Duplicate transcript on cold resume with rotating compression

Fixes on record

Merged to main. A stamp counts the issues a fix is linked to.

• #68205 fix(agent): don't re-append persisted transcript on cold-resume rotating compression (#68196)

  merged to main

  files: agent/conversation_compression.py, tests/agent/test_rotation_flush_persisted_boundary_68196.py

  Show the diff

  • agent/conversation_compression.py

    @@ -1236,8 +1236,29 @@ def _release_lock() -> None:
                         # Flush any un-persisted current-turn messages to the OLD
                         # session before ending it, so they survive in the preserved
                         # parent transcript (#47202). (In-place skips this — see above.)
    +                    #
    +                    # Pass the already-durable prefix as conversation_history so
    +                    # the flush skips it by identity (#68196). Preflight
    +                    # compression runs BEFORE the normal turn flush has stamped
    +                    # the cold-resumed history dicts with _DB_PERSISTED_MARKER, so
    +                    # without a boundary _flush_messages_to_session_db treats every
    +                    # restored row as new and re-appends the whole transcript to
    +                    # the parent. turn_context anchors _persist_user_message_idx at
    +                    # the current-turn user message before preflight runs, so
    +                    # messages[:idx] is exactly the persisted prefix; only the
    +                    # current turn's new messages get written.
    +                    current_idx = getattr(agent, "_persist_user_message_idx", None)
    +                    persisted_history = (
    +                        messages[:current_idx]
    +                        if isinstance(current_idx, int)
    +                        and 0 <= current_idx <= len(messages)
    +                        else None
    +                    )
                         try:
    -                        agent._flush_messages_to_session_db(messages)
    +                        agent._flush_messages_to_session_db(
    +                            messages,
    +                            conversation_history=persisted_history,
    +                        )
                         except Exception:
                             pass  # best-effort — don't block compression on a flush error
                         # Propagate title to the new session with auto-numbering

  • tests/agent/test_rotation_flush_persisted_boundary_68196.py

    @@ -0,0 +1,118 @@
    +"""Regression (#68196): rotating preflight compression must not re-append the
    +already-persisted transcript to the parent session on cold resume.
    +
    +On the first turn after a cold Desktop resume, the stored rows are handed to
    +``run_conversation()`` as ``conversation_history`` and live in the message list
    +as plain dicts that have NOT yet been stamped with ``_DB_PERSISTED_MARKER`` —
    +the normal turn flush (which stamps them) runs *after* preflight compression.
    +
    +The legacy rotation branch in ``agent/conversation_compression.py`` flushes the
    +current turn to the OLD session before ending it (#47202). It used to call
    +``agent._flush_messages_to_session_db(messages)`` with no history boundary, so
    +``_flush_messages_to_session_db`` saw an empty ``history_ids`` set and treated
    +every restored row as new — durably appending the whole transcript to the
    +parent a second time. The fix passes ``messages[:_persist_user_message_idx]``
    +(the already-durable prefix ``turn_context`` anchors before preflight runs) as
    +``conversation_history`` so only the current turn's new messages are written.
    +
    +Without the fix the parent grows to 5 rows (the two originals + a duplicate of
    +both + the new turn). With it the parent holds exactly the two originals plus
    +the single new turn.
    +"""
    +
    +from __future__ import annotations
    +
    +import os
    +import time
    +from pathlib import Path
    +from unittest.mock import MagicMock, patch
    +
    +from hermes_state import SessionDB
    +
    +
    +def _build_agent_with_db(db: SessionDB, session_id: str):
    +    """Build an AIAgent wired to ``db`` and pinned to ``session_id``.
    +
    +    Mirrors the helper in ``test_compression_concurrent_fork.py``: stub the
    +    compressor so it returns deterministic output without an LLM call, and pin
    +    ``compression_in_place=False`` so the legacy rotation path is exercised
    +    regardless of the global default.
    +    """
    +    with patch.dict(os.environ, {"OPENROUTER_API_KEY": "[redacted:secret-assignment]"}):
    +        from run_agent import AIAgent
    +
    +        agent = AIAgent(
    +            api_key="[redacted:secret-assignment]",
    +            base_url="https://openrouter.ai/api/v1",
    +            model="test/model",
    +            quiet_mode=True,
    +            session_db=db,
    +            session_id=session_id,
    +            skip_context_files=True,
    +            skip_memory=True,
    +        )
    +
    +    compressor = MagicMock()
    +
    +    def _compress(*_a, **_kw):
    +        time.sleep(0.01)
    +        return [
    +            {"role": "user", "content": "[CONTEXT COMPACTION] summary"},
    +            {"role": "user", "content": "tail"},
    +        ]
    +
    +    compressor.compress.side_effect = _compress
    +    compressor.compression_count = 1
    +    compressor.last_prompt_tokens = 0
    +    compressor.last_completion_tokens = 0
    +    compressor._last_summary_error = None
    +    compressor._last_compress_aborted = False
    +    compressor._last_aux_model_failure_model = None
    +    compressor._last_aux_model_failure_error = None
    +    agent.context_compressor = compressor
    +    agent.compression_in_place = False
    +    return agent
    +
    +
    +def _contents(rows):
    +    return [r.get("content") for r in rows]
    +
    +
    +def test_rotation_flush_does_not_duplicate_persisted_prefix(tmp_path: Path) -> None:
    +    """Cold-resume + rotating preflight compression keeps the parent transcript
    +    at (persisted prefix + one new turn) — no second copy of the durable rows."""
    +    db = SessionDB(db_path=tmp_path / "state.db")
    +
    +    parent_sid = "COLD_RESUME_PARENT"
    +    db.create_session(parent_sid, source="desktop")
    +
    +    # Two durable rows already in the parent.
    +    db.append_message(parent_sid, "user", "persisted question")
    +    db.append_message(parent_sid, "assistant", "persisted answer")
    +
    +    # Cold resume: the stored rows come back as plain dicts, unstamped, and the
    +    # live turn appends one new user message on top.
    +    loaded = db.get_messages_as_conversation(parent_sid)
    +    assert _contents(loaded) == ["persisted question", "persisted answer"]
    +    messages = [*loaded, {"role": "user", "content": "new turn"}]
    +
    +    agent = _build_agent_with_db(db, parent_sid)
    +    # turn_context anchors this at the current-turn user message before preflight
    +    # compression runs; emulate that anchor.
    +    agent._persist_user_message_idx = len(messages) - 1
    +
    +    agent._compress_context(messages, "sys", approx_tokens=[redacted:secret-assignment]
    +
    +    # The flush at the rotation boundary lands on the OLD (parent) session,
    +    # which is then ended. Read it back verbatim (include_inactive to be robust
    +    # to the end_session bookkeeping).
    +    parent_rows = db.get_messages_as_conversation(parent_sid, include_inactive=True)
    +    contents = _contents(parent_rows)
    +
    +    assert contents.count("persisted question") == 1, (
    +        "Rotation flush re-appended the already-persisted prefix to the parent "
    +        f"(#68196). Parent transcript is {contents!r}; expected the two durable "
    +        "rows plus only the new turn."
    +    )
    +    assert contents.count("persisted answer") == 1
    +    assert contents == ["persisted question", "persisted answer", "new turn"]