base red: panic ratchet: cmux-rd-link's 7, acpmux's and cmux-tui's new index/slice hits

cmux-tui/crates/acpmux/src/cli/host_peering.rs

@@ -202,16 +202,17 @@ pub(crate) async fn peer_step(
     let settle = |reply: Result<Value>| match reply {
         Err(e) => fail(format!("the local daemon refused {name} at {url}: {e}")),
         // The peer stopped (it was removed, or never started) before its attempt settled.
-        Ok(reply) if reply["wait"]["stopped"] == true => fail(format!(
+        Ok(reply) if reply.pointer("/wait/stopped") == Some(&Value::Bool(true)) => fail(format!(
             "{name} at {url} stopped before it connected{}",
-            last_error(&reply["wait"]["peer"])
+            last_error(reply.pointer("/wait/peer").unwrap_or(&Value::Null))
         ))
         .with_fix("`acpmux host ls` shows whether it is still configured; add it again if not."),
         // The daemon's wait ran out before the attempt settled (`Hub::wait_for_peer`): say how
         // far it got, not "does not connect" with no reason.
-        Ok(reply) if reply["wait"]["settled"] == false => {
-            let p = &reply["wait"]["peer"];
-            let step = if p["handshaking"] == true { "in its handshake" } else { "connecting" };
+        Ok(reply) if reply.pointer("/wait/settled") == Some(&Value::Bool(false)) => {
+            let p = reply.pointer("/wait/peer").unwrap_or(&Value::Null);
+            let handshaking = p.get("handshaking") == Some(&Value::Bool(true));
+            let step = if handshaking { "in its handshake" } else { "connecting" };
             let secs = reply["wait"]["waitedMs"].as_u64().unwrap_or(0) / 1000;
             fail(format!("{name} at {url} is still {step} after {secs}s{}", last_error(p)))
                 .with_fix("Check again in a minute; `acpmux host ls` shows when it connects.")

cmux-tui/crates/acpmux/src/hub/peers.rs

@@ -235,12 +235,12 @@ impl Hub {
         if stopped {
             tracing::warn!(peer = %name, "it stopped before its connect attempt settled");
         } else if !done {
-            tracing::warn!(peer = %name, state = %peer["state"], "its connect attempt had not settled after {}s; answering with how it is now", budget.as_secs());
+            tracing::warn!(peer = %name, state = %peer.get("state").unwrap_or(&serde_json::Value::Null), "its connect attempt had not settled after {}s; answering with how it is now", budget.as_secs());
         }
         let waited = u64::try_from(started.elapsed().as_millis()).unwrap_or(u64::MAX);
         let mut wait = json!({"settled": done, "waitedMs": waited, "peer": peer});
         if stopped {
-            wait["stopped"] = Value::Bool(true);
+            wait.set("stopped", Value::Bool(true));
         }
         wait
     }

cmux-tui/crates/acpmux/src/server/requests.rs

@@ -63,7 +63,7 @@ pub(super) fn ask<'a>(conn: &Conn, params: &Value, who: &'a str) -> crate::hub::
 /// without one.
 fn with_wait(mut reply: Value, waited: Value) -> Value {
     if !waited.is_null() {
-        reply["wait"] = waited;
+        reply.set("wait", waited);
     }
     reply
 }

cmux-tui/crates/cmux-rd-link/src/lib.rs

@@ -212,7 +212,8 @@ impl Link {
         let n = handshake.write_message(&[], &mut buf).map_err(LinkError::Noise)?;
         let mut packet = Vec::with_capacity(1 + n);
         packet.push(tag);
-        packet.extend_from_slice(&buf[..n]);
+        buf.truncate(n);
+        packet.extend_from_slice(&buf);
         self.out.push_back(packet.clone());
         self.last_handshake = Some((packet, now_us));
         Ok(())
@@ -355,11 +356,12 @@ impl Link {
         let mut plain = Vec::with_capacity(1 + payload.len());
         plain.push(kind);
         plain.extend_from_slice(payload);
-        let mut packet = vec![0u8; 1 + 8 + plain.len() + 16];
-        packet[0] = TAG_SEALED;
-        packet[1..9].copy_from_slice(&nonce.to_le_bytes());
-        let n =
-            transport.write_message(nonce, &plain, &mut packet[9..]).map_err(LinkError::Noise)?;
+        let mut packet = Vec::with_capacity(1 + 8 + plain.len() + 16);
+        packet.push(TAG_SEALED);
+        packet.extend_from_slice(&nonce.to_le_bytes());
+        packet.resize(1 + 8 + plain.len() + 16, 0);
+        let body = packet.get_mut(9..).unwrap_or_default();
+        let n = transport.write_message(nonce, &plain, body).map_err(LinkError::Noise)?;
         packet.truncate(9 + n);
         Ok(packet)
     }

cmux-tui/crates/cmux-rd-link/src/replay.rs

@@ -34,7 +34,7 @@ impl ReplayWindow {
             return false;
         }
         let (word, bit) = Self::slot(nonce);
-        self.bits[word] & bit == 0
+        self.bits.get(word).is_some_and(|w| w & bit == 0)
     }
 
