Add dirstate.pathto and localrepo.pathto. Every time util.pathto is called, we have to pass the repo root and the repo cwd. dirstate.pathto is a simple convenience function that knows about the root and the cwd arguments. It's still possible to pass the cwd as an optimization. localrepo.pathto is a convenience function that just calls dirstate.pathto, just like localrepo.getcwd. dirstate.pathto becomes a single point that converts most (all?) paths from the internal representation to some OS-specific relative path for display purposes.

#!/bin/sh

echo "[extensions]" >> $HGRCPATH
echo "patchbomb=" >> $HGRCPATH

hg init
echo a > a
hg commit -Ama -d '1 0'

hg email --date '1970-1-1 0:1' -n -f quux -t foo -c bar tip | \
  sed -e 's/\(Message-Id:.*@\).*/\1/'

echo b > b
hg commit -Amb -d '2 0'

hg email --date '1970-1-1 0:2' -n -f quux -t foo -c bar -s test 0:tip | \
  sed -e 's/\(Message-Id:.*@\|In-Reply-To:.*@\).*/\1/'