Paper: [1.16.2] items are disappearing when picked up

[rrvk]

What behaviour is expected:

To pick up 1 item of a stack of what is on the ground

What behaviour is observed:

I pick up a whole stack but only 1 is added into my inventory because there is no more space and the other 63 are gone

Steps/models to reproduce:

• fill your inventory with something, so all the spaces are filled (for example coal)
• then drop a couple of stacks of an other item on the ground (for example coal ore)
• make 1 space in your inventory (hotbar) so you can pick up items, you will pick up 1 whole stack
• then drop/place 1 item of the stack
• you will pick up a whole stack but only 1 item get added to your invetory because there is no more space then that and the other 63 items are lost

Plugin list:

None

Paper version:

This server is running Paper version git-Paper-149 (MC: 1.16.2) (Implementing API version 1.16.2-R0.1-SNAPSHOT)

Anything else:

I have recreated this on a clean paper instal with no property changes

[calumari]

Confirmed in 150.

Iirc, this is the intended behaviour when picking up items in creative. However, it also happens in survival, which it shouldn't.

Video: https://streamable.com/r4rxce

Edit: It also happens upstream (git-Spigot-b5a13e6-bf45161) but not in vanilla.
Edit 2: Reported upstream.

[rrvk]

This now has been fixed upstream thanks for the report upstream @calumari
and upstream with this fix has been merge into paper https://github.com/PaperMC/Paper/commit/757948dca3823a3a6f9fad0049459675b7cc073f

I have tested this issue again on paper 152 and the issue is no longer there thanks!