diff: don't show function name by default
We'd mistakenly made the -p option always on, which meant there was no
way to turn it off. It also meant that we were sometimes splitting
multibyte characters in function name, which isn't a good default.
#!/bin/sh
hg init
echo % should fail
hg add .hg/00changelog.i
mkdir a
echo a > a/a
hg ci -Ama
ln -s a b
echo b > a/b
echo % should fail
hg add b/b
echo % should succeed
hg add b
echo % should still fail - maybe
hg add b/b
exit 0