When trying to use wooden forms for their "items fall through the
bottom" feature, e.g. for stack hoppers or "laundry chutes",
accidentally putting something like planks or glass into it will
permanently transform it into a storage container that no longer
has the desired property. Also, forms used in machines will
transform into frames if hit by a door when there's nothing
inside.
Allow players to put a stick inside to "brace" the form to stay
as a form permanently, disabling its use for any other purpose and
preventing other accidental transformations.
cfbea05d14
