fix(gl): truncate node-supplied display strings at a char boundary (#350)

crates/gl/src/agent.rs

@@ -89,7 +89,7 @@ async fn cmd_list(node: String, capability: Option<String>) -> Result<()> {
         let short = did
             .split(':')
             .next_back()
-            .map(|s| &s[..s.len().min(16)])
+            .map(|s| crate::text::truncate(s, 16))
             .unwrap_or("?");
         let trust = agent["trust_score"].as_f64().unwrap_or(0.0);
         let caps = agent["capabilities"]

crates/gl/src/bounty.rs

@@ -247,7 +247,7 @@ async fn cmd_list(
                 let title = b["title"].as_str().unwrap_or("?");
                 let amount = b["amount"].as_i64().unwrap_or(0);
                 let st = b["status"].as_str().unwrap_or("?");
-                let short_id = &id[..8.min(id.len())];
+                let short_id = crate::text::truncate(id, 8);
                 println!("{short_id}  {st:<10}  {amount:>12} $GITLAWB  {title}");
             }
         }

crates/gl/src/cert.rs

@@ -120,7 +120,10 @@ async fn cmd_list(repo: String, node: String, dir: Option<PathBuf>) -> Result<()
         let id = cert["id"].as_str().unwrap_or("?");
         let ref_name = cert["ref_name"].as_str().unwrap_or("?");
         let new_sha = cert["new_sha"].as_str().unwrap_or("?");
-        let issued_at = cert["issued_at"].as_str().map(|s| &s[..19]).unwrap_or("?");
+        let issued_at = cert["issued_at"]
+            .as_str()
+            .map(|s| crate::text::truncate(s, 19))
+            .unwrap_or("?");
         println!("  {id:.8}  {issued_at}  {ref_name}  {new_sha:.12}");
     }
     Ok(())

crates/gl/src/changelog.rs

@@ -83,14 +83,14 @@ pub async fn run(args: ChangelogArgs) -> Result<()> {
 
     for event in &events {
         let ts = event["timestamp"].as_str().unwrap_or("?");
-        let date = &ts[..ts.len().min(10)];
+        let date = crate::text::truncate(ts, 10);
 
         match event["type"].as_str().unwrap_or("") {
             "commit" => {
                 let sha = event["sha"].as_str().unwrap_or("?");
                 let msg = event["message"].as_str().unwrap_or("?");
                 let first_line = msg.lines().next().unwrap_or(msg);
-                let short_sha = &sha[..sha.len().min(8)];
+                let short_sha = crate::text::truncate(sha, 8);
                 println!("  {date}  commit      {short_sha}  {first_line}");
             }
             "pr_merged" => {

crates/gl/src/ipfs_cmd.rs

@@ -123,11 +123,7 @@ async fn cmd_list(node: String, dir: Option<PathBuf>) -> Result<()> {
         let sha = pin["sha256_hex"].as_str().unwrap_or("?");
         let pinned_at = pin["pinned_at"].as_str().unwrap_or("?");
         // Trim pinned_at to date+time without subseconds
-        let ts = if pinned_at.len() >= 19 {
-            &pinned_at[..19]
-        } else {
-            pinned_at
-        };
+        let ts = crate::text::truncate(pinned_at, 19);
         println!("  {cid}");
         println!("    sha256: {sha}");
         println!("    pinned: {ts}");

crates/gl/src/issue.rs

@@ -243,7 +243,7 @@ async fn cmd_list(repo: String, node: String, dir: Option<PathBuf>) -> Result<()
         let status = issue["status"].as_str().unwrap_or("?");
         let created = issue["created_at"]
             .as_str()
-            .map(|s| &s[..10])
+            .map(|s| crate::text::truncate(s, 10))
             .unwrap_or("?");
         let icon = match status {
             "open" => "○",
@@ -374,10 +374,13 @@ async fn cmd_issue_comments(
         let author_short = author
             .split(':')
             .next_back()
-            .map(|s| &s[..s.len().min(8)])
+            .map(|s| crate::text::truncate(s, 8))
             .unwrap_or("?");
         let cbody = c["body"].as_str().unwrap_or("");
-        let created = c["created_at"].as_str().map(|s| &s[..10]).unwrap_or("?");
+        let created = c["created_at"]
+            .as_str()
+            .map(|s| crate::text::truncate(s, 10))
+            .unwrap_or("?");
         println!("  · {author_short} ({created})");
         println!("    {cbody}");
         println!();
@@ -448,6 +451,34 @@ mod tests {
         .unwrap();
     }
 
