bug#34898: 24.4; `message-separator' face only works for default value of `mail-header-separator'

[Eric Abrahamsen <eric@ericabrahamsen.net>]

"Basil L. Contovounesios" <contovob@tcd.ie> writes:

> Eric Abrahamsen <eric@ericabrahamsen.net> writes:
>
>> The value of `mail-header-separator' gets added to
>> `message-font-lock-keywords', which does the actual fontification. Using
>> setq to change the value of `mail-header-separator' did not change the
>> font lock keyword, despite setting the variable before message.el is
>> loaded (or is it pre-loaded?). Using the customize interface to set
>> `mail-header-separator' *does* work as expected.
>
> 0. emacs -Q
> 1. (setq mail-header-separator "--") C-j
> 2. C-x m
>
> Note that setting mail-header-separator before loading message.el works
> as expected.
>
> 3. M-x customize-variable RET mail-header-separator RET
> 4. Change value from "--" to "--foo--"
> 5. C-c C-c
> 6. C-x m
>
> Note that "--foo--" gets inserted, but message-font-lock-keywords still
> holds the value that mail-header-separator had at the time message.el
> was loaded.
>
> Since mail-header-separator lacks a custom setter, it makes no
> difference whether you use setq or Customize, so long as its value is
> changed before message.el is loaded.  Otherwise, you have to reevaluate
> and reapply message-font-lock-keywords.

I didn't try with emacs -Q, probably something in my setup ends up
loading message.el at startup.

Thanks,
Eric