bug#72735: 31.0.50; [PATCH] Make more bug-reference variables customizeable

[Tassilo Horn <tsdh@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

Hi all,

>> I noticed that there are other variable such as
>> bug-reference-setup-from-mail-alist that should be change similarly.
>
> Which ones, specifically?
>
> And let's get Tassilo (CC'ed) on board of this discussion.

As Eli already mentioned, bug-reference-url-format is usually set via a
file local variables section or programatically so neither a defcustom
nor a default value makes sense.

Wrt. bug-reference-setup-from-mail-alist,
bug-reference-setup-from-irc-alist, and
bug-reference-setup-from-vc-alist: yes, they could be defcustoms but
their entries can all (and are likely to) contain functions which are
hard to specify in the defcustom interface.  I've thought it wouldn't be
needed.  After all, bug-reference is a programmer's tool.

Wrt. bug-reference-forge-alist: if it became a defcustom and a user
would set it, she wouldn't see updates (like support for some new forge)
in its default value anymore because their old saved custom value
overrides the new default value.  It's much better to add new entries
programatically using add-to-list or push/cl-pushnew.  Of course, one
could split the variable in some *-default-alist defvar and a defcustom
*-alist where the latter is meant for user customization but I think
it's not worth the added complexity here.

So I'd rather keep it as-is.

Bye,
  Tassilo