tests/unwrap-message-id.py

rust-dirstatemap: properly decrement counter for tracked descendants

I found this bug when writing unit tests after the fact for the `DirstateMap`.
We never decremented the tracked descendants counter since we were always
resetting the node data before reading it. This also drops the use of `state`,
in favor of the new API to get that information.

Differential Revision: https://phab.mercurial-scm.org/D12431

from __future__ import absolute_import, print_function

import sys

for line in sys.stdin:
    if line.lower() in ("message-id: \n", "in-reply-to: \n"):
        line = line[:-2]
    print(line, end="")