hgweb: use patch.diff() to make sensible diffs (
issue1223,
issue1258)
This gets us git diffs when enabled and doesn't pick erratic file parents.
#!/bin/sh
hg init a
hg clone a b
cd a
echo '[paths]' >> .hg/hgrc
echo 'dupe = ../b' >> .hg/hgrc
hg in dupe | fgrep '../'
cd ..
hg -R a in dupe | fgrep '../'
true