The bug
You cannot use fireworks to boost while you fly with an elytra if your entity id is 0, which is typically right after you started the game.
How to reproduce
Start the game
Open a world with no other entities
Start flying with an elytra and try to use fireworks to boost
→ The fireworks are used but fly straight in the air even if you are not right clicking a block
Code analysis
Based on 1.11.2 decompiled using MCP 9.35 rc1
The data parameter net.minecraft.entity.item.EntityFireworkRocket.field_191512_b
stores the entity id of the entity being boosted. The problem is that it treats 0 as not set, but stores the entity id without adding 1. Therefor a player with entity id 0 will not be boosted.
Related issues
is duplicated by
relates to
Comments


I have the same issue but only on old worlds. Maybe it is by design, because they removed the Mending/ Infinity combo?

This bug doesn't require old worlds for me.

Video: https://youtu.be/0Tpta3dRZv4
A reload of the world fix this.

Still in 1.11.2 🙂

Please do not mark unreleased versions as affected.
You don't have access to them yet.

I also experience this issue on MC:PC 1.11.2, in both creative and survival.

In my testing, this seems to be unrelated to teleporting or creative flying. Fireworks fail to work in the first world loaded after starting the game. If you close the world and open any other world, fireworks work correctly. You can trigger the bug again if you exit the game, restart the game, and load a single player world.

I've tested under Windows 10 and OS X Sierra. The bug happens for me under Windows 10, but not OS X.

I experienced this last night. Created a super flat world with the redstone conditions and the rockets had no affect on my flight. Flight works in my normal survival world that I purchase from a host and in a local single player game I've had since 1.8.

Confirmed for 17w06a

Confirmed for 1.12pre3

Confirmed for Minecraft 1.12

Can't confirm for 1.12.1-pre1?
Can confirm for MC 1.12.1.

Still in 1.12.2

Still in 17w45b.

Affects 18w01a.

Affects 18w10d

Affects 1.13

This bug does not only affect the first player that enters the game. After about two weeks of running a busy server, the entity IDs will overflow, which results in no player being able to use fireworks. Negative entity IDs are also ignored by this function (from 1.12.1 decompiled with MCP):
public boolean isAttachedToEntity() {
return ((Integer)this.dataManager.get(BOOSTED_ENTITY_ID)).intValue() > 0;
}
so annoying.. I really wanted to try the new feature but it wouldn't work..
Windows 10 Home
Intel Core i7