Splash potions are broken / All thrown potions are water potions

Relates to MC-85835.

Comment by @unknown on MC-92554:

Happens with all default and custom potions; the item data from the inventory potion is not stored on the ThrownPotion (defaulting to splash_potion with no effects, as well as a "ThrownPotion entity # has no item?!" error in log).

Yea, this is a game breaker.

I get the "ThrownPotion entity # has no item?!" spam as well, which it's filling up my server logs very fast.

Previously doable:

/summon ThrownPotion ~ ~ ~ {Motion:[0.0,0.5,0.0],Potion:{id:"minecraft:dirt",Count:1,tag:{Potion:"minecraft:swiftness"}}}

Now broken... 😞

The error is [Client thread/ERROR] : ThrownPotion entity 2415(and other numbers) has no item?!
and here is a video https://youtu.be/vPGCoNLTR7w

Well, apparently it says "Unable to summon object" if using this command:

/summon ThrownPotion ~ ~ ~ {Motion:[0.0,0.5,0.0],Potion:"minecraft:swiftness"}

@@unknown The format has changed: http://minecraft.gamepedia.com/Chunk_format#Projectiles

not only that, but that was never posible, your "previously doable" is the correct format

Hopefully this gets fixed - fast. Also got the NBTtag from the potion:

{Motion:[0:-0.17055549335343143d,1:-0.384266503147023d,2:0.24446597792495978d],shake:0b,xTile:-1,UUIDLeast:-8318137210266720776L,Potion:{id:"minecraft:splash_potion",Count:1b,Damage:0s},inGround:0b,Invulnerable:0b,Air:300s,OnGround:0b,Dimension:0,PortalCooldown:0,Rotation:[0:-34.901978f,1:-23.556435f],FallDistance:0.0f,inTile:"minecraft:air",UUIDMost:5961649110150892353L,ownerName:"RobuxShooters",Pos:[0:1353.4778149972935d,1:17.387680315199987d,2:1160.94360847279d],zTile:-1,Fire:0s,yTile:-1}

Seems that the tag for the Potion section is not there:

Potion:{id:"minecraft:splash_potion",Count:1b,Damage:0s}

@@unknown I think it doesn't have to be when there's a Damage (data) value present, but this value is 0, which means it's a water potion (it shouldn't be).

@Tan, @Steven, It's not the tag tag that's missing, it's everything. No matter what you provide it, it defaults to an ID of "minecraft:splash_potion", Count of 1, and Damage of 0. And no, the damage value no longer dictates what type of potion it is and is always 0 for potions.

I just wonder how they manage to break
potions like this, but out of all things,
potions get broken? First it was all tipped
arrows turning black in one of the older
snapshots since they were probably adding
new stuff at the time. But potions? makes
no sense.

@unknown: Always remember that you're testing snapshots. That's not a full featured bug free version, it's simply the compiled state of the head of the development branch - hence the name. In a snapshot everything can (and will) happen.

Confirmed. It's pretty funny fighting witches - they can't hurt you at all.

Skylinerw, what do you mean by everything is missing?

Confirmed.

@Tan, An exmaple of the inventory item's NBT data for a lingering potion, modified to include a stack size of 2 to show that it's disregarded:

{id:"minecraft:lingering_potion",Count:2,Damage:0,tag:{Potion:"minecraft:swiftness"}}

The ThrownPotion entity will not take any of that data whatsoever, not just from what's within the "tag" tag. And because the ThrownPotion entity is now missing the potion data, it attempts to recover by adding default data, which is:

{id:"minecraft:splash_potion",Count:1,Damage:0}

I can confirm that splash potions of healing, harming, and regeneration are working in 15w47b. I didn't try any others.