Treat unknown oid's as text type

connection.go

@@ -352,7 +352,7 @@ func (c *Connection) sendPreparedQuery(ps *PreparedStatement, arguments ...inter
 	for _, oid := range ps.ParameterOids {
 		transcoder := valueTranscoders[oid]
 		if transcoder == nil {
-			panic(fmt.Sprintf("can't encode %#v", oid))
+			transcoder = defaultTranscoder
 		}
 		binary.Write(buf, binary.BigEndian, transcoder.EncodeFormat)
 	}
@@ -360,6 +360,9 @@ func (c *Connection) sendPreparedQuery(ps *PreparedStatement, arguments ...inter
 	binary.Write(buf, binary.BigEndian, int16(len(arguments)))
 	for i, oid := range ps.ParameterOids {
 		transcoder := valueTranscoders[oid]
+		if transcoder == nil {
+			transcoder = defaultTranscoder
+		}
 		transcoder.EncodeTo(buf, arguments[i])
 	}
 	binary.Write(buf, binary.BigEndian, int16(0))

connection_test.go

@@ -326,6 +326,9 @@ func TestPrepare(t *testing.T) {
 	testTranscode("select $1::float8", float64(1.23))
 	testTranscode("select $1::boolean", true)
 
+	// Ensure that unknown types are just treated as strings
+	testTranscode("select $1::point", "(0,0)")
+
 	// case []byte:
 	// 	s = `E'\\x` + hex.EncodeToString(arg) + `'`
 

value_transcoder.go

@@ -15,6 +15,7 @@ type valueTranscoder struct {
 }
 
 var valueTranscoders map[oid]*valueTranscoder
+var defaultTranscoder *valueTranscoder
 
 func init() {
 	valueTranscoders = make(map[oid]*valueTranscoder)
@@ -56,6 +57,9 @@ func init() {
 
 	// varchar -- same as text
 	valueTranscoders[oid(1043)] = valueTranscoders[oid(25)]
+
+	// use text transcoder for anything we don't understand
+	defaultTranscoder = valueTranscoders[oid(25)]
 }
 
 func decodeBoolFromText(mr *MessageReader, size int32) interface{} {