Lars Ingebrigtsen <larsi@gnus.org> writes:

> Eric Abrahamsen <eric@ericabrahamsen.net> writes:
>
>> Which is obviously insufficient. I've since changed it to:
>>
>> "\\([A-Z][[:ascii:]-]+: \\)"
>>
>> Which works better, but also seems susceptible to breakage due to
>> ignorance. A quick scan doesn't turn up any `mail-header-regexp'
>> variables or `this-is-a-mail-header-p' functions -- does the above
>> regexp seem reasonable?
>
> Headers are case insensitive...  but not all characters in the [:ascii:]
> set are allowed; far from it.  [:alnum:] is closer, but with - and...
> er...  stuff...  One of the RFCs probably has the definition.  :-)

Oh, good point. RFC2822 says chars 33 to 126, inclusive, minus the
colon. So I guess it's "[!-9,;-~]+: ", unlikely as some of those
characters seem.

Now I'm working with the attached diff.

Eric