Re: Mail mode vs message mode

[Stefan Monnier <monnier@iro.umontreal.ca>]

>>>> (defcustom message-foo
>>>> (let ((def mail-foo))
>>>> (if (acceptable def) def fallback))
>>>> ...)
>>> That kind of defeats the purpose.
>> Why?

> Isn't the entire purpose of using a default value of `mail-foo' to pick
> up any user customizations of mail-foo in .emacs (otherwise it'd be easy
> enough to just use a literal "> " as a default for message-yank-prefix)?

> So if the user sets mail-yank-prefix to "   ", but your (acceptable ...)
> test rejects that because it looks wrong, then the purpose has (to some
> extent) been defeated...

Clearly, we'd want the `acceptable' test to only reject the few default
settings of previous Emacsen that are not acceptable and accept
anything else.  So we'd only ignore user's configurations if they have
their mail-foo var customized to one of those older default values.

For those, they'll have to set message-foo explicitly instead.


        Stefan