+    #[tokio::test]
+    async fn test_cmd_list_survives_malformed_timestamps() {
+        let dir = TempDir::new().unwrap();
+        write_identity(&dir);
+
+        let mut server = mockito::Server::new_async().await;
+        // A short timestamp used to panic on `&s[..10]`; a timestamp whose
+        // byte 10 is mid-char panics even with a len() guard.
+        let _m = server
+            .mock(
+                "GET",
+                mockito::Matcher::Regex(r"^/api/v1/repos/[^/]+/myrepo/issues$".to_string()),
+            )
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .with_body(r#"{"issues":[{"id":"a","title":"short ts","status":"open","created_at":"2026"},{"id":"b","title":"mb ts","status":"open","created_at":"2026-08-1é5T00:00:00Z"},{"id":"c","title":"empty ts","status":"open","created_at":""}]}"#)
+            .create_async()
+            .await;
+
+        cmd_list(
+            "myrepo".to_string(),
+            server.url(),
+            Some(dir.path().to_path_buf()),
+        )
+        .await
+        .unwrap();
+    }
+
     #[tokio::test]
     async fn test_cmd_create_success() {
         let dir = TempDir::new().unwrap();

crates/gl/src/main.rs

@@ -30,6 +30,7 @@ mod star;
 mod status;
 mod sync;
 mod task;
+mod text;
 mod ucan_cmd;
 mod visibility;
 mod webhook;

crates/gl/src/node.rs

@@ -401,7 +401,7 @@ async fn cmd_status(node: String, dir: Option<PathBuf>) -> Result<()> {
                     let ref_name = ev["ref"].as_str().unwrap_or("?");
                     let ts = ev["timestamp"]
                         .as_str()
-                        .map(|s| &s[..10.min(s.len())])
+                        .map(|s| crate::text::truncate(s, 10))
                         .unwrap_or("?");
                     println!("  {ts}  {repo}  {ref_name}");
                 }

crates/gl/src/peer.rs

@@ -86,7 +86,7 @@ async fn cmd_list(node: String) -> Result<()> {
         let reachable = peer["reachable"].as_bool().unwrap_or(false);
         let last_seen = peer["last_seen"]
             .as_str()
-            .map(|s| &s[..10])
+            .map(|s| crate::text::truncate(s, 10))
             .unwrap_or("never");
         let status = if reachable { "✓" } else { "✗" };
         println!("  {status} {url}");

crates/gl/src/pr.rs

@@ -278,7 +278,7 @@ async fn cmd_list(repo: String, node: String, dir: Option<PathBuf>) -> Result<()
         let author_short = author
             .split(':')
             .next_back()
-            .map(|s| &s[..s.len().min(8)])
+            .map(|s| crate::text::truncate(s, 8))
             .unwrap_or("?");
         let status_icon = match status {
             "open" => "○",
@@ -337,7 +337,7 @@ async fn cmd_view(repo: String, number: u64, node: String, dir: Option<PathBuf>)
             let reviewer_short = reviewer
                 .split(':')
                 .next_back()
-                .map(|s| &s[..s.len().min(8)])
+                .map(|s| crate::text::truncate(s, 8))
                 .unwrap_or("?");
             let rstatus = r["status"].as_str().unwrap_or("?");
             let rbody = r["body"].as_str().unwrap_or("");
@@ -370,10 +370,13 @@ async fn cmd_view(repo: String, number: u64, node: String, dir: Option<PathBuf>)
             let author_short = author
                 .split(':')
                 .next_back()
-                .map(|s| &s[..s.len().min(8)])
+                .map(|s| crate::text::truncate(s, 8))
                 .unwrap_or("?");
             let cbody = c["body"].as_str().unwrap_or("");
-            let created = c["created_at"].as_str().map(|s| &s[..10]).unwrap_or("?");
+            let created = c["created_at"]
+                .as_str()
+                .map(|s| crate::text::truncate(s, 10))
+                .unwrap_or("?");
             println!("  · {author_short} ({created})");
             println!("    {cbody}");
         }
@@ -425,7 +428,7 @@ async fn cmd_merge(repo: String, number: u64, node: String, dir: Option<PathBuf>
 
     let sha = result["merge_sha"].as_str().unwrap_or("?");
     println!("✓ Merged PR #{number}");
-    println!("  Merge commit: {}", &sha[..sha.len().min(12)]);
+    println!("  Merge commit: {}", crate::text::truncate(sha, 12));
     Ok(())
 }
 
