tests/test-revert-flags.t

revsets: define a none() revset

This can be useful for default values in corp-wide configuration
(e.g. for commits to hide, which defaults to none()), and perhaps in
scripts. I named it none() rather than empty() to match all().

Differential Revision: https://phab.mercurial-scm.org/D3713

#require execbit

  $ hg init repo
  $ cd repo
  $ echo foo > foo
  $ chmod 644 foo
  $ hg ci -qAm '644'

  $ chmod 755 foo
  $ hg ci -qAm '755'

reverting to rev 0

  $ hg revert -a -r 0
  reverting foo
  $ hg st
  M foo
  $ hg diff --git
  diff --git a/foo b/foo
  old mode 100755
  new mode 100644

  $ cd ..