bug#618: 23.0.60; Bazaar support: no revision number with lightweight checkouts

[Dan Nicolaescu <dann@ics.uci.edu>]

Torsten Bronger <bronger@physik.rwth-aachen.de> writes:

  > Hallöchen!
  > 
  > Chong Yidong writes:
  > 
  > > Hi Torsten,
  > >
  > >> In Bazaar lightweight checkouts, Emacs doesn't show the revision
  > >> number in the mode line.
  > >
  > > I think this depends on the branch format, whose default has
  > > changed since this bug was first reported.  For the latest version
  > > of bzr, Emacs shows the revision number in the mode line for
  > > lightweight checkouts (at least for me).
  > 
  > If I remember correctly, someone fixed this shortly after my report.
  > However, we "agreed" on a rather poor solution: Falling back to
  > calling "bzr revno" for every open file.  I've used this solution
  > for many months now.  It slows down Emacs' startup time
  > significantly.  After all, bzr being a Python program, causes a lot
  > of overhead.
  > 
  > Therefore, on the long run, Emacs should use the file system even
  > for lightweight checkouts.  (As long as the branch is local of
  > course.  But this is typical usage lightweight checkouts.)

I checked in a fix, bzr should not be run anymore for lightweight checkouts.