From f464e30feef1f80a65b2c9dfc9fad5246ed69237 Mon Sep 17 00:00:00 2001
From: Jim Kalafut <jim@kalafut.net>
Date: Fri, 5 Oct 2018 16:05:26 -0700
Subject: [PATCH] Fix 'vault auth' panic (#5473)

Running 'vault auth' with no parameters was panicking:

panic: assignment to entry in nil map
	github.com/hashicorp/vault/command/login.go:255 +0xdee

Now it will show help.
---
 command/auth.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/command/auth.go b/command/auth.go
index d51c067b1076..78daf6d53d97 100644
--- a/command/auth.go
+++ b/command/auth.go
@@ -62,6 +62,10 @@ func (c *AuthCommand) Run(args []string) int {
 	// Deprecation
 	// TODO: remove in 0.9.0
 
+	if len(args) == 0 {
+		return cli.RunResultHelp
+	}
+
 	// Parse the args for our deprecations and defer to the proper areas.
 	for _, arg := range args {
 		switch {