Furnace: Cooking craft recipe output replacements not working

[JurajVajda]

If a crafting recipe output has a replacement item it will try to put that replacement item in furnace src slot, since there can be multiple items (with replacements) in src inventory (of furnace) it will not add the replacement item to the src slot - unless it's the last item and src slot is empty. I would expect this to work similar to the fuel slot where the replacement item will be added to fuel slot if empty, to dest slots if fuel not empty or drop on top of the furnace if all slots are full.

Reference line:

minetest_game/mods/default/furnace.lua

Line 154 in 0a90bd8

inv:set_stack("src", 1, aftercooked.items[1])

Minetest: 5.4.0
Game: minetest_game
OS: Mac OS 11.2.3

Can be reproduced by adding multiple items with replacements in recipe to the src of furnace.

• Expected: all replacement items are returned.
• Actual: only last replacement item is returned.

[p-ouellette]

While the engine does support it, replacements support for cooking recipes is not documented in lua_api.txt and I can't think of any case where it would make sense.