tests/test-revert-flags.t

grep: convert an exception to bytes for a warning message

Caught by pytype:

    File "/mnt/c/Users/Matt/hg/mercurial/commands.py", line 3457, in grep: Function _bytestr.__init__ was called with the wrong arguments [wrong-arg-types]
             Expected: (self, ints: Iterable[int])
      Actually passed: (self, ints: re.error)
      The following methods aren't implemented on re.error:
      __iter__

Differential Revision: https://phab.mercurial-scm.org/D10173

#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 ..