I cannot tell whether that is a xNethack specific a or general effect
in various variants, or whether it is intentional (as designed)...

In the following setup (doorway, dug square with boulder, open door)

# --------
###.......|
0@.....|
###-......|
|.d__.0|
----.---

it is possible for me (@) and my pet (d) to enter the open door (-)
diagonally from the position where I stand.

Janis

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