Update by @unknown:
Verification builds:
1.2.3.6, 1.2.5.15, 1.2.6.2 Retail
Summary:
When placing directional blocks (such as droppers, dispensers, pistons, observers and command blocks) on the ground around the player, and the player is elevated above the ground, the blocks should all be facing upwards. There is an inconsistency depending on the coordinates of the player. When the player moves into the negative axes, the directional block placement changes.
Steps to Reproduce:
In a flat world, place a bottom-half slab at position 4 5 4 and stand in the centre of it
Place 4 dispensers in each direction beside you (notice they all face upwards, as expected)
Now tp to -4 5 -4, place a slab, and stand in the centre
Again place 4 dispensers in each direction beside you
Observed Results:
When the player is positioned in negative x or z, the directional block placement is not consistent with that when the player is in positive x or z.
Expected Results:
When elevated, directional blocks should always be facing upwards, regardless of the player's coordinates.
Screenshots/Videos attached: Yes
Notes:
Original Description:
When i tried to place pistons facing upward below a block, they faces me mostly.
Tested for confirmation in Windows 10 1.2.9.1. The behavior changed. In either +X/+Z or -X/-Z quadrant, placing a dispenser next to the bottom slab you're standing on results in the dispenser facing upward, except when you are facing the +Z direction (South). In that case the dispenser is placed facing North.