fix(compression): preserve messages across session rotation (flush-before-rotate + /compress rewrite guard)#48584
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Conversation
compress_context() rotates the session (end_session -> create_session) mid-turn when auto-compress triggers, but never called _flush_messages_to_session_db() first. Messages generated during the current turn that hadn't been persisted to state.db were silently lost. The same bug existed in cli.py:new_session() (/new command). Both paths now flush un-persisted messages before ending the old session.
… skipped The manual /compress handler called rewrite_transcript() unconditionally on the session id returned by _compress_context(). When rotation does not occur (e.g. _session_db unavailable, or the DB split raised), session_id is unchanged and rewrite_transcript() DELETEs the original messages and replaces them with only the compressed summary — permanent data loss (#44794, #39704). Guard the rewrite on actual rotation: only overwrite when _compress_context produced a new session id. Otherwise leave the original transcript intact and log a warning.
Contributor
🔎 Lint report:
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| Rule | Count |
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unresolved-attribute |
2 |
First entries
tests/run_agent/test_credits_notices_toggle.py:76: [unresolved-attribute] unresolved-attribute: Unresolved attribute `_credits_session_start_micros` on type `AIAgent`
run_agent.py:2941: [unresolved-attribute] unresolved-attribute: Object of type `Self@get_credits_spent_micros` has no attribute `_credits_session_start_micros`
✅ Fixed issues (1):
| Rule | Count |
|---|---|
invalid-assignment |
1 |
First entries
tests/run_agent/test_credits_notices_toggle.py:76: [invalid-assignment] invalid-assignment: Object of type `None` is not assignable to attribute `_credits_session_start_micros` of type `int`
Unchanged: 5774 pre-existing issues carried over.
Diagnostics are surfaced as warnings — this check never fails the build.
alt-glitch
added
type/bug
This was referenced Jun 18, 2026
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Summary
Compression and
/compressno longer lose conversation messages fromstate.dbwhen a session rotates. Two distinct data-loss paths in the same family are closed.Changes
agent/conversation_compression.py+cli.py: flush un-persisted current-turn messages to the old session beforeend_session()rotates the session id. Auto-compression (and/new) can fire mid-turn before_persist_sessionruns at turn-exit, so the turn's messages were never written to SQLite and were lost on rotation. (Salvaged from @kyssta-exe's fix(agent): flush un-persisted messages before session rotation (#47202) #47215, fixes Context compression silently loses unflushed messages (end_session without flush) #47202 and Mid-turn compression loses messages: flush before session rotation #46567.)gateway/slash_commands.py: guard the manual/compressrewrite_transcript()on actual rotation. When_compress_context()can't rotate (e.g._session_dbunavailable or the DB split raised),session_idis unchanged and the unconditionalrewrite_transcript()would DELETE the original messages and replace them with only the compressed summary — permanent data loss. Now the rewrite only runs when rotation produced a new session id; otherwise the original transcript is left intact. (Fixes /compress deletes original messages from state.db when session rotation fails #44794, Bug: Session Hygiene compression overwrites original messages when _session_db is None #39704.)Validation
/compresswith rotation skippedHERMES_HOME, realSessionDB+ real_flush_messages_to_session_db): 3 current-turn messages incl. final answer persist to the old session beforeend_session; 2 history messages correctly skipped by identity tracking.tests/gateway/test_compress_command.py,test_compression_session_id_persistence.py,test_compression_failure_session_sync.py— 9/9 pass.Issues
Fixes #47202, #46567, #44794, #39704.
Authorship: first commit is @kyssta-exe's (cherry-picked, #47215); rewrite-guard commit is ours.
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