Case 1:
If I do surface.create_entity{name="fast-transport-belt", position=game.player.selected.position, fast_replace=true} then a yellow belt item-on-ground is created. This behavior is expected.
Case 2:
Same command, no yellow belt is created. Expected behavior: Yellow belt is created nearby.
This only seems to be a problem with belts. Other entities spill properly, even around and onto belts.
create_entity{fast_replace=true} can fail to drop belts
Re: create_entity{fast_replace=true} can fail to drop belts
Fixed for 0.15. You can work around the problem by adding the player=... option when using fast_replace to put the items into the player instead of dropping them.
If you want to get ahold of me I'm almost always on Discord.