[2.1.13] Underground belts on top of normal belt no longer auto rotate

[Mnemonic]

08-05-2026, 07-40-21.png (453.11 KiB) Viewed 330 times

When placing an underground on top of a normal belt, the underground doesn't rotate and become an upderground. It works fine if not on top of an existing belt.

[riking]

The change log lists a change here, but that change was only supposed to apply to fast replace on an existing underground with an exit already placed. It appears that the no rotation was instead applied to all fast replace.

EDIT: In particular, fast replace on an underground that exist but does not have a matching pair should also not suppress rotation.

[koelkastdeur16]

Same issue when placing on an existing ghost belt

[boskid]

So far this report looks like full of observations that behavior was changed but no arguments saying why the changed behavior is incorrect which leaves me no choice to throw this to Not a bug.

[Bilka]

It breaks the third gif in https://www.factorio.com/blog/post/fff-206, this is clearly a bug.

[Trainzack]

The same behavior is also occurring when replacing pipes with pipe to ground.

[Bilka]

Indeed, and that is shown off in https://factorio.com/blog/post/fff-240 so also a bug that it is now broken.