Fix graceful shutdown for lightning swaps

electrum/lnworker.py

@@ -967,6 +967,8 @@ class LNWallet(LNWorker):
         if self.lnwatcher:
             await self.lnwatcher.stop()
             self.lnwatcher = None
+        if self.swap_manager:  # may not be present in tests
+            await self.swap_manager.stop()
 
     async def wait_for_received_pending_htlcs_to_get_removed(self):
         assert self.stopping_soon is True

electrum/submarine_swaps.py

@@ -219,6 +219,9 @@ class SwapManager(Logger):
         finally:
             self.logger.info("taskgroup stopped.")
 
+    async def stop(self):
+        await self.taskgroup.cancel_remaining()
+
     async def pay_invoice(self, key):
         self.logger.info(f'trying to pay invoice {key}')
         self.invoices_to_pay[key] = 1000000000000 # lock

electrum/tests/test_lnpeer.py

@@ -147,6 +147,7 @@ class MockLNWallet(Logger, EventListener, NetworkRetryManager[LNPeerAddr]):
         self.network = MockNetwork(tx_queue, config=self.config)
         self.taskgroup = OldTaskGroup()
         self.lnwatcher = None
+        self.swap_manager = None
         self.listen_server = None
         self._channels = {chan.channel_id: chan for chan in chans}
         self.payment_info = {}