bug#72341: VC: CVS template lines not stripped when committing

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 30 Jul 2024 16:35:29 +0300
> Cc: 72341@debbugs.gnu.org
> From: Dmitry Gutov <dmitry@gutov.dev>
> 
> On 29/07/2024 15:34, Eli Zaretskii wrote:
> > I'm unsure how to proceed with this.  My bother is that this is a
> > definite change in behavior wrt what VC did until now.  Users of VC
> > might be unaware of this removal, and could start some log lines with
> > the prefix, which will mysteriously disappear from the log message.
> > 
> > Dmitry, WDYT?  Maybe we should add this removal guarded by a user
> > option, by default off?  Or maybe we can identify where the template
> > starts and ends, and only remove in that region?
> 
> If we do this, we'd only remove the lines starting with "CVS:". We could 
> also add special syntax highlighting for them. That would probably be 
> enough.

Agreed.

> Then vc-cvs-checkin would additionally process the commit message string 
> returned by log-edit-extract-headers.
> 
> Note that it seems we only handle "templates" for CVS and RCS, so there 
> is no prior art for implementing this feature.

Right.  Patches welcome to implement this.