splitting ChangeLogs

splitting ChangeLogs

[Juanma Barranquero]

src/Changelog is a massive 1.12 MiB, and lisp/ChangeLog a slightly
less impressive 0.86 MiB.

It's OK to split them at the following point?

2010-05-07  Chong Yidong  <cyd@stupidchicken.com>

        * Version 23.2 released

If so, which one should keep history, i.e.,

  copy ChangeLog Changelog.11
  ;; edit and trim both files
  bzr add ChangeLog.11
  bzr commit -m "..."

or

  bzr mv ChangeLog ChangeLog.11
  copy ChangeLog.11 ChangeLog
  ;; edit and trim both files
  bzr add ChangeLog
  bzr commit -m "..."

    Juanma

Re: splitting ChangeLogs

[Eli Zaretskii]

> From: Juanma Barranquero <lekktu@gmail.com>
> Date: Wed, 6 Apr 2011 03:49:39 +0200
> 
> src/Changelog is a massive 1.12 MiB, and lisp/ChangeLog a slightly
> less impressive 0.86 MiB.
> 
> It's OK to split them at the following point?
> 
> 2010-05-07  Chong Yidong  <cyd@stupidchicken.com>
> 
>         * Version 23.2 released

Why not at 23.3?

> If so, which one should keep history, i.e.,
> 
>   copy ChangeLog Changelog.11
>   ;; edit and trim both files
>   bzr add ChangeLog.11
>   bzr commit -m "..."
> 
> or
> 
>   bzr mv ChangeLog ChangeLog.11
>   copy ChangeLog.11 ChangeLog
>   ;; edit and trim both files
>   bzr add ChangeLog
>   bzr commit -m "..."

The latter, I think.

Re: splitting ChangeLogs

[Juanma Barranquero]

On Wed, Apr 6, 2011 at 05:00, Eli Zaretskii <eliz@gnu.org> wrote:

> Why not at 23.3?

There's no entry for "Branch for 23.3" in the ChangeLogs (I don't know
why there's an entry for 23.2, as it wasn't branched from trunk, but
still...)

> The latter, I think.

Aha, thanks.

    Juanma

Re: splitting ChangeLogs

[Stephen J. Turnbull]

Eli Zaretskii writes:
 > Glenn Morris suggests:

 > >   bzr mv ChangeLog ChangeLog.11
 > >   copy ChangeLog.11 ChangeLog
 > >   ;; edit and trim both files
 > >   bzr add ChangeLog
 > >   bzr commit -m "..."
 > 
 > The latter, I think.

I think it would be preferable to use bzr cp, but it doesn't seem to
exist.

If not, the above is the TRT.

Re: splitting ChangeLogs

[Glenn Morris]

Eli Zaretskii wrote:

>>   copy ChangeLog Changelog.11
>>   ;; edit and trim both files
>>   bzr add ChangeLog.11
>>   bzr commit -m "..."
>> 
>> or
>> 
>>   bzr mv ChangeLog ChangeLog.11
>>   copy ChangeLog.11 ChangeLog
>>   ;; edit and trim both files
>>   bzr add ChangeLog
>>   bzr commit -m "..."
>
> The latter, I think.

Shouldn't ChangeLog should keep its current file-id, so that eg merged
entries from emacs-23 go to the correct file? The current lisp/ChangeLog
has a log that goes back to 1999.

PS Why does it matter if ChangeLogs get larger than 1MB?

Re: splitting ChangeLogs

[Stephen J. Turnbull]

Glenn Morris writes:

 > Shouldn't ChangeLog should keep its current file-id, so that eg merged
 > entries from emacs-23 go to the correct file? The current lisp/ChangeLog
 > has a log that goes back to 1999.

Argh.  Got that backward, myself (git-thinking strikes!)  Yes, that's
the right thing to do.  ChangeLog.11 will presumably never change in
the future, so its identity is not terribly interesting.

Re: splitting ChangeLogs

[Leo]

On 2011-04-06 12:58 +0800, Stephen J. Turnbull wrote:
> Argh.  Got that backward, myself (git-thinking strikes!)  Yes, that's
> the right thing to do.  ChangeLog.11 will presumably never change in
> the future, so its identity is not terribly interesting.

Have people considered removing ChangeLogs, adopting a convention for
writing commit messages and (maybe) regenerating them for the release
from the commit history?

Leo

Re: splitting ChangeLogs

[Eli Zaretskii]

> From: Leo <sdl.web@gmail.com>
> Cc: Glenn Morris <rgm@gnu.org>,  Juanma Barranquero <lekktu@gmail.com>,  Eli Zaretskii <eliz@gnu.org>,  emacs-devel@gnu.org
> Date: Wed, 06 Apr 2011 13:05:09 +0800
> 
> Have people considered removing ChangeLogs

Yes, many times.  See the archives.

