The bug
If you use a flight duration firework rocket and land before the flight boost ends, if you activate your elytra again, the "boost" will still be active and you will fly as if you used a firework rocket when you have not. I've tried it with flight duration 3 rockets, unsure about the rest.
To reproduce
Equip elytra and fill your inventory with rockets
Switch into Survival mode
Deploy your elytra
Use a rocket to propell your flight
Immediately land on the ground
Deploy your elytra again
→ ❌ You are boosted without using rockets
Linked issues
Attachments
Comments 2
I was able to reproduce with default creative rockets, see the video I attached a few days ago.
Also, are you sure that this is working as intended? You would expect the momentum to be lost when you land. From a technical point of view, sure, that explanation makes sense, but from a game physics point of view, it does not. It seems very odd at least.
This issue is also reproducible in 1.14.4, but it's way harder to do so.
This is not reproducable with default creative rockets, they must be manually made (aim for flight duration 3 to make sure it's easy reproducable).
The momentum will be saved for the duration of the rockets, and will not carry over if the player waits longer than that to activate the elytra a second time.
WAI.