From 6954b78398ed30e479f8827d189a9e9265e85aa5 Mon Sep 17 00:00:00 2001
From: sungdark <sungdark@users.noreply.github.com>
Date: Sat, 28 Mar 2026 08:27:01 +0000
Subject: [PATCH] fix: use char-aware truncation to prevent UTF-8 panics

Fixes 3 byte-boundary panics in agent_cmd handlers when agent
descriptions/prompts contain multi-byte UTF-8 characters (emojis,
international text) near truncation boundaries.

- list.rs: use chars().take(35) instead of byte slice [..35]
- show.rs: use chars().take(500) instead of byte slice [..500]
- generate.rs: use chars().take(500) instead of byte slice [..500]

These panics crashed the entire CLI when users had emojis or
non-ASCII characters in their agent descriptions/prompts.
---
 src/cortex-cli/src/agent_cmd/handlers/generate.rs | 6 +++---
 src/cortex-cli/src/agent_cmd/handlers/list.rs     | 4 ++--
 src/cortex-cli/src/agent_cmd/handlers/show.rs     | 6 +++---
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/cortex-cli/src/agent_cmd/handlers/generate.rs b/src/cortex-cli/src/agent_cmd/handlers/generate.rs
index b3bbabd6..af23b9d6 100644
--- a/src/cortex-cli/src/agent_cmd/handlers/generate.rs
+++ b/src/cortex-cli/src/agent_cmd/handlers/generate.rs
@@ -117,11 +117,11 @@ pub async fn run_generate(args: CreateArgs) -> Result<()> {
         println!("  {}", "-".repeat(36));
 
         // Show truncated prompt
-        let prompt_preview = if generated.system_prompt.len() > 500 {
+        let prompt_preview = if generated.system_prompt.chars().count() > 500 {
             format!(
                 "{}...\n\n    (truncated, {} chars total)",
-                &generated.system_prompt[..500],
-                generated.system_prompt.len()
+                generated.system_prompt.chars().take(500).collect::<String>(),
+                generated.system_prompt.chars().count()
             )
         } else {
             generated.system_prompt.clone()
diff --git a/src/cortex-cli/src/agent_cmd/handlers/list.rs b/src/cortex-cli/src/agent_cmd/handlers/list.rs
index d81f25d9..9bf79702 100644
--- a/src/cortex-cli/src/agent_cmd/handlers/list.rs
+++ b/src/cortex-cli/src/agent_cmd/handlers/list.rs
@@ -91,8 +91,8 @@ pub async fn run_list(args: ListArgs) -> Result<()> {
             .description
             .as_ref()
             .map(|d| {
-                if d.len() > 38 {
-                    format!("{}...", &d[..35])
+                if d.chars().count() > 38 {
+                    format!("{}...", d.chars().take(35).collect::<String>())
                 } else {
                     d.clone()
                 }
diff --git a/src/cortex-cli/src/agent_cmd/handlers/show.rs b/src/cortex-cli/src/agent_cmd/handlers/show.rs
index e77c2549..d572a894 100644
--- a/src/cortex-cli/src/agent_cmd/handlers/show.rs
+++ b/src/cortex-cli/src/agent_cmd/handlers/show.rs
@@ -136,11 +136,11 @@ pub async fn run_show(args: ShowArgs) -> Result<()> {
     if let Some(ref prompt) = agent.prompt {
         println!("\nSystem Prompt:");
         println!("{}", "-".repeat(40));
-        let preview = if prompt.len() > 500 {
+        let preview = if prompt.chars().count() > 500 {
             format!(
                 "{}...\n\n(truncated, {} chars total)",
-                &prompt[..500],
-                prompt.len()
+                prompt.chars().take(500).collect::<String>(),
+                prompt.chars().count()
             )
         } else {
             prompt.clone()