lnpeer: if close_channel times out, check unconfirmed_closing_txid before raising an exception

electrum/lnchannel.py

@@ -304,7 +304,7 @@ class AbstractChannel(Logger, ABC):
                 # we must not trust the server with unconfirmed transactions,
                 # because the state transition is irreversible. if the remote
                 # force closed, we remain OPEN until the closing tx is confirmed
-                self.closing_detected = True
+                self.unconfirmed_closing_txid = closing_txid
                 if self.lnworker:
                     util.trigger_callback('channel', self.lnworker.wallet, self)
 
@@ -339,7 +339,7 @@ class AbstractChannel(Logger, ABC):
 
     def get_state_for_GUI(self) -> str:
         cs = self.get_state()
-        if cs == ChannelState.OPEN and self.closing_detected:
+        if cs == ChannelState.OPEN and self.unconfirmed_closing_txid:
             return 'FORCE-CLOSING'
         return cs.name
 
@@ -419,7 +419,7 @@ class ChannelBackup(AbstractChannel):
         self.config = {}
         if self.is_imported:
             self.init_config(cb)
-        self.closing_detected = False # not a state, only for GUI
+        self.unconfirmed_closing_txid = None # not a state, only for GUI
 
     def init_config(self, cb):
         self.config[LOCAL] = LocalConfig.from_seed(
@@ -553,7 +553,7 @@ class Channel(AbstractChannel):
         self._receive_fail_reasons = {}  # type: Dict[int, (bytes, OnionRoutingFailure)]
         self._ignore_max_htlc_value = False  # used in tests
         self.should_request_force_close = False
-        self.closing_detected = False # not a state, only for GUI
+        self.unconfirmed_closing_txid = None # not a state, only for GUI
 
     def has_onchain_backup(self):
         return self.storage.get('has_onchain_backup', False)
@@ -735,7 +735,7 @@ class Channel(AbstractChannel):
 
     def get_state_for_GUI(self):
         cs_name = super().get_state_for_GUI()
-        if self.is_closed() or self.closing_detected:
+        if self.is_closed() or self.unconfirmed_closing_txid:
             return cs_name
         ps = self.peer_state
         if ps != PeerState.GOOD:

electrum/lnpeer.py

@@ -1692,19 +1692,23 @@ class Peer(Logger):
         self.shutdown_received[chan_id] = asyncio.Future()
         await self.send_shutdown(chan)
         payload = await self.shutdown_received[chan_id]
-        txid = await self._shutdown(chan, payload, is_local=True)
+        try:
-        self.logger.info(f'({chan.get_id_for_log()}) Channel closed {txid}')
+            txid = await self._shutdown(chan, payload, is_local=True)
+            self.logger.info(f'({chan.get_id_for_log()}) Channel closed {txid}')
+        except asyncio.TimeoutError:
+            txid = chan.unconfirmed_closing_txid
+            self.logger.info(f'({chan.get_id_for_log()}) did not send closing_signed, {txid}')
+            if txid is None:
+                raise Exception('The remote peer did not send their final signature. The channel may not have been be closed')
         return txid
 
     async def on_shutdown(self, chan: Channel, payload):
         their_scriptpubkey = payload['scriptpubkey']
         their_upfront_scriptpubkey = chan.config[REMOTE].upfront_shutdown_script
-
         # BOLT-02 check if they use the upfront shutdown script they advertized
         if their_upfront_scriptpubkey:
             if not (their_scriptpubkey == their_upfront_scriptpubkey):
                 raise UpfrontShutdownScriptViolation("remote didn't use upfront shutdown script it commited to in channel opening")
-
         # BOLT-02 restrict the scriptpubkey to some templates:
         if not (match_script_against_template(their_scriptpubkey, transaction.SCRIPTPUBKEY_TEMPLATE_WITNESS_V0)
                 or match_script_against_template(their_scriptpubkey, transaction.SCRIPTPUBKEY_TEMPLATE_P2SH)
@@ -1731,13 +1735,11 @@ class Peer(Logger):
     async def send_shutdown(self, chan: Channel):
         if not self.can_send_shutdown(chan):
             raise Exception('cannot send shutdown')
-
         if chan.config[LOCAL].upfront_shutdown_script:
             scriptpubkey = chan.config[LOCAL].upfront_shutdown_script
         else:
             scriptpubkey = bfh(bitcoin.address_to_script(chan.sweep_address))
         assert scriptpubkey
-
         # wait until no more pending updates (bolt2)
         chan.set_can_send_ctx_updates(False)
         while chan.has_pending_changes(REMOTE):
@@ -1761,7 +1763,6 @@ class Peer(Logger):
         else:
             our_scriptpubkey = bfh(bitcoin.address_to_script(chan.sweep_address))
         assert our_scriptpubkey
-
         # estimate fee of closing tx
         our_sig, closing_tx = chan.make_closing_tx(our_scriptpubkey, their_scriptpubkey, fee_sat=0)
         fee_rate = self.network.config.fee_per_kb()