pthread_mutexattr_settype non-conformance to man-page and POSIX

[Heiko Wundram]

I hit a bug in libthr with pthread_mutexattr_settype which (at least as far as 
I understand the POSIX reference and also the man-page) makes it 
non-conformant to the specifications.

Quoting:

"""
RETURN VALUES
     If successful, these functions return 0.  Otherwise, an error number is
     returned to indicate the error.
...
ERRORS
...
     The pthread_mutexattr_settype() function will fail if:

     [EINVAL]           Invalid value for attr, or invalid value for type.
"""

This does not happen (at least not in libthr):

"""
int
_pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type)
{
        int     ret;
        if (attr == NULL || *attr == NULL || type >= PTHREAD_MUTEX_TYPE_MAX) {
                errno = EINVAL;
                ret = -1;
        } else {
                (*attr)->m_type = type;
                ret = 0;
        }
        return(ret);
}
"""

The error code EINVAL is stored to errno, and -1 is returned, which is wrong 
at least according to my understanding of the man-page, which pretty much 
says the same thing as POSIX.

I haven't looked yet whether this code has always been this way for FreeBSD, 
but at least under glibc[+NPTL], the error-number is returned directly as the 
return value (from a quick skimming of the sources), just as I would 
understand the specifications.

The code in question is similar to pretty much all other functions in libthr, 
which also set errno and return -1, so basically it's a systematic error in 
the implementation of libthr, if I'm not completely mistaken.

Anybody else have any more insight on this?

-- 
Heiko Wundram