Re: splitting ChangeLogs

[Eli Zaretskii]

> From: Glenn Morris <rgm@gnu.org>
> Cc: Juanma Barranquero <lekktu@gmail.com>,  emacs-devel@gnu.org
> Date: Wed, 06 Apr 2011 00:01:20 -0400
> 
> >>   bzr mv ChangeLog ChangeLog.11
> >>   copy ChangeLog.11 ChangeLog
> >>   ;; edit and trim both files
> >>   bzr add ChangeLog
> >>   bzr commit -m "..."
> >
> > The latter, I think.
> 
> Shouldn't ChangeLog should keep its current file-id, so that eg merged
> entries from emacs-23 go to the correct file?

I thought the ChangeLog entries from the emacs-23 branch are merged
manually.  If they are merged automatically, then you are right.

Re: splitting ChangeLogs

[Eli Zaretskii]

> From: Juanma Barranquero <lekktu@gmail.com>
> Date: Wed, 6 Apr 2011 05:24:27 +0200
> Cc: emacs-devel@gnu.org
> 
> On Wed, Apr 6, 2011 at 05:00, Eli Zaretskii <eliz@gnu.org> wrote:
> 
> > Why not at 23.3?
> 
> There's no entry for "Branch for 23.3" in the ChangeLogs

That in itself seems like some kind of snafu.  There should be such an
entry, since I now understand that the ChangeLog is also merged
automatically from the branch.

> (I don't know why there's an entry for 23.2, as it wasn't branched
> from trunk, but still...)

That's CVS-speak ;-)  With bzr we shouldn't have such problems.  The
entry should be there, or else years from now, you won't be able to
know when was Emacs 23.3 released without having the branch in your
local sandbox.

Re: splitting ChangeLogs

[Eli Zaretskii]

> From: "Stephen J. Turnbull" <turnbull@sk.tsukuba.ac.jp>
> Cc: Juanma Barranquero <lekktu@gmail.com>,
>     emacs-devel@gnu.org
> Date: Wed, 06 Apr 2011 12:43:24 +0900
> 
> Eli Zaretskii writes:
>  > Glenn Morris suggests:
> 
>  > >   bzr mv ChangeLog ChangeLog.11
>  > >   copy ChangeLog.11 ChangeLog
>  > >   ;; edit and trim both files
>  > >   bzr add ChangeLog
>  > >   bzr commit -m "..."
>  > 
>  > The latter, I think.
> 
> I think it would be preferable to use bzr cp, but it doesn't seem to
> exist.

What would it do, if it existed, that a simple `cp' won't?

Re: splitting ChangeLogs

[Stephen J. Turnbull]

Eli Zaretskii writes:
 > > I think it would be preferable to use bzr cp, but it doesn't seem to
 > > exist.
 > 
 > What would it do, if it existed, that a simple `cp' won't?

It would arrange the history of ChangeLog be attached to both
ChangeLog and ChangeLog.11.

Re: splitting ChangeLogs

[Juanma Barranquero]

On Wed, Apr 6, 2011 at 06:01, Glenn Morris <rgm@gnu.org> wrote:

> PS Why does it matter if ChangeLogs get larger than 1MB?

On one hand, it's faster to work with a smaller file. On the other,
and more importantly, committing changes that include the ChangeLog is
also faster.

    Juanma

Re: splitting ChangeLogs

[Juanma Barranquero]

On Wed, Apr 6, 2011 at 11:19, Eli Zaretskii <eliz@gnu.org> wrote:


> That's CVS-speak ;-)  With bzr we shouldn't have such problems.  The
> entry should be there, or else years from now, you won't be able to
> know when was Emacs 23.3 released without having the branch in your
> local sandbox.

OK. I think I'll add the entries and split the files.

    Juanma

Re: splitting ChangeLogs

[Eli Zaretskii]

> From: "Stephen J. Turnbull" <turnbull@sk.tsukuba.ac.jp>
> Cc: lekktu@gmail.com,
>     emacs-devel@gnu.org
> Date: Wed, 06 Apr 2011 18:39:40 +0900
> 
> Eli Zaretskii writes:
>  > > I think it would be preferable to use bzr cp, but it doesn't seem to
>  > > exist.
>  > 
>  > What would it do, if it existed, that a simple `cp' won't?
> 
> It would arrange the history of ChangeLog be attached to both
> ChangeLog and ChangeLog.11.

Sorry, I don't follow.  "History" here means the sequence of revisions
where the file was modified, right?  If so, then past revisions are
already frozen in the repo's DAG, and each revision there is
immutable, right?  IOW, if a certain revision changed only file A,
there's no way to retroactively change it so that it appears to modify
both A and B, right?  It is also not possible to add revisions that
were not originally there, right?  So what am I missing?

Re: splitting ChangeLogs

[Stefan Monnier]

>> copy ChangeLog Changelog.11
>> ;; edit and trim both files
>> bzr add ChangeLog.11
>> bzr commit -m "..."
>> 
>> or
>> 
>> bzr mv ChangeLog ChangeLog.11
>> copy ChangeLog.11 ChangeLog
>> ;; edit and trim both files
>> bzr add ChangeLog
>> bzr commit -m "..."

