Re: PQHost() undefined behavior if connecting string contains bothhost and hostaddr types

On 1/13/18 22:19, Haribabu Kommi wrote:
> While working on [1], we find out the inconsistency in PQHost() behavior
> if the connecting string that is passed to connect to the server contains
> multiple hosts with both host and hostaddr types. For example,
> 
> host=host1,host2 hostaddr=127.0.0.1,127.0.0.1 port=5434,5432
> 
> As the hostaddr is given preference when both host and hostaddr is 
> specified, so the connection type for both addresses of the above
> conninfo is CHT_HOST_ADDRESS. So the PQhost() returns the
> conn->pghost value i.e "host1,host2" instead of the actual host that
> is connected.
> 
> Instead of checking the connection type while returning the host
> details, it should check whether the host is NULL or not? with this
> change it returns the expected value for all the connection types.

I agree that something is wrong here.

It seems, however, that PGhost() has always been broken for hostaddr
use.  In 9.6 (before the multiple-hosts stuff was introduced), when
connecting to "hostaddr=127.0.0.1", PGhost() returns "/tmp".  Urgh.

I think we should decide what PGhost() is supposed to mean when hostaddr
is in use, and then make a fix for that consistently across all versions.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services