cmdutil: changeset_printer: use methods of filectx/changectx.
This allows extensions that modify changeset metadata (e.g.
description) by overriding methods of changectx to get consistent
behavior from all log-like commands, regardless of whether templates
or styles are used. Without this, overriding changectx methods works
if you use styles or templates, but not with default log format.
This meant adding filectx.extra() for consistency with changectx.
#!/bin/sh
"$TESTDIR/hghave" symlink || exit 80
echo "[extensions]" >> $HGRCPATH
echo "mq=" >> $HGRCPATH
hg init
hg qinit
hg qnew base.patch
echo a > a
echo b > b
hg add a b
hg qrefresh
$TESTDIR/readlink.py a
hg qnew symlink.patch
rm a
ln -s b a
hg qrefresh --git
$TESTDIR/readlink.py a
hg qpop
hg qpush
$TESTDIR/readlink.py a
hg qnew removesl.patch
hg rm a
hg qrefresh --git
hg qpop
hg qpush
hg st -c