`event.getPlayer().isJumping()` is false in `PlayerJumpEvent`

[HydrolienF]

Expected behavior

I expect player.isJumping() to return true at least when the player started jumping.
I assume it should also be concidered jumping while it does not have hit the ground again.

Observed/Actual behavior

player.isJumping() is false when in the air after pressing space and listening to EntityShootBowEvent.
player.isJumping() is false when pressing space and listening PlayerJumpEvent.

Steps/models to reproduce

1. Clone https://github.com/Mvndi/JumpTest
2. Run .\gradlew runServer
3. Join the local server.
4. Jump
5. Watch server console print something like this:

[12:58:47 INFO]: [JumpTest] EntityJumpEvent Jumping ?
[12:58:47 INFO]: [JumpTest] getEntity(): CraftPlayer{name=Hydrolien, uuid=18f22ccb-b2e3-46b6-8df9-b3843ef57c74}
[12:58:47 INFO]: [JumpTest] isJumping(): false
[12:58:47 INFO]: [JumpTest] getVelocity(): 0.0,-0.0784000015258789,0.0
[12:58:47 INFO]: [JumpTest] getVelocity().length(): 0.0784000015258789

Plugin and Datapack List

No datapack.
Only JumpTest plugin for print pupose only.

Paper version

This server is running Paper version 1.21.11-69-main@94d0c97 (2025-12-30T20:33:30Z) (Implementing API version 1.21.11-R0.1-SNAPSHOT)

Other

I tested the same test plugin in 1.21.10, 1.21.8, 1.21.4, 1.20.4 & 1.19.4 and always had isJumping(): false when jumping.
In 1.21.11, isJumping() is true for mobs when listening EntityJumpEvent.

[electronicboy]

Players don't set that flag, they just send relative movements

[HydrolienF]

Ok, thanks for the quick answer

[Warriorrrr]

Have you tried https://jd.papermc.io/paper/1.21.11/org/bukkit/Input.html#isJump() as an alternative?

[HydrolienF]

But it will stay in the Javadoc? https://jd.papermc.io/paper/1.21.11/org/bukkit/entity/LivingEntity.html#isJumping()

[electronicboy]

I mean, it refers to the entity flag state, a player jumping won't flip that flag state, the docs generally don't document entity specific behavioral caveats as that tends to be implementation detail, maybe somebody could add a note but the docs are accurate there

[HydrolienF]

Have you tried https://jd.papermc.io/paper/1.21.11/org/bukkit/Input.html#isJump() as an alternative?

Thanks for the idea. It's true for EntityJumpEvent and for EntityShootBowEvent if the player is still holding space. But not when the player stopped holding space. I will rely on velocity only.