Glenn Morris wrote:

> The file ChangeLog.1 in the repo contains a mixture of new, generated
> entries applying to the entire Emacs tree, and (before a certain magic
> date) older, hand-written entries that only apply to the top-level
> (essentially) directory. I think it's pretty confusing to have both
> things in the same file.

If you prefer a sharper division between pre-April-7 and post-April-7 entries, 
we can move the latter entries into a new file ChangeLog.2.  That is, 
ChangeLog.1 and ChangeLog.2 would both be hand-maintained, ChangeLog.1 would 
contain top-level entries predating April 7, and ChangeLog.2 would contain all 
entries between April 7 and the most recent 'make change-history'.  Please see 
the first attached patch.  (I haven't tested it.)

> Suppose we improve/change the ChangeLog generation script, and want to
> regenerate the generated ChangeLog. It will be difficult to extract the
> various corrections that have been applied by hand to the generated
> entries.

That shouldn't be a problem, as the newly-generated ChangeLog shouldn't include 
any hand-corrected entries.  All hand-corrected entries should be in ChangeLog.1 
(or ChangeLog.2, etc.).

> I had assumed that "ChangeLog" would be a top-level generated file that
> would grow and grow with time, and would always be generated from
> scratch whenever needed

That's basically right, except that the generated "ChangeLog" file also shrinks 
after 'make change-history' is run.

> with entries always starting from Apr 7 2015.

No, the automatically-generated 'ChangeLog' entries start from the last time 
'make change-history' was run.

> erc uses a non-standard scheme where .YY contains the entries for 20YY.

Ah, sorry, I didn't know that.  We could proceed as you suggest, though we'd 
need to add a line to Makefile.in.  Please see the second attached patch (it's 
so large that I gzipped it).  (I haven't tested this either.)