Changing SendBytesWithResults to ReceiveResults (that only does the reading).

pgconn.go

@@ -904,14 +904,12 @@ func (pgConn *PgConn) Exec(ctx context.Context, sql string) *MultiResultReader {
 	return multiResult
 }
 
-// SendBytesWithResults sends buf to the PostgreSQL server. It must only be used when the connection is not busy. e.g. It is as
+// ReceiveResults reads the result that might be returned by Postgres after a SendBytes
-// error to call SendBytes while reading the result of a query.
+// (e.a. after sending a CopyDone in a copy-both situation).
 //
 // This is a very low level method that requires deep understanding of the PostgreSQL wire protocol to use correctly.
 // See https://www.postgresql.org/docs/current/protocol.html.
-//
+func (pgConn *PgConn) ReceiveResults(ctx context.Context) *MultiResultReader {
-// So far this only seems required with CopyDone handling.
-func (pgConn *PgConn) SendBytesWithResults(ctx context.Context, buf []byte) *MultiResultReader {
 	if err := pgConn.lock(); err != nil {
 		return &MultiResultReader{
 			closed: true,
@@ -936,16 +934,6 @@ func (pgConn *PgConn) SendBytesWithResults(ctx context.Context, buf []byte) *Mul
 		pgConn.contextWatcher.Watch(ctx)
 	}
 
-	n, err := pgConn.conn.Write(buf)
-	if err != nil {
-		pgConn.asyncClose()
-		pgConn.contextWatcher.Unwatch()
-		multiResult.closed = true
-		multiResult.err = &writeError{err: err, safeToRetry: n == 0}
-		pgConn.unlock()
-		return multiResult
-	}
-
 	return multiResult
 }