BUG #6657: Documentation bug for PQconnectdbParams

The following bug has been logged on the website:

Bug reference:      6657
Logged by:          Eric Diven
Email address:      ediven@edsiohio.com
PostgreSQL version: 9.0.2
Operating system:   Solaris
Description:=20=20=20=20=20=20=20=20

First off, I should thank you all for the generally excellent documentation.
 The plpgsql documentation has been particularly helpful, in large part
thanks to the relevant and well-explained examples.

That said, I would humbly suggest that the documentation for the
PQconnectdbParams function omits certain details.  Notably, the function
will return NULL if you pass in a keywords array with an unrecognized
keyword.

I'll be the first to admit that passing in a keyword of "host_addr" instead
of "hostaddr" was kind of a dumb mistake on my part, but I'd argue that I'd
have figured it out a lot sooner if this were the documented behavior of
PQconnectdbParams for this case.

I realize I'm submitting this against an out of date version of postgresql,
and the the behavior might have changed since then, but since the
documentation covers all of 9.0.x, I would say that it still bears
updating.

Thanks,

Eric Diven

Example code follows:

#include <libpq-fe.h>

int main (int argc, char *argv[])
{
    PGconn *conn =3D NULL;
    char *keys[] =3D { "host_addr", "user", "password", NULL };
    char *values[] =3D { "192.168.0.42", "user", "password", NULL };

    conn =3D PQconnectdbParams (keys, values, 0);

    printf ("%p\n", conn);
    return 0;
}