"--rev x" also matches against the short node number

[Dennis Brakhane]

Why are you using revision numbers in the first place? You know that they are
specific to a local repository and you will get differences once you merge with
another remote repository. Once you do that, your and the remote repository will
not agree on what revision 42 is.

You should really use the changeset identifiers, otherwise you probably will run
into some trouble later.