The bug
Flying really close to the ground, but still over. (i.e 0,00001 blocks over the ground) you will emit walking particles whilst holding the sprint key.
How to reproduce
Stand still in the air (levitating)
/tp
yourself 0.000001 over a block, i.e/tp ~ 75.00001 ~
Start sprint-flying
Code analysis
Code analysis by @unknown can be found in this comment.
Linked issues
is duplicated by 1
Comments 11
Is this still an issue in the latest snapshot 16w44a? If so please update the affected versions.
This is an automated comment on any open or reopened issue with out-of-date affected versions.

Confirmed for 1.12-pre7
Can confirm for MC 1.12.1.
Related to MC-46417
The following is based on a decompiled version of Minecraft 1.12 using MCP 9.40pre-1.
This happens because the class net.minecraft.entity.player.EntityPlayer
doesn't override the method net.minecraft.entity.Entity.spawnRunningParticles()
, which means the game doesn't check if the player is on the ground (it only checks if the player is sprinting and if the player isn't in water) before it spawns running particles.
Suggested fix: net.minecraft.entity.player.EntityPlayer
@Override
public void spawnRunningParticles() {
if(this.onGround) {
super.spawnRunningParticles();
}
}
This is basically just an improved version of the fix posted here as it fixes both MC-46417 and MC-94535 because the field net.minecraft.entity.Entity.onGround
will always be false
if the player is in spectator mode.

Affects 18w20c
Confirmed for 1.13-pre8
Confirmed for 1.13
Confirmed for 18w30b
Can confirm for 1.14.3
Confirmed for 15w51b, though I remember noticing it in previous versions as well. Also happens in spectator mode while inside blocks. Sprint particles generate as long as you're 0.2 blocks and lower from the surface of the ground.