Re: [PATCH] Add checks for new and tmp directories to mx_is_maildir()

Gero Treuner wrote in
 <[email protected]>:
 |On Fri, Feb 06, 2026 at 02:37:36PM +0100, Alejandro Colomar via Mutt-dev \
 |wrote:
 ...
 |> Except that maybe with fstatat(2) (as Crystal said) it could be readable
 |> --we'd have to see the code, though--.
 |> 
 |> readability >>> optimizations
 |
 |Thank you and others for the feedback.
 |
 |A quick research shows that fstatat(2) isn't a good option:
 |
 |1) Even on Linux it was introduced no earlier than with glibc 2.4, so
 |   this makes a case for portability fiddling with automake etc.
 |
 |2) The directory needs to be opened with a file descriptor, which adds
 |   resource handling.
 |   I don't see consistency of the directory in the event that by
 |   mounting etc. the file system changes as a benefit here. IMO it is
 |   fine to fail for a test of a mail folder when something looks fishy.
 |   (Otherwise the test could succeed for a place which isn't available
 |   any more.)

Btw i changed to Courier mail server style names in 2017,
which i think also dovecot uses (or surely used to use
in 2017 when i looked around).  "I" am *not* entirely
compatible with the behavior that they document for what i
thought was the quasi standard of Maildir, their document, as
attached, because they require renaming time.MusecPpid.host /
time.MusecPpid_unique.host to time.MusecPpidVdevIino.host,S=cnt /
time.MusecPpidVdevIino_unique.host,S=cnt when moving from tmp/
to new/, and more a bit "strange things" (i have never looked
when the document was created; must be after 1996 though, in
BSD O_EXCL was implemented around July 1983, so some TOCTOU
in the document must likely be NFS related, but then the
create+link+stat+test-link-count dance was also known quite a bit
before Maildir was invented, i would think).
Anyhow, "dev" and "ino" are part of their filename style.

 |But the same gain of readability could probably be achieved by other
 |means. (Let's see when I'll come back to puzzling ...)
 ...

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)