kmx git

open, openat: handle O_DIRECTORY on special files

On deficient platforms where we must check for directories
ourselves when opening files, check before opening as well as after.
This prevents a hang when trying to open a special file like a
fifo in a context where a directory is required.  Although there
is still a race so we could still hang in a perverse situation,
it’s the best we can do and it is better than hanging in the
more-common case.
* lib/open.c (lstatif): New static function.
(open) [REPLACE_FCHDIR]: Also inspect O_CREAT.
* lib/open.c (open), lib/openat.c (rpl_openat):
When checking for directories, also do this before opening.
Also, respect O_NOFOLLOW when checking for directories.
* lib/openat.c: Remove a few more unnecessary differences from open.c.
* modules/open (Depends-on): Depend on lstat.
* modules/openat (Depends-on): Add fstatat.
* modules/open-tests, modules/openat-tests:
(configure.ac) Check for alarm decl.
* tests/test-open.c, tests/test-openat.c:
Include sys/stat.h, for mkfifo.
[HAVE_DECL_ALARM]: Include signal.h, for alarm.
* tests/test-open.h (test_open): Fail if test takes too long
because we tried to open a fifo.  Test opening /dev/null,
/dev/tty and a fifo, with a trailing "/" and with O_DIRECTORY.
kc3-lang/gnulib/modules/openat-tests

Commit

modules/openat-tests
