net/smtp: match actual behavior for Auth.Start

Looking at history, it appears to never have worked as documented.

Fixes #48759

Change-Id: I066307c28e3ed1875c1c4049bade62e2818dd400
Reviewed-on: https://go-review.googlesource.com/c/go/+/383998
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Cherry Mui <cherryyz@google.com>

diff --git a/src/net/smtp/auth.go b/src/net/smtp/auth.go
index fd1a472f930dd48203ee5459682e12ba9e580018..7a32ef6a2e615b4cb7b88b04aced247e3993b26b 100644 (file)
--- a/src/net/smtp/auth.go
+++ b/src/net/smtp/auth.go
@@ -16,8 +16,7 @@ type Auth interface {
        // Start begins an authentication with a server.
        // It returns the name of the authentication protocol
        // and optionally data to include in the initial AUTH message
-       // sent to the server. It can return proto == "" to indicate
-       // that the authentication should be skipped.
+       // sent to the server.
        // If it returns a non-nil error, the SMTP client aborts
        // the authentication attempt and closes the connection.
        Start(server *ServerInfo) (proto string, toServer []byte, err error)