From d4f70397930b15c8860a71df1abb9bc5ac9ab4ff Mon Sep 17 00:00:00 2001
From: David Calavera <david.calavera@gmail.com>
Date: Sat, 27 Jul 2013 10:00:36 -0700
Subject: [PATCH] Do not show empty parenthesis if the default configuration is
 missing.

---
 commands.go | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/commands.go b/commands.go
index 0fabaa385f..a7df369e5f 100644
--- a/commands.go
+++ b/commands.go
@@ -314,13 +314,21 @@ func (cli *DockerCli) CmdLogin(args ...string) error {
 		email    string
 	)
 
+	var promptDefault = func(stdout io.Writer, prompt string, configDefault string) {
+		if configDefault == "" {
+			fmt.Fprintf(cli.out, "%s: ", prompt)
+		} else {
+			fmt.Fprintf(cli.out, "%s (%s): ", prompt, configDefault)
+		}
+	}
+
 	authconfig, ok := cli.configFile.Configs[auth.IndexServerAddress()]
 	if !ok {
 		authconfig = auth.AuthConfig{}
 	}
 
 	if *flUsername == "" {
-		fmt.Fprintf(cli.out, "Username (%s): ", authconfig.Username)
+		promptDefault(cli.out, "Username", authconfig.Username)
 		username = readAndEchoString(cli.in, cli.out)
 		if username == "" {
 			username = authconfig.Username
@@ -340,7 +348,7 @@ func (cli *DockerCli) CmdLogin(args ...string) error {
 		}
 
 		if *flEmail == "" {
-			fmt.Fprintf(cli.out, "Email (%s): ", authconfig.Email)
+			promptDefault(cli.out, "Email", authconfig.Email)
 			email = readAndEchoString(cli.in, cli.out)
 			if email == "" {
 				email = authconfig.Email