The bug
Have a full block with a glass pane or iron fence on top of it, place a piston facing the glass pane/ iron fence with a 1 block space in between them, then stand in that 1 block space with the piston at face level and power it; Sometimes you will teleport on top of the solid block, but most of the time you should teleport on top of the glass pane / iron bars.
Linked issues
is duplicated by 5
MC-135319
Pistons push you up a block
Resolved
MC-152641
Players get teleported up a block when a piston pushes them into a solid block.
Resolved
MC-171483
Sideways piston can push player a block higher
Resolved
MC-172303
Pistons Pushing players up blocks
Resolved
MC-175630
Piston teleportation
Resolved
relates to 2
Attachments
Comments 21
It's possible it occurs more if you were moving shortly before pushing the button? Not certain about this though.
After testing further, you can reproduce the issue by (when facing the piston) walking backwards into the block under the iron bars. One thing to note though is the behavior seems to be different now than previously as the player gets put inside the iron bar rather than on top (as shown in MC-125926.mp4)
not teleporting it takes 1 gametick and is intended afaik