Save complete trajectory in presence of history truncation (#6751)

Co-authored-by: Engel Nyst <enyst@users.noreply.github.com>

openhands/core/main.py

@@ -27,7 +27,6 @@ from openhands.events.action.action import Action
 from openhands.events.event import Event
 from openhands.events.observation import AgentStateChangedObservation
 from openhands.events.serialization import event_from_dict
-from openhands.events.serialization.event import event_to_trajectory
 from openhands.io import read_input, read_task
 from openhands.runtime.base import Runtime
 
@@ -167,6 +166,8 @@ async def run_controller(
         # NOTE: the saved state does not include delegates events
         end_state.save_to_session(event_stream.sid, event_stream.file_store)
 
+    await controller.close(set_stop_state=False)
+
     state = controller.get_state()
 
     # save trajectories if applicable
@@ -177,7 +178,7 @@ async def run_controller(
         else:
             file_path = config.save_trajectory_path
         os.makedirs(os.path.dirname(file_path), exist_ok=True)
-        histories = [event_to_trajectory(event) for event in state.history]
+        histories = controller.get_trajectory()
         with open(file_path, 'w') as f:
             json.dump(histories, f)