Comments

codex-rs/core/src/codex.rs

@@ -4679,12 +4679,10 @@ async fn maybe_run_previous_model_inline_compact(
 
     match run_auto_compact(
         sess,
+        // We use previous turn context here because we compact with the previous model
         &previous_turn_context,
         AutoCompactCallsite::PreTurnExcludingIncomingUserMessage,
-        // Even though incoming turn items are excluded here, this pass can be the only
-        // compaction run before submission. Reinject canonical context so unchanged
-        // model-visible instructions remain present if no follow-up pre-turn compaction
-        // is needed.
+        // User message and turn context diff is injected in the pre-compaction NotNeeded case later
         TurnContextReinjection::ReinjectAboveLastRealUser,
         None,
     )