Stepping down while sneaking allows falling off of blocks

While sneaking, if one steps down a half-block, they can fall off of the blocks being snuck on. For instance, descending stairway while sneaking while walking at a diagonal will result in falling off of the stairs, instead of remaining on them as would happen on a flat path.

This happens with any block that can be stepped down from while sneaking, including stairs, slabs, redstone repeaters, trapdoors, and snow. Repeaters in particular are annoying for redstone lines built without any kind of walls next to them.

Oddly, carpet is not affected, despite it having a slightly raised hitbox.