manifest: define and implement rev() on manifestlog
Various code is accessing repo.manifestlog._revlog - a private
attribute. This bypasses our interface and makes it difficult to
implement non-revlog manifest storage.
This commit adds a rev() method to the manifestlog interface and
class and teaches callers to use it.
Ideally this method wouldn't exist, as very few consumers should
need to resolve the revision number of a manifest. Again, the
primary goal of interface work is to establish and use interfaces
first and to improve them later.
Differential Revision: https://phab.mercurial-scm.org/D3882
#if no-windows no-osx
$ mkdir -p xdgconf/hg
$ echo '[ui]' > xdgconf/hg/hgrc
$ echo 'username = foobar' >> xdgconf/hg/hgrc
$ XDG_CONFIG_HOME="`pwd`/xdgconf" ; export XDG_CONFIG_HOME
$ unset HGRCPATH
$ hg config ui.username 2>/dev/null
foobar
#endif