fix(rollout): decode resume tail through canonical path

Author: offx366

codex-rs/rollout/src/ordinal.rs

@@ -8,9 +8,11 @@ use std::path::Path;
 
 use codex_protocol::protocol::HistoryPosition;
 use codex_protocol::protocol::ThreadHistoryMode;
+use serde_json::Value;
 
 use crate::RolloutItem;
 use crate::RolloutLine;
+use crate::decode_rollout_line;
 use crate::reverse_jsonl_scanner::ReverseJsonlScanner;
 use crate::reverse_jsonl_scanner::ScanOutcome;
 
@@ -67,8 +69,11 @@ pub(crate) fn ordinal_state_for_rollout(
 
     let mut scanner = ReverseJsonlScanner::new(file)?;
     let record = loop {
-        match scanner.scan_next::<RolloutLine>()? {
-            Some(ScanOutcome::Parsed(record)) => break record,
+        match scanner.scan_next::<Value>()? {
+            Some(ScanOutcome::Parsed(value)) => match decode_rollout_line(value) {
+                Ok(record) => break record,
+                Err(_) => continue,
+            },
             Some(ScanOutcome::Rejected(_)) => continue,
             None => {
                 return Err(io::Error::other(format!(

codex-rs/rollout/src/recorder_tests.rs

@@ -995,6 +995,38 @@ async fn resumed_paginated_rollout_continues_after_ordinal_gap() -> std::io::Res
     recorder.shutdown().await
 }
 
+#[tokio::test]
+async fn resumed_paginated_rollout_decodes_float_rate_limit_tail_before_assigning_ordinal()
+-> std::io::Result<()> {
+    let home = TempDir::new().expect("temp dir");
+    let config = test_config(home.path());
+    let rollout_path = home.path().join("rollout.jsonl");
+    write_paginated_rollout(&rollout_path, ThreadId::new(), &[4])?;
+
+    let token_count = r#"{"timestamp":"2026-07-09T00:00:05Z","ordinal":5,"type":"event_msg","payload":{"type":"token_count","info":null,"rate_limits":{"limit_id":null,"limit_name":null,"primary":{"used_percent":49.0,"window_minutes":60,"resets_at":1800000000},"secondary":null,"credits":null,"individual_limit":null,"spend_control_reached":null,"plan_type":null,"rate_limit_reached_type":null}}}"#;
+    assert!(serde_json::from_str::<RolloutLine>(token_count).is_err());
+    let mut file = fs::OpenOptions::new().append(true).open(&rollout_path)?;
+    writeln!(file, "{token_count}")?;
+    drop(file);
+
+    let recorder =
+        RolloutRecorder::new(&config, RolloutRecorderParams::resume(rollout_path.clone())).await?;
+    recorder
+        .record_canonical_items(&[agent_message_item("after-resume")])
+        .await?;
+    recorder.flush().await?;
+
+    let ordinals = fs::read_to_string(&rollout_path)?
+        .lines()
+        .map(serde_json::from_str::<serde_json::Value>)
+        .collect::<Result<Vec<_>, _>>()?
+        .into_iter()
+        .map(|value| value.get("ordinal").and_then(serde_json::Value::as_u64))
+        .collect::<Vec<_>>();
+    assert_eq!(ordinals, vec![Some(0), Some(4), Some(5), Some(6)]);
+    recorder.shutdown().await
+}
+
 #[tokio::test]
 async fn resumed_paginated_rollout_repairs_unsafe_tail() -> std::io::Result<()> {
     let valid_unterminated = serde_json::to_string(&RolloutLine {