Hey Robert,
I've asked pgsql-general.
Unfortunately it seems that there is no better way to do it except
parsing PQerrorMessage(). Sadly.
2010/10/17 Robert Haas <robertmhaas(at)gmail(dot)com>
> On Thu, Oct 14, 2010 at 2:59 PM, Dmitriy Igrishin <dmitigr(at)gmail(dot)com>
> wrote:
> > Is there way to determine failed connection attempt due to invalid
> > authorization (libpq)?
>
> I think this question would be more appropriate on pgsql-general. I
> suppose you would have to look at PQerrorMessage().
>
> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>
--
// Dmitriy.