The bug
When working with multiple singleplayer worlds (not tested on multiplayer), the player will spawn in at the wrong location, holding the item they had in their hand from the previous world, before being teleported to their correct spawn location and that item then disappears from their hand.
This issue has the occasional effect of playing the water enter/leaving sounds depending on the seed you're using and the environment. You can replicate the player position and item holding issue flawlessly, but the water sound effect one is a bit harder to repeat consistently.
How to reproduce
Make sure Minecraft is windowed (this will be easier to replicate.)
Create a new single-player creative world
Launch the world
Place any item from the creative menu in your hand
'Save and Quit to Title'
Create another new creative world
While it's generating, tab out to another window, or click on the desktop – anything to remove the window focus from Minecraft
After the world has generated, the "Game Menu" will appear. Notice you're holding the item from the previous world you were playing. Notice also your surroundings may be different from those you spawn into.
Click 'Back to Game'
Observe that the item you appear to have have teleported to your correct spawning location (if surroundings were different) and the item you were holding is now gone
Now we will repeat this on the other world, demonstrating the issue is consistent
Place a different item in your player's hand
'Save and Quit to Title'
Launch the first world you created
Tab out, or click the desktop, to remove the window focus from Minecraft
After the world has generated and the "Game Menu" appears, notice you're holding the item from the previous game and that your location surroundings will be different to the ones you're about to spawn back into
Notes
As I have explored this bug more and more, I've managed to replicate it consistently with the above steps. I have uploaded one final video demonstrating the entire bug, including items in hand. Please click the YouTube link for the best representation of this bug: https://www.youtube.com/watch?v=mRfegVLshnk
Linked issues
is duplicated by 1
relates to 1
Attachments
Comments 12
In my attempts to re-test this for 1.13-pre5, I managed to get it to do it repeatedly now with a "minecart rolls" sound (which was played back as audio and played back right at the end of the dirt loading screen, before the world appeared) on the same seed as above (-370992....)
Just for some better clarity around the splashing sound. I just tried one attempt and got two sounds played back. Exactly like this:
On the "Loading terrain" screen I got a "player submerged in water" sound effect
Once the game loaded and I was standing on grass I got a "player surfaces" type sound effect (Splashing.)
It was almost as if I became submerged momentarily before my player was positioned during the world load.
I've played with this some more and understand what is now happening with this bug. I have updated the description to more accurately reflect the issue and rewritten the steps. I have uploaded a new video showcasing the issue. Note during the world pre-load, I have tabbed out but due to the way I did the recording, that is not obvious. But the steps followed in the video are the same as those above, from step 4 onwards.
Updated accuracy of STR including some additional findings, and linked to a better representation of this bug via YouTube.
Relates to MC-133703.
Someone suggested it may be to do with whether the coordinates 0,0 are water or not. I have done some testing and found some another seed that seem to do this repeatedly, and they have a water block at 0,0. I'm not sure this is the cause yet, as there isn't a big enough sample size, and some worlds with water at 0,0 are not doing it in my tests.
668252533235536017
-3709921680383185983 (This is the seed from world zip linked in the original comments)