POSIX and ISC 2.2.x -- how many people are using this?

[Van Gale]

In an article (Heiko Blume) shows an example of posix job control:
>    sigset_t oldmask, newmask;
>    sigemptyset(&oldmask);		/* must initialize */
>    sigemptyset(&newmask);
>    sigaddset(&newmask, SIGCHOKE);	/* add signal to set */
>    sigprocmask(SIG_BLOCK, &newmask, &oldmask);

I haven't been able to read the standard but I assumed (from looking
at a sigprocmask man page) that it wasn't *really* necessary to
initialize oldmask with a call to sigemptyset since sigprocmask is
supposed to return the original mask there.

Does the standard issue a good reason for doing this anyway?

----
Van Gale
van at ocsmd.ocs.com