Re: When do we merge the commits from emacs-25 onto master?

[Paul Eggert]

On 11/24/2015 10:32 AM, Eli Zaretskii wrote:
> > From: David Engster <address@hidden>
> > Date: Mon, 23 Nov 2015 23:43:21 +0100
> > Cc: Paul Eggert <address@hidden>, emacs-devel <address@hidden>
> >
> > We still haven't figured out how to deal with the generated ChangeLogs,
> > so I'm not sure we should merge at the moment.
> Would it work to somehow teach gitmerge.el to use the (fixed) text
> from ChangeLog.2 as the merge-commit log message, instead of the
> original log message at emacs-25 commit time?

A clever idea, and something like that might work, but it sounds 
brittle. Often, changes to ChangeLog.2 aren't isolated to single 
commits, and offhand I don't see how in general to figure out which 
parts of ChangeLog.2 should be matched to which commits.

How about the following idea instead.  Let's put the emacs-25 branch in 
charge of ChangeLog.2, and put the master branch in charge of a new file 
ChangeLog.3 that exists only in the master branch. We can do this by 
updating CHANGELOG_HISTORY_INDEX_MAX to 3 only in the master.  Then 
merges from emacs-25 to master should be trivial, as people who want to 
manually edit ChangeLog.2 or to update it via 'make change-history' 
should do so only in the emacs-25 branch. We'll need to modify 'make 
ChangeLog' so that in the master it ignores commit messages merged from 
the emacs-25 branch (I assume this is doable but I haven't checked 
this). Backporting changes will still be a hassle (we'll need to run 
'make change-history' in the master, and then manually update 
ChangeLog.3 to remove references to the changes being backported to 
emacs-25), but that's OK.