Re: Bug? "fstat64(f, &sb) < 0 && S_ISREG(sb.st_mode)"

[Eduardo Bustamante <dualbus@gmail.com>]

Also, inspecting bash code, this seems to be code to figure out if the
file was changed from a non-regular file to a regular file between the
stat and the open, so I'd say it's indeed a bug, but the problem is
not the &&, but testing the wrong return code.

From bash redir.c

 631   /* OK, the open succeeded, but the file may have been changed from a
 632      non-regular file to a regular file between the stat and the open.
 633      We are assuming that the O_EXCL open handles the case where FILENAME
 634      did not exist and is symlinked to an existing file between the stat
 635      and open. */
 636
 637   /* If we can open it and fstat the file descriptor, and neither check
 638      revealed that it was a regular file, and the file has not
been replaced,
 639      return the file descriptor. */
 640   if ((fstat (fd, &finfo2) == 0) && (S_ISREG (finfo2.st_mode) == 0) &&
 641       r == 0 && (S_ISREG (finfo.st_mode) == 0) &&
 642       same_file (filename, filename, &finfo, &finfo2))
 643     return fd;
 644
 645   /* The file has been replaced.  badness. */
 646   close (fd);
 647   errno = EEXIST;
 648   return (NOCLOBBER_REDIRECT);