fix(agent): persist repaired-turn responses (#46071)

tests/run_agent/test_compression_persistence.py

@@ -101,7 +101,7 @@ class TestFlushAfterCompression:
             )
 
     def test_flush_with_stale_history_loses_messages(self):
-        """Demonstrates the bug condition: stale conversation_history causes data loss."""
+        """Stale conversation_history no longer causes data loss."""
         from hermes_state import SessionDB
 
         with tempfile.TemporaryDirectory() as tmpdir:
@@ -120,17 +120,14 @@ class TestFlushAfterCompression:
                 {"role": "assistant", "content": "continuing..."},
             ]
 
-            # Bug: passing a conversation_history longer than compressed messages
+            # Stale history longer than messages: the old positional flush
+            # sliced past the end and dropped both messages (#46053).
             stale_history = [{"role": "user", "content": f"msg{i}"} for i in range(100)]
             agent._flush_messages_to_session_db(compressed, stale_history)
 
             rows = db.get_messages("new-session")
-            # With the stale history, flush_from = max(100, 0) = 100
-            # But compressed only has 2 entries → messages[100:] = empty
-            assert len(rows) == 0, (
-                "Expected 0 messages with stale conversation_history "
-                "(this test verifies the bug condition exists)"
-            )
+            assert len(rows) == 2
+            assert [row["content"] for row in rows] == ["summary", "continuing..."]
 
 
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