The problems of PQhost()

Hi,

I reported in other thread that PQhost() has three problems.

http://www.postgresql.org/message-id/CAHGQGwE77AKyabYwde5+8BjLdOpThp7cnswaO_syEdJOGYvnNw@mail.gmail.com
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(1) PQhost() can return Unix-domain socket directory path even in the
platform that
    doesn't support Unix-domain socket.

(2) In the platform that doesn't support Unix-domain socket, when
neither host nor hostaddr
    are specified, the default host 'localhost' is used to connect to
the server and
    PQhost() must return that, but it doesn't.

(3) PQhost() cannot return the hostaddr.

As the result of these problems, you can see the incorrect result of
\conninfo, for example.

$ psql -d "hostaddr=127.0.0.1"
=# \conninfo
You are connected to database "postgres" as user "postgres" via socket
in "/tmp" at port "5432".

Obviously "/tmp" should be "127.0.0.1".
------------------------

Attached patch fixes these problems.

We can fix the problem (3) by changing PQhost() so that it also
returns the hostaddr. But this change might break the existing
application using PQhost(). So, I added new libpq function PQhostaddr()
which returns the hostaddr, and changed \conninfo so that it reports
correct connection information by using both PQhost() and PQhostaddr().

These problems exist in v9.3 or before. Basically we should backport
the patch into those versions. But obviously it's too late to add new libpq
function PQhostaddr() into those versions. Then, I'm thinking to backport
only the change for (1) and (2) because we can fix them without adding
new libpq function.

BTW, I think that the patch also fixes the problem of \conninfo that
MauMau reported in other thread.
http://www.postgresql.org/message-id/8913B51B3B534F878D54B89E1EB964C6@maumau

Regards,

--
Fujii Masao