api.md

@@ -7850,11 +7850,10 @@ An `InvRef` is a reference to an inventory.
   the stack of items can be fully taken from the list.
   If `match_meta` is false, only the items' names are compared
   (default: `false`).
-* `remove_item(listname, stack)`: take as many items as specified from the
-  list, returns the items that were actually removed (as an `ItemStack`)
-  -- note that any item metadata is ignored, so attempting to remove a specific
-  unique item this way will likely remove the wrong one -- to do that use
-  `set_stack` with an empty `ItemStack`.
+* `remove_item(listname, stack, [match_meta])`: take as many items as specified from the
+  list, returns the items that were actually removed (as an `ItemStack`).
+  If `match_meta` is `true`, the function also takes metadata into account
+  (since version `5.11.0`).
 * `get_location()`: returns a location compatible to
   `core.get_inventory(location)`.
     * returns `{type="undefined"}` in case location is not known

src/inventory.cpp

@@ -693,11 +693,11 @@ bool InventoryList::containsItem(const ItemStack &item, bool match_meta) const
 	return false;
 }
 
-ItemStack InventoryList::removeItem(const ItemStack &item)
+ItemStack InventoryList::removeItem(const ItemStack &item, bool match_meta)
 {
 	ItemStack removed;
 	for (auto i = m_items.rbegin(); i != m_items.rend(); ++i) {
-		if (i->name == item.name) {
+		if (i->name == item.name && (!match_meta || (i->metadata == item.metadata))) {
 			u32 still_to_remove = item.count - removed.count;
 			ItemStack leftover = removed.addItem(i->takeItem(still_to_remove),
 					m_itemdef);

src/inventory.h

@@ -262,7 +262,7 @@ class InventoryList
 	// If not as many items exist as requested, removes as
 	// many as possible.
 	// Returns the items that were actually removed.
-	ItemStack removeItem(const ItemStack &item);
+	ItemStack removeItem(const ItemStack &item, bool match_meta);
 
 	// Takes some items from a slot.
 	// If there are not enough, takes as many as it can.

src/script/lua_api/l_inventory.cpp

@@ -330,7 +330,7 @@ int InvRef::l_contains_item(lua_State *L)
 	return 1;
 }
 
-// remove_item(self, listname, itemstack or itemstring or table or nil) -> itemstack
+// remove_item(self, listname, itemstack or itemstring or table or nil, [match_meta]) -> itemstack
 // Returns the items that were actually removed
 int InvRef::l_remove_item(lua_State *L)
 {
@@ -339,8 +339,11 @@ int InvRef::l_remove_item(lua_State *L)
 	const char *listname = luaL_checkstring(L, 2);
 	ItemStack item = read_item(L, 3, getServer(L)->idef());
 	InventoryList *list = getlist(L, ref, listname);
+	bool match_meta = false;
+	if (lua_isboolean(L, 4))
+		match_meta = readParam<bool>(L, 4);
 	if(list){
-		ItemStack removed = list->removeItem(item);
+		ItemStack removed = list->removeItem(item, match_meta);
 		if(!removed.empty())
 			reportInventoryChange(L, ref);
 		LuaItemStack::create(L, removed);