@@ -527,10 +530,13 @@ async fn cmd_comments(repo: String, number: u64, node: String, dir: Option<PathB
         let author_short = author
             .split(':')
             .next_back()
-            .map(|s| &s[..s.len().min(8)])
+            .map(|s| crate::text::truncate(s, 8))
             .unwrap_or("?");
         let cbody = c["body"].as_str().unwrap_or("");
-        let created = c["created_at"].as_str().map(|s| &s[..10]).unwrap_or("?");
+        let created = c["created_at"]
+            .as_str()
+            .map(|s| crate::text::truncate(s, 10))
+            .unwrap_or("?");
         println!("  · {author_short} ({created})");
         println!("    {cbody}");
         println!();

crates/gl/src/repo.rs

@@ -296,7 +296,10 @@ async fn cmd_list(node: String, dir: Option<PathBuf>) -> Result<()> {
         let name = r["name"].as_str().unwrap_or("?");
         let desc = r["description"].as_str().unwrap_or("");
         let public = r["is_public"].as_bool().unwrap_or(true);
-        let updated = r["updated_at"].as_str().map(|s| &s[..10]).unwrap_or("?");
+        let updated = r["updated_at"]
+            .as_str()
+            .map(|s| crate::text::truncate(s, 10))
+            .unwrap_or("?");
         let vis = if public { "public" } else { "private" };
         println!("  {name:<24}  {vis:<8}  {updated}  {desc}");
     }
@@ -495,7 +498,7 @@ async fn cmd_replicas(repo: String, node: String, dir: Option<PathBuf>) -> Resul
             let url = r["replica_url"].as_str().unwrap_or("?");
             let registered = r["registered_at"]
                 .as_str()
-                .map(|s| &s[..10.min(s.len())])
+                .map(|s| crate::text::truncate(s, 10))
                 .unwrap_or("?");
             println!("  {registered}  {did}  →  {url}");
         }
@@ -542,7 +545,7 @@ pub(crate) async fn cmd_commits(
             .or_else(|| c["sha"].as_str())
             .or_else(|| c["oid"].as_str())
             .unwrap_or("?");
-        let short_sha = &sha[..sha.len().min(10)];
+        let short_sha = crate::text::truncate(sha, 10);
         let msg = c["message"].as_str().unwrap_or("(no message)");
         let first_line = msg.lines().next().unwrap_or(msg);
         let author = c["author_name"]
@@ -552,7 +555,7 @@ pub(crate) async fn cmd_commits(
         let date = c["date"]
             .as_str()
             .or_else(|| c["committer_date"].as_str())
-            .map(|s| &s[..10.min(s.len())])
+            .map(|s| crate::text::truncate(s, 10))
             .unwrap_or("?");
         println!("  {short_sha}  {date}  {first_line}  ({author})");
     }

crates/gl/src/text.rs

@@ -0,0 +1,39 @@
+//! Display helpers for strings that come off the wire unchecked.
+
+/// Truncate `s` to at most `max` bytes, cutting at a char boundary.
+///
+/// `&s[..max]` panics when `s` is shorter than `max` bytes and when `max`
+/// lands inside a multi-byte char; `s.len().min(max)` guards only the first
+/// case. Node-supplied timestamps and ids hit both.
+pub(crate) fn truncate(s: &str, max: usize) -> &str {
+    let mut end = max.min(s.len());
+    while !s.is_char_boundary(end) {
+        end -= 1;
+    }
+    &s[..end]
+}
+
+#[cfg(test)]
+mod tests {
+    use super::truncate;
+
+    #[test]
+    fn cuts_ascii_at_max() {
+        assert_eq!(truncate("2026-08-15T12:34:56Z", 10), "2026-08-15");
+    }
+
+    #[test]
+    fn short_and_empty_inputs_return_whole() {
+        assert_eq!(truncate("2026", 10), "2026");
+        assert_eq!(truncate("", 10), "");
+    }
+
+    #[test]
+    fn multibyte_cut_does_not_panic() {
+        // Byte index 10 lands inside 'é'; the cut must land on the boundary
+        // before it (9 bytes) rather than panic or exceed the byte limit.
+        assert_eq!(truncate("2026-08-1\u{e9}5T12:34:56Z", 10), "2026-08-1");
+        // A string that is entirely multi-byte and shorter than max.
+        assert_eq!(truncate("\u{e9}\u{e9}", 10), "\u{e9}\u{e9}");
+    }
+}