C-x v i bug

[Dan Nicolaescu]

Martin Geisler <mg at lazybytes.net> writes:

  > Dan Nicolaescu <dann at ics.uci.edu> writes:
  > 
  > > Let's first talk about the original problem that started this
  > > discussion.
  > >
  > > When a file in a directory that is under mercurial control is opened
  > > in emacs, emacs runs "hg status FILE" so that it knows if it's
  > > registered or not, if it's modified, etc.
  > >
  > > Any user settings in .hgrc should be irrelevant to the above. Right?
  > 
  > Right. Many people use the color extension to get better feedback from
  > 'hg status', but if Emacs sets TERM=dumb, then the extension will
  > disable itself. I'm just mentioning color to say that there are useful
  > extensions out there that modify even basic commands like 'hg status'.
  > 
  > > It's desirable that this is as fast as possible, so processing .hgrc,
  > > initializing plugins will just waste time.
  > > After that emacs will want to know the version number for the file, for that
  > > it runs "hg log -l1 FILE", and parse it from the output.
  > > Any user settings in .hgrc should be irrelevant for this command.  Right?
  > 
  > Right, and it's even quite important that you disable localization (run
  > hg with LANGUAGE=C in the environment). Otherwise you'll end up parsing:
  > 
  >   % hg log -l1 README
  >   ændring:     9586:a41f2840f9c6
  >   bruger:      Lee Cantey <lcantey at gmail.com>
  >   dato:        Tue Oct 13 12:27:50 2009 -0700
  >   uddrag:      README: revert accidental commit
  > 
  > The user could also very well have installed a different default style
  > by setting ui.style. On the command line it's done line this:

Thank you, this was very useful in taking care of some issues in emacs.

  >   % hg log -l1 README --style=compact
  >   9586   a41f2840f9c6   2009-10-13 12:27 -0700   lcantey
  >     README: revert accidental commit
  > 
  > > [too bad that the status and version number are not available from a
  > > single command...]
  > 
  > Well, you know, files don't really have a version number with modern
  > version control systems. The entire tree has a version number... You can
  > of course ask about when a file was last touched, but I think that
  > information is getting more and more irrelevant these days.

In emacs the generic Version Control layer needs a version number in some case.
Here's an example from a bug report:

cd  /tmp
mkdir hgtest2
cd hgtest2
hg init
echo foo > foo.txt
hg add foo.txt
hg commit -m "Added foo.txt"
hg branch bar
echo bar > foo.txt
hg commit -m "Changed foo to bar"
hg update -r default
echo frobozz > frobozz.txt
hg add frobozz.txt
hg commit -m "Added frobozz.txt"


now open the file mkdir /tmp/hgtest2/foo.txt and ask to see the
annotated version, emacs does that by running

hg annotate -r REVISION foo.txt

How can REVISION be obtained in this case?
It should be "0", but
hg log -l1 foo.txt
does not show that...

Thanks!