bug#2872: diff from log-view not working for bzr

[Dan Nicolaescu]

Chong Yidong <cyd@stupidchicken.com> writes:

  > > Do a C-x v l on any file under bzr.
  > >
  > > Put the point on some random log entry and type 
  > > d
  > > And empty *vc-diff* window will appear.
  > 
  > I've checked in a fix.

The fix was too radical, log entries for merges don't work anymore.
They have a format like:

    ------------------------------------------------------------
    revno: 123.1.4
    committer: 
    branch nick: blah
    timestamp: blah
    message:
      blah
        ------------------------------------------------------------
        revno: 12.3.123