Change libpq's internal uses of PQhost() to inspect host field directly.

Commit 1944cdc98 changed PQhost() to return the hostaddr value when that
is specified and host isn't.  This is a good idea in general, but
fe-auth.c and related files contain PQhost() calls for which it isn't.
Specifically, when we compare SSL certificates or other server identity
information to the host field, we do not want to use hostaddr instead;
that's not what's documented, that's not what happened pre-v10, and
it doesn't seem like a good idea.

Instead, we can just look at connhost[].host directly.  This does what
we want in v10 and up; in particular, if neither host nor hostaddr
were given, the host field will be replaced with the default host name.
That seems useful, and it's likely the reason that these places were
coded to call PQhost() originally (since pre-v10, the stored field was
not replaced with the default).

Back-patch to v10, as 1944cdc98 (just) was.

Discussion: https://postgr.es/m/[email protected]

1 files changed, 2 insertions, 2 deletions

diff --git a/src/interfaces/libpq/fe-auth.c b/src/interfaces/libpq/fe-auth.c
index 3b2073a47fe..09012c562d0 100644
--- a/src/interfaces/libpq/fe-auth.c
+++ b/src/interfaces/libpq/fe-auth.c
@@ -199,7 +199,7 @@ pg_GSS_startup(PGconn *conn, int payloadlen)
 				min_stat;
 	int			maxlen;
 	gss_buffer_desc temp_gbuf;
-	char	   *host = PQhost(conn);
+	char	   *host = conn->connhost[conn->whichhost].host;
 
 	if (!(host && host[0] != '\0'))
 	{
@@ -414,7 +414,7 @@ pg_SSPI_startup(PGconn *conn, int use_negotiate, int payloadlen)
 {
 	SECURITY_STATUS r;
 	TimeStamp	expire;
-	char	   *host = PQhost(conn);
+	char	   *host = conn->connhost[conn->whichhost].host;
 
 	if (conn->sspictx)
 	{