From bdd8ce66920b4aaded3b08b46fa5890d9ba192ca Mon Sep 17 00:00:00 2001
From: shayne <shayne@tailscale.com>
Date: Sun, 20 Nov 2022 15:04:58 -0500
Subject: [PATCH] cmd/tailscale/cli: disallow empty text "" from serve CLI
 (#6416)

Current behavior is broken. tailscale serve text / "" returns no error
and shows up in tailscale serve status but requests return a 500
"empty handler".

Adds an error if the user passes in an empty string for the text
handler.

Closes #6405

Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
---
 cmd/tailscale/cli/serve.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/cmd/tailscale/cli/serve.go b/cmd/tailscale/cli/serve.go
index 402b64da5..4987064b7 100644
--- a/cmd/tailscale/cli/serve.go
+++ b/cmd/tailscale/cli/serve.go
@@ -285,6 +285,9 @@ func (e *serveEnv) runServe(ctx context.Context, args []string) error {
 		}
 		h.Proxy = t
 	case "text":
+		if args[2] == "" {
+			return errors.New("unable to serve; text cannot be an empty string")
+		}
 		h.Text = args[2]
 	default:
 		fmt.Fprintf(os.Stderr, "error: unknown serve type %q\n\n", args[1])