Re: Goals for repo conversion day

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sun, 26 Jan 2014 19:33:12 -0500
> From: "Eric S. Raymond" <esr@thyrsus.com>
> Cc: schwab@linux-m68k.org, emacs-devel@gnu.org

I initially wrote a much longer and detailed response, but eventually
decided to scrap it.  I doubt that this discussion is going anywhere,
since you are determined to do what you think is right, no matter what
I say or show.

So this is a much shorter version, which only touches on a few issues
that I don't yet understand, or where you didn't yet say enough.

> To illustrate my methods, I fixed this by adding those revnos to the 
> ChangeLog section of the map file I enclosed in my last mail (it is
> the file FOSSILS in my conversion directory).  Then I ran a Python
> script called 'decorate.py' that patched in the corresponding action
> stamps.  The point is that I didn't have to do the lookup by hand; the
> fixup took less time to do than to describe.

What will the "patched" ChangeLog entries and log messages look like?
I think it's important that we see that in advance.

> The Bazaar portion of the history isn't the problem, the CVS part is.
> There are many instances in the CVS part of the Emacs history that
> look something like this:
> 
> 1. Eli changes file A and commits it
> 2. Eli changes file B and commits it with an identical change comment.

That's where you are wrong: in the CVS part of Emacs history, the
change comments for these two commits will usually be different.

Here's a typical example:

  ------------------------------------------------------------
  revno: 40047
  committer: Eli Zaretskii <eliz@gnu.org>
  timestamp: Fri 2001-10-19 16:32:49 +0000
  message:
    *** empty log message ***
  modified:
    lisp/ChangeLog
  ------------------------------------------------------------
  revno: 40046
  committer: Eli Zaretskii <eliz@gnu.org>
  timestamp: Fri 2001-10-19 16:30:11 +0000
  message:
    (auto-mode-alist): Associate .indent.pro with
    Fundamental mode.  Suggested by Samuel Padgett
    <spadgett1@nc.rr.com>.
  modified:
    lisp/files.el

Here's another, more complex one (several commits in different
directories, followed by commits of the 2 ChangeLog files describing
those changes):

  ------------------------------------------------------------
  revno: 45027
  committer: Richard M. Stallman <rms@gnu.org>
  timestamp: Tue 2002-04-30 17:57:09 +0000
  message:
    *** empty log message ***
  modified:
    lisp/ChangeLog
    src/ChangeLog
  ------------------------------------------------------------
  revno: 45026
  committer: Richard M. Stallman <rms@gnu.org>
  timestamp: Tue 2002-04-30 17:56:19 +0000
  message:
    (display-time-mail-directory, display-time-mail-function): Doc fixes.
  modified:
    lisp/time.el
  ------------------------------------------------------------
  revno: 45025
  committer: Richard M. Stallman <rms@gnu.org>
  timestamp: Tue 2002-04-30 17:55:02 +0000
  message:
    (Special Properties): Add index entry and xref for tooltips.
  modified:
    lispref/text.texi
  ------------------------------------------------------------
  revno: 45024
  committer: Richard M. Stallman <rms@gnu.org>
  timestamp: Tue 2002-04-30 17:53:39 +0000
  message:
    Comment change.
  modified:
    src/eval.c
    src/fns.c
  ------------------------------------------------------------
  revno: 45023
  committer: Richard M. Stallman <rms@gnu.org>
  timestamp: Tue 2002-04-30 17:48:09 +0000
  message:
    Delete ediff-hook.el page.
  modified:
    lisp/loaddefs.el
  ------------------------------------------------------------
  revno: 45022
  committer: Richard M. Stallman <rms@gnu.org>
  timestamp: Tue 2002-04-30 17:46:40 +0000
  message:
    (Frequire): Error if called while preparing to dump.
  modified:
    src/fns.c
  ------------------------------------------------------------
  revno: 45021
  committer: Richard M. Stallman <rms@gnu.org>
  timestamp: Tue 2002-04-30 17:46:26 +0000
  message:
    (do_autoload): Error if called while preparing to dump.
  modified:
    src/eval.c

There probably are multiple commits with the same commit message, but
they are a tiny minority.

> There is another case common in the Emacs history that can be
> coalesced.  That is: a file modification immediately followed by a
> ChangeLog change describing it

What do you mean by "immediately followed"?  Is there some time window
involved, or some other condition?  If so, please spell them out.

And please take a good look at the examples I pointed to in my
previous message and above: those are very good examples of what most
of our CVS history looks like.  Instead of talking about hypothetical
problems, let's talk about real ones, the ones relevant to _this_
project.

> The other: historically, I've usually worked in collaboration with a
> Mr. Inside, a senior project dev, who checked my work in progress from
> a position of intimate knowledge of the project history.
>
> Congratulations, I think you've elected yourself for that job.

Thanks, but manual QA can only go that far.  I was talking about an
automated one.  There's no way a human, even a genius such as myself,
could inspect any significant portion of a 120k commit history.  There
has to be automated verification of some kind, otherwise the quality
of the result is anyone's guess, your record of converting other
projects notwithstanding.

Besides, I'm very much in doubt that cooperating with me will be a
good idea: we see things too differently, and based on this
discussion, will be unable to convince each other.