in the newest snapshot (14w32d) the hitbox of the stairs is bugged.

(i don't know if this bug is reported yet, but after some research it seemed like it wasn't reported.)

the hitbox shows a different hitbox than it should be, in the first screenshot, i put glowstone on the sides where it doesn't show the hitbox.

the north-facing stairs show the hitbox of south-facing stairs.
the east-facing stairs show the hitbox of north-facing stairs
the south-facing stairs show the hitbox of east-facing stairs
the west-facing stairs show the hitbox of west-facing stairs (which is right )

p.s. it seems weird to me nobody has noticed this yet, so i doubt this isn't reported yet. if it is, just tell me.