     pub fn accept(&mut self, nonce: u64) {
@@ -43,11 +43,15 @@ impl ReplayWindow {
             let advance = (nonce + 1 - self.top).min(WINDOW);
             for n in 0..advance {
                 let (word, bit) = Self::slot(self.top + n);
-                self.bits[word] &= !bit;
+                if let Some(w) = self.bits.get_mut(word) {
+                    *w &= !bit;
+                }
             }
             self.top = nonce + 1;
         }
         let (word, bit) = Self::slot(nonce);
-        self.bits[word] |= bit;
+        if let Some(w) = self.bits.get_mut(word) {
+            *w |= bit;
+        }
     }
 }

cmux-tui/crates/cmux-tui/src/cli/app/group_create.rs

@@ -19,14 +19,14 @@ pub(super) fn parse(args: &[String]) -> Result<Option<AppCommand>, UsageError> {
     if words != ["workspace", "group", "create"] {
         return Ok(None);
     }
-    let rest = &args[3..];
+    let rest = args.get(3..).unwrap_or_default();
     let mut remote = None;
     let mut parent = None;
     let mut name = None;
     let mut other = None;
     let mut index = 0;
-    while index < rest.len() {
-        let arg = rest[index].as_str();
+    while let Some(arg) = rest.get(index) {
+        let arg = arg.as_str();
         let (flag, inline) = match arg.split_once('=') {
             Some((flag, value)) if flag.starts_with("--") => (flag, Some(value.to_owned())),
             _ => (arg, None),

cmux-tui/crates/cmux-tui/src/cli/apps_list.rs

@@ -119,8 +119,10 @@ pub(super) fn info_text(detail: &Value) -> String {
         detail["summary"].as_str().unwrap_or(""),
         detail["tier"].as_str().unwrap_or(""),
     );
-    let targets: Vec<&str> = detail["deploy"]["targets"]
-        .as_array()
+    let targets: Vec<&str> = detail
+        .get("deploy")
+        .and_then(|deploy| deploy.get("targets"))
+        .and_then(Value::as_array)
         .into_iter()
         .flatten()
         .filter_map(Value::as_str)

cmux-tui/crates/cmux-tui/src/cli/automation.rs

@@ -151,20 +151,17 @@ const SPEC_FLAGS: &[&str] = &["hourly", "manual", "paused"];
 fn take_target(args: &[String]) -> Result<(bool, Vec<String>), Failure> {
     let mut out = Vec::with_capacity(args.len());
     let mut target = None;
-    let mut i = 0;
-    while i < args.len() {
-        let arg = &args[i];
+    let mut words = args.iter();
+    while let Some(arg) = words.next() {
         if let Some(v) = arg.strip_prefix("--target=") {
             target = Some(v.to_string());
         } else if arg == "--target" {
-            i += 1;
-            target = Some(args.get(i).cloned().ok_or_else(|| {
+            target = Some(words.next().cloned().ok_or_else(|| {
                 Failure::Usage(messages().missing_value.replace("{flag}", "target"))
             })?);
         } else {
             out.push(arg.clone());
         }
-        i += 1;
     }
     match target.as_deref() {
         None | Some("local" | "this-mac") => Ok((false, out)),
@@ -1274,4 +1271,19 @@ mod tests {
         assert_eq!(parse_duration("1d").ok(), Some(86_400));
         assert!(parse_duration("soon").is_err());
     }
+
+    #[test]
+    fn target_is_taken_out_of_the_words_in_both_forms() {
+        let words = |w: &[&str]| w.iter().map(|s| s.to_string()).collect::<Vec<_>>();
+        let taken = |w: &[&str]| take_target(&words(w)).ok();
+        assert_eq!(taken(&["list"]), Some((false, words(&["list"]))));
+        assert_eq!(
+            taken(&["list", "--target", "cloud", "--json"]),
+            Some((true, words(&["list", "--json"])))
+        );
+        assert_eq!(taken(&["--target=cloud", "list"]), Some((true, words(&["list"]))));
+        assert_eq!(taken(&["list", "--target", "this-mac"]), Some((false, words(&["list"]))));
+        assert!(matches!(take_target(&words(&["list", "--target"])), Err(Failure::Usage(_))));
+        assert!(matches!(take_target(&words(&["--target", "mars"])), Err(Failure::Usage(_))));
+    }
 }

cmux-tui/crates/cmux-tui/src/cli/chief/mod.rs

@@ -193,7 +193,7 @@ fn run(global: GlobalArgs, args: &[String]) -> i32 {
         return relocate::run(&global, &args[1..]);
     }
     if args.first().is_some_and(|word| word == "acp") {
-        return acp::run(&global, &args[1..]);
+        return acp::run(&global, args.get(1..).unwrap_or_default());
     }
     if args.first().is_some_and(|word| word == "usage") {
         return usage::run(&global, &args[1..]);

cmux-tui/crates/cmux-tui/src/cli/chief/pipe.rs

@@ -179,7 +179,7 @@ pub(super) fn follow(
         let Some(event) = adapt(&line, &session.conversation) else { continue };
         turn.on(&event);
         // A snapshot after a gap can add several replies at once.
-        for reply in &turn.replies[printed..] {
+        for reply in turn.replies.get(printed..).unwrap_or_default() {
             out.message(reply);
             drafts.on_message(reply);
         }