From 953e08df992fac463cfd5bd8794d01cadb5d25fe Mon Sep 17 00:00:00 2001
From: Kelsey Francis <kelseyfrancis@gmail.com>
Date: Fri, 8 Sep 2017 15:49:54 -0700
Subject: [PATCH] Prefix types in namespaces other than pg_catalog or public

It's possible to define a type (e.g., an enum) with the same name in two
different schemas. When initializing data types after connecting, types
defined within schemas other than pg_catalog or public should be
qualified with their schema name to disambiguate them and ensure all
types with the same base name get added to the map of OID to type.

Prior to this commit, the last type scanned would "win", and all others
with the same name would be missing from the ConnInfo type maps, which
would subsequently cause any PREPARE involving columns of those missing
types to return the error "unknown oid".
---
 conn.go          |  6 +++++-
 conn_test.go     | 28 ++++++++++++++++++++++++++++
 pgmock/pgmock.go | 12 +++++++++++-
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/conn.go b/conn.go
index f549e03e..540ff31f 100644
--- a/conn.go
+++ b/conn.go
@@ -384,9 +384,13 @@ func (c *Conn) connect(config ConnConfig, network, address string, tlsConfig *tl
 func (c *Conn) initConnInfo() error {
 	nameOIDs := make(map[string]pgtype.OID, 256)
 
-	rows, err := c.Query(`select t.oid, t.typname
+	rows, err := c.Query(`select t.oid,
+	case when nsp.nspname in ('pg_catalog', 'public') then t.typname
+		else nsp.nspname||'.'||t.typname
+	end
 from pg_type t
 left join pg_type base_type on t.typelem=base_type.oid
+left join pg_namespace nsp on t.typnamespace=nsp.oid
 where (
 	  t.typtype in('b', 'p', 'r', 'e')
 	  and (base_type.oid is null or base_type.typtype in('b', 'p', 'r'))
diff --git a/conn_test.go b/conn_test.go
index 1996f814..557a86f1 100644
--- a/conn_test.go
+++ b/conn_test.go
@@ -1953,3 +1953,31 @@ end$$;`)
 
 	ensureConnValid(t, conn)
 }
+
+func TestConnInitConnInfo(t *testing.T) {
+	conn := mustConnect(t, *defaultConnConfig)
+	defer closeConn(t, conn)
+
+	// spot check that the standard postgres type names aren't qualified
+	nameOIDs := map[string]pgtype.OID{
+		"_int8": pgtype.Int8ArrayOID,
+		"int8": pgtype.Int8OID,
+		"json": pgtype.JSONOID,
+		"text": pgtype.TextOID,
+	}
+	for name, oid := range nameOIDs {
+		dtByName, ok := conn.ConnInfo.DataTypeForName(name)
+		if !ok {
+			t.Fatalf("Expected type named %v to be present", name)
+		}
+		dtByOID, ok := conn.ConnInfo.DataTypeForOID(oid)
+		if !ok {
+			t.Fatalf("Expected type OID %v to be present", oid)
+		}
+		if dtByName != dtByOID {
+			t.Fatalf("Expected type named %v to be the same as type OID %v", name, oid)
+		}
+	}
+
+	ensureConnValid(t, conn)
+}
diff --git a/pgmock/pgmock.go b/pgmock/pgmock.go
index fe78b009..e65a25fb 100644
--- a/pgmock/pgmock.go
+++ b/pgmock/pgmock.go
@@ -204,7 +204,17 @@ func AcceptUnauthenticatedConnRequestSteps() []Step {
 func PgxInitSteps() []Step {
 	steps := []Step{
 		ExpectMessage(&pgproto3.Parse{
-			Query: "select t.oid, t.typname\nfrom pg_type t\nleft join pg_type base_type on t.typelem=base_type.oid\nwhere (\n\t  t.typtype in('b', 'p', 'r', 'e')\n\t  and (base_type.oid is null or base_type.typtype in('b', 'p', 'r'))\n\t)",
+			Query: `select t.oid,
+	case when nsp.nspname in ('pg_catalog', 'public') then t.typname
+		else nsp.nspname||'.'||t.typname
+	end
+from pg_type t
+left join pg_type base_type on t.typelem=base_type.oid
+left join pg_namespace nsp on t.typnamespace=nsp.oid
+where (
+	  t.typtype in('b', 'p', 'r', 'e')
+	  and (base_type.oid is null or base_type.typtype in('b', 'p', 'r'))
+	)`,
 		}),
 		ExpectMessage(&pgproto3.Describe{
 			ObjectType: 'S',