Fix for semaphore access by child.
* configure.ac (HAVE_FORK_UNSAFE_SEMAPHORE): New. * src/npth.c (sem_init): Use NPTH_SEMAPHORE_PSHARED. * tests/t-fork.c: New.
Thanks to Uldis Anšmits.
- GnuPG-bug-id: T2260
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>