Re: strange message before sending mail

On 2026-08-19 15:51:42 +0100, Ian Collier via Mutt-dev wrote:
> This seems to mean that the Linux kernel has changed something about
> how the time is obtained when touching a file;

In my Debian bug report against the Linux kernel, Salvatore Bonaccorso
thinks that this is due to

  https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4e40eff0b5737c
  "fs: add infrastructure for multigrain timestamps".

and suggested to use clock_gettime(2) instead of time(2).

> but ultimately it is the time(2) call that is to blame.

Yes, this is what I observed with

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main(void)
{
  while (1)
    {
      struct timespec ts;
      time_t t;

      clock_gettime(CLOCK_REALTIME, &ts);
      t = time(NULL);
      if (ts.tv_nsec < 0)
        exit(1);
      if (t < ts.tv_sec)
        printf("%ld %ld\n", (long) t, (long) ts.tv_sec);
    }
}

On 2026-08-19 13:59:45 -0400, Reed Underwood wrote:
> Yes, you're correct. In glibc 2.44, time() uses a macro which is
> defined as CLOCK_REALTIME_COARSE.

However, is it guaranteed to be less or equal to the time given
by CLOCK_REALTIME? This is not documented. If there isn't such
a guarantee, this will not solve the problem for Mutt, because
by using clock_gettime(CLOCK_REALTIME,...) instead of time(),
the result could be reversed with "old" kernels, for which
timestamps are less accurate.

So I would say that the fix for Mutt would be

 void mutt_stamp_attachment(BODY *a)
 {
-  a->stamp = time(NULL);
+  a->stamp = time(NULL) + 1;
 }

as suggested by Kevin.

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Vincent Lefèvre <[email protected]> - Web: <https://www.vinc17.net/>
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