On Tue 23 Jul 2019 at 15:31:12 (-0400), Michael Stone wrote: > On Tue, Jul 23, 2019 at 02:19:27PM -0500, David Wright wrote: > > I don't see any NUL characters, but x80 as shown below. I'm reading > > the cached message that mutt downloaded from an IMAP server. Is that > > different from you? > > I see it as x80 in mutt and x00 in the raw file on the imap server. I > assume mutt is trying to defang the nul, similar to java's conversion > to 0xc0 0x80, but I haven't actually looked through the code to > confirm.
I don't think mutt is doing that. I downloaded a message directly from my hosting service's IMAP server¹ and that shows <80>, not <00>, just as mutt does. My experience with mutt is that if a NUL is sent in a "legitimate"² manner within an email, it causes truncation. I don't know whether mutt does it or the pager, but as I said elsewhere it doesn't make me happy. I'm not sure whether I can get any "closer" to my IMAP server than that, in order to find whether there's a NUL there; perhaps by logging in using my credentials? That would require some research as I don't normally access the service in that way. One thing we don't know is whether the routes being used by the MTAs to communicate with each other are 8-bit transparent or not. As pointed out by tomás, <80> and <00> only differ in the top bit. > > So it would appear the OP has pasted the Unicode "RIGHT-POINTING > > MAGNIFYING GLASS" character into their postings, which seems somewhat > > reasonable as it's used on the Debian web pages to mark all the > > Message-IDs and references thereto. > > > > Where that gets mangled along the way, I can't guess. but it would see > > that 0x80 is a reasonable choice as that's a Latin-1 Control Character > > with the meaning PAD. > > https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block) > > I'm not entirely surprised that an MUA that is unaware of the changes > to internet mail that have happened since the early 80s (codified back > in 2001) is also unaware of unicode. My last paragraph wasn't necessarily limited to the behaviour of the OP's MUA. It's likely the MTAs are more up-to-date that what is alleged to be a very old MUA. ¹$ curl --url 'imaps://my-hosting-service:993/INBOX;UID=1234' --user 'my-username:my-password' -o Documents/raw-message ²eg as =00 in a quoted-printable encoded message. Cheers, David.
