Throw error when last record does not contain any valid acknowledged id

src/AsapoWorker/worker.py

@@ -84,6 +84,11 @@ class SerialWorker(Worker):
                     last_output_metadata["meta"]["acknowledged_ids"])
             except KeyError:
                 last_acknowledged_id = 0
+            if last_acknowledged_id < 0:
+                raise ValueError(
+                    "No valid acknowledged id in last record of output stream "
+                    "last_acknowledged_id=%s",
+                    last_acknowledged_id)
             input_start_id = last_acknowledged_id + 1
             output_start_id = last_output_id + 1
             return input_start_id, output_start_id