> The latter, I think.

But that would mean that merges from emacs-23 will go to
ChangeLog.11.  So I think it should be the former instead.


        Stefan

Re: splitting ChangeLogs

[Juanma Barranquero]

On Wed, Apr 6, 2011 at 17:19, Stefan Monnier <monnier@iro.umontreal.ca> wrote:

> But that would mean that merges from emacs-23 will go to
> ChangeLog.11.  So I think it should be the former instead.

I've already done the former. src/ChangeLog and lisp/ChangeLog should
have their original file-ids, unless I've screwed something.

    Juanma

Re: splitting ChangeLogs

[Stefan Monnier]

> I thought the ChangeLog entries from the emacs-23 branch are merged
> manually.  If they are merged automatically, then you are right.

The merge is automatic, and the resulting conflicts can either be
resolved automatically (e.g. via smerge-resolve or a bzr plugin),
or manually.


        Stefan

Re: splitting ChangeLogs

[Stefan Monnier]

>> > I thought the ChangeLog entries from the emacs-23 branch are merged
>> > manually.  If they are merged automatically, then you are right.
>> The merge is automatic, and the resulting conflicts can either be
>> resolved automatically (e.g. via smerge-resolve or a bzr plugin),
>> or manually.
> What conflicts? there are no conflicts (assuming you have the
> changelog_merge plugin).

Well, in my view, the changelog_merge plugin resolves conflicts
resulting from a merge more than it performs a merge, but I don't know
if the implementation matches my mental image of it.


        Stefan

Re: splitting ChangeLogs

[Glenn Morris]

Juanma Barranquero wrote:

> On Wed, Apr 6, 2011 at 06:01, Glenn Morris <rgm@gnu.org> wrote:
>
>> PS Why does it matter if ChangeLogs get larger than 1MB?
>
> On one hand, it's faster to work with a smaller file. On the other,
> and more importantly, committing changes that include the ChangeLog is
> also faster.

OK. I noticed that with CVS, haven't really noticed it with bzr though.

Re: splitting ChangeLogs

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: rgm@gnu.org,  lekktu@gmail.com,  emacs-devel@gnu.org
> Date: Wed, 06 Apr 2011 12:53:21 -0400
> 
> > What conflicts? there are no conflicts (assuming you have the
> > changelog_merge plugin).
> 
> Well, in my view, the changelog_merge plugin resolves conflicts
> resulting from a merge more than it performs a merge, but I don't know
> if the implementation matches my mental image of it.

It doesn't.  changelog_merge completely replaces the default merge
method.  In fact, it falls back on the default method if its own
fails.

Re: splitting ChangeLogs

[Stephen J. Turnbull]

Eli Zaretskii writes:

 > So what am I missing?

The logs and diffs.

Since I'm not Andreas, I guess I can't leave it at that.<wink>

If before for splitting ChangeLog, bzr log ChangeLog shows N
revisions, after either of the procedures shown, one of ChangeLog and
ChangeLog.11 has 1 revision, and the other has N+1.  bzr diff does
nothing useful with the newly added file.  With a hypothetical bzr cp,
both would have N+1, and bzr diff would work on both.

This isn't terribly useful for ChangeLogs whose entries are (almost)
immutable, of course, but it is very useful in cases where a source
file containing multiple functions is refactored into two files.

I could have sworn bzr had this feature, but maybe I'm thinking of
Mercurial (which definitely has it).

Re: splitting ChangeLogs

[Eli Zaretskii]

> From: "Stephen J. Turnbull" <turnbull@sk.tsukuba.ac.jp>
> Cc: lekktu@gmail.com,
>     emacs-devel@gnu.org
> Date: Thu, 07 Apr 2011 09:36:27 +0900
> 
> Eli Zaretskii writes:
> 
>  > So what am I missing?
> 
> The logs and diffs.
> 
> If before for splitting ChangeLog, bzr log ChangeLog shows N
> revisions, after either of the procedures shown, one of ChangeLog and
> ChangeLog.11 has 1 revision, and the other has N+1.  bzr diff does
> nothing useful with the newly added file.  With a hypothetical bzr cp,
> both would have N+1, and bzr diff would work on both.

I think I see the light now.  You are saying that with "bzr cp", the
DAG will still be (almost) the same, except that "bzr diff" and other
commands will simply act _as_if_ the new ChangeLog had the same
history as the old one.  Right?

Re: splitting ChangeLogs

[Stephen J. Turnbull]

Eli Zaretskii writes:

 > I think I see the light now.  You are saying that with "bzr cp",
 > the DAG will still be (almost) the same, except that "bzr diff" and
 > other commands will simply act _as_if_ the new ChangeLog had the
 > same history as the old one.  Right?

Yes.  Although I wouldn't use "as if" to describe an equivalence like
this.  For all practical purposes, it really does have the same
history.