Affects Version/s: Minecraft 16w21b
Fix Version/s: Minecraft 1.10 Pre-Release 1
According to the changelog, /tp with relative coordinates now teleports relative to the executor, not the target. However, when command blocks teleport players, the command seems to teleport relative to the target.
1. create a superflat "redstone ready" world
2. Place down a repeating command block
3. set the command to
4. set the command block to "always active"
5. you will notice that, despite reporting the correct coordinates in the logs, the player will be teleported according to their current coordinates.