notmuch-mode: Emails with PDF attachments incorrectly tagged as text/plain expose a few issues

[Tomi Ollila]

On Mon, Apr 06 2020, David Bremner wrote:

> Leo Gaspard <leo at gaspard.io> writes:
>
>> David Bremner <david at tethera.net> writes:
>>
>>> Leo Gaspard <leo at gaspard.io> writes:
>>>
>>>> Hello,
>>>>
>>>> I have recently started conversing with someone whose email client
>>>> incorrectly tags PDF attachments as text/plain.
>>>>
>>>
>>> Hi Leo;
>>>
>>> As I mentioned on IRC, we most likely need a reproducer message before
>>> making any progress on this. Maybe you can ask your correspondent to
>>> send you a shareable message, then sanitize the addesses in the headers.
>>
>> So, I've just been able to re-create at least the “freeze on reply” isue
>> with the email attached. The image doesn't get corrupted when saving,
>> though, so I'm not sure it'll be enough to fix both issues, but
>> hopefully fixing this one would fix the other one too.
>>
>> If you try to notmuch-show on the attached email, then hit `r`, you
>> should notice the image being included verbatim in the text/plain
>> output, and when hitting C-c C-c it should start freezing emacs.
>>
>> Hope that helps!
>>   Leo
>
> Probably the rest of the list hasn't seen the message yet, but I did try
> it out. ...

Rest of the list hasn't seen the message (yet?) as the body is 440805 bytes
in size (and there is limit in the mailing list) and it is hanging in 
moderator queue. I am not too enthusiastic to bloat the mailing list
archive with just a large test message (but am not against is there more
people who do think that it is a good idea).

Tomi

> ... It doesn't actually hang emacs for me (C-g enough times gets me
> back). I agree that inserting binary data into the buffer is probably
> not a great idea.  I'm not sure offhand how notmuch should detect
> mislabeled parts. Perhaps it should just refuse to insert large parts as
> reply text.
>
> d