From cfee151d4e03aea6e133e0ec2b4658ac3275d283 Mon Sep 17 00:00:00 2001
From: ammkrn <46387933+ammkrn@users.noreply.github.com>
Date: Mon, 3 May 2021 22:50:38 -0500
Subject: [PATCH] Dont unwrap rustyline helper in cli (#3382)

If nu fails to load a user config on startup, no helper is set and the
later call to `rl.helper_mut()` will panic. There may be better ways to
handle this long-term, but printing an error about the failure to parse
the config and then starting with default values seems reasonable.
---
 crates/nu-cli/src/cli.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/crates/nu-cli/src/cli.rs b/crates/nu-cli/src/cli.rs
index 698411776..30eb066be 100644
--- a/crates/nu-cli/src/cli.rs
+++ b/crates/nu-cli/src/cli.rs
@@ -301,7 +301,9 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
             }
         };
 
-        rl.helper_mut().expect("No helper").colored_prompt = colored_prompt;
+        if let Some(helper) = rl.helper_mut() {
+            helper.colored_prompt = colored_prompt;
+        }
         let mut initial_command = Some(String::new());
         let mut readline = Err(ReadlineError::Eof);
         while let Some(ref cmd) = initial_command {