bug#35443: 27.0.50; Gnus (nnimap) shows "ghost" messages in summary buffer

[Eric Abrahamsen]

On 07/12/19 09:50 AM, Eric Abrahamsen wrote:
> 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.

I think this is the one. I'll push in a bit.