Paper: Sand disappearing after falling through end portal

[imnotdax]

What behaviour is expected:

___After placing 10 sand on top of an end portal, and it falling through and teleporting, it should place 1 block in the end and drop 9 blocks.___

What behaviour is observed:

___No block is placed, and only 8 blocks are dropped, effectively losing 2 blocks of sand.___

Steps/models to reproduce:

___Drop 10 sand above an end portal, and let it fall through.___

Plugin list:

___N/A___

Paper build number:

___280___

Anything else:

___When you place 2 sand, both sand disappear, but when you place >2 sand the amount of sand dropped in the end is amount of sand placed - 2.___

[i0xHeX]

Also can add few details:

• Reproduced this on b255 (and as author said in discord issue first detected in b213)
• Chunks in the end are not loaded by other players

[aikar]

It would of been 216 not 213 that likely caused it.

[imnotdax]

It would of been 216 not 213 that likely caused it.

I first found this on b213, and then tested on b280 which also had it.
This is the output of /version on a server with the same bug.

This server is running Paper version git-Paper-213 (MC: 1.15.2) (Implementing API version 1.15.2-R0.1-SNAPSHOT)

[aikar]

Well the likelihood of figuring that out just dropped 99% then....

Going to require someone else to find the cause then, as I honestly can't justify spending the time unless it's an easy one.
Too much else to work on

[MiniDigger]

basically, if somebody can try bisecting paper builds to find the exact one that caused this, it would be greatly appreachiated.

[Chew]

My adventures with trying to find this:
Every time, I put 11 blocks on top of an End Portal and break the bottom block. I also have no plugins loaded.
Paper-1.15.2 build 213 - Bug occurs
Paper-1.15.2 build 200 - Bug occurs
Paper-1.15.2build 150 - Bug occurs
Paper-1.15.2 build 100 - Bug occurs
Minecraft Vanilla 1.15.2 (Just to find intended behavior) - Obviously bug doesn't occur
Tested with Latest Spigot - Bug occurs!

It appears this is an underlying issue with Spigot itself.

[i0xHeX]

Found build where bug first appears:
https://papermc.io/ci/job/Paper-1.14/83/
(MC 1.14.2)

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[Chew]

Not sure if this is fixed yet. It still likely isn't, but if it is, we can close this.