[Nmh-workers] nmh: format of a mail message file

[pmaydell]

I'm looking at bug 14975:
https://savannah.nongnu.org/bugs/index.php?func=detailitem&item_id=14975

The problem is that scan is complaining about some files in the submitter's
folder, because they begin with the line:
   >From some hugely long line

>From the code, nmh expects files to be
(1) Optionally, a line starting "From ", which is ignored if present
(2) Various lines of the form "Header: contents"
(3) Blank line, then mail body.

But this mail has a '>' at the start, so it doesn't get ignored in (1)
but treated as a header name, and nmh then complains about what it thinks
is an absurdly long header name.

I can't find anything in RFC2822 that puts a limit on header names
(except the overall line length limit) so we ought to handle this
more gracefully in general. But is the message as it stands valid?
That is, should m_getfld() treat initial '>From ' like initial 'From ',
or is whatever is handing the message to rcvstore broken for quoting
the From line like that?

-- PMM