Strange message from "bzr pull"

[Eli Zaretskii]

I've just created a local Bazaar repository for Emacs and initialized
and bootstrapped the quickfixes branch, as described in
BzrForEmacsDevs emacswiki page.  This is on a GNU/Linux machine with
bzr 2.0.0.

After bootstrapping, I chdir'ed back to trunk and typed "bzr pull".
Note that there were no changes whatsoever in this repository, so all
I expected to see was the usual "Now on revision NNNN." message.
Instead, I saw this:

   M  lisp/ChangeLog
   M  lisp/vc-bzr.el
  All changes applied successfully.
  Now on revision 99211.

In CVS, the "M" marker meant that I have local uncommitted changes.
But I don't have such changes here, at least not consciously.  So what
does this message mean, and how do I dig into the reasons for it (if
there are any)?