Philip Kaludercic <philipk@posteo.net> writes:

> Eli Zaretskii <eliz@gnu.org> writes:
>
>>> Cc: 57400@debbugs.gnu.org, Antoine Kalmbach <ane@iki.fi>
>>> From: Lars Ingebrigtsen <larsi@gnus.org>
>>> Date: Mon, 03 Oct 2022 21:06:57 +0200
>>> 
>>> Do many other VCs have commands to prepare patches like this?
>>
>> Hg and bzr do have such commands.  
>
> Yes, and I would plan to implement it for these as well (even though I
> have never used bzr).
>
>>                                    Others should indeed run vc-diff, I
>> think.
>
> That seem possible, but for that to work I will need a generic way to
> detect the predecessor of a commit and extract a commit message.
> Currently, I am not sure if this can be done.

I had forgotten about `previous-revision', so that was easy and I
decided to fall back to a generic subject as that can be easily revised: