What changelog to preserve at untrivial merging?

[Dmitry Butskoy]

We've changed /bin/mail command source to the new upstream in rawhide 
(see 
https://www.redhat.com/archives/fedora-devel-list/2008-June/msg00628.html 
for more info).

The new source was already in Fedora, under an alternative name of 
"nail". IOW, we currently have /bin/mail provided by mailx-8.1.1, and 
/usr/bin/nail, provided by nail-12.3. Since nail-12.3 supersedes all the 
features of the old undeveloped mailx-8.1.1 (and has the same upstream 
name of "mailx" now), we've decised to switch to it for /bin/mail as well.

As a result, I've copied the "devel" branch of the "nail" package to the 
"devel" branch of the "mailx" package (with some adaptation needed).

The question is: What changelog to preserve?

Both packages have their own history. What changelog preserve in the new 
mailx in rawhide -- the old entries from mailx-8.x, the new entries from 
nail-12.3, or something else?

Regards,
Dmitry Butskoy
http://www.fedoraproject.org/wiki/DmitryButskoy