This fixes a race condition where another thread may fork() before CLOEXEC
is set, unintentionally passing the descriptor to the child process.
This commit only adds O_CLOEXEC flags to open() or openat() calls where no
fcntl(fd, F_SETFD, FD_CLOEXEC) follows. The separate fcntl() call still
leaves a race window so it should be fixed later.
implementation did not match our manpage description (i.e., it could
return NULL). I mistakenly thought we were still using getpass.c
because, for some reason, CVS never removed it from the tree.
Pointy hat received from: alfred
Kick in the groin to: CVS
