Why maintain old style ChangeLog?

[Oleksandr Gavenko]

I also ask similar question at (and not completely
satisfied by answers):

http://stackoverflow.com/questions/3712969/why-maintain-traditional-detailed-changelog-in-modern-world-with-svn-mercurial


I read "Sending Patches for GNU Emacs" section of 'info emacs'.

It contains requirement for writing ChangeLog entry
to describe your changes.

I check emacs/trunk/man/trouble.texi (at oldest available in bzr??)
revision:

revno: 25830
committer: Dave Love <xxx@gnu.org>
timestamp: Wed 1999-09-29 15:17:24 +0000

From this revision:

================================================================
The purpose of the change log is to show people where to find what was
changed.  So you need to be specific about what functions you changed;
in large functions, it's often helpful to indicate where within the
function the change was.

On the other hand, once you have shown people where to find the change,
you need not explain its purpose in the change log.  Thus, if you add a
new function, all you need to say about it is that it is new.  If you
feel that the purpose needs explaining, it probably does---but put the
explanation in comments in the code.  It will be more useful there.
================================================================

"where to find what was changed" you can easy done by 'bzr log'.

Or ever more precisely with "bzr log --show-diff".

I think that this statement archaic and search changes
from 13.6 MiB spit Emacs ChangeLogs not so convenient
as 'bzr log' on source root (and don't forget ability
restrict search with date by '-r date1:date2' or dir or fileset).



Second paragraph state that you need describe WHAT
and not write WHY.

For me this is not always right.

You can write source in literate programming style,
so we get a lot of doc and a few of code.

Write comment in code that next line fix behavior on
"another dumb OS with gcc 2.x.x and system ld" ugly.

Much pretty hold this remark as metadata in VCS.

'bzr annotate' gives revision for line
and next you can get log message, full diff.

With Emacs VC you can easy jump deep in history to get
searched log message (vc-annotate-revision-previous-to-line).

I think that commit history is a part of source code.
And must be GPLed. And GPL must require availability
history of changes not only sources! This make program more
easy support and so more free.




But back to the original question.

Does need prepare ChangeLog entry for patch at current time?

And does need maintain ChangeLog at all in view
of modern VCS tools?

--
Best regards!