bug#20717: attribution of gitmerge.el merged entries in generated ChangeLog

[Glenn Morris]

Glenn Morris wrote:

> After using M-x gitmerge (which seems v nice, BTW), 'make ChangeLog'
> creates a file with contents:
>
> 2015-06-01  Glenn Morris  <rgm@...>
>
>    Merge from origin/emacs-24
>    8b5f2f4 * doc/emacs/emacs.texi: Update the ISBN of the Emacs manual.
>
> The merged entries should be listed under the name of the original
> author(s), not the name of the person who did the merge.

Oh, I see we actually get both. The above entry on the date of the
merge, and another entry (with the correct attribution) on the date the
change was originally made (which of course has zero relation to the
merge date) in the original branch. And changes that were skipped from
the merge are still included. What a confusing mess.