Fix bug with save_funding_height, save_closing_height

(it would enter a state where only closing_height was saved)

electrum/lnchannel.py

@@ -372,6 +372,9 @@ class Channel(Logger):
     def get_closing_height(self):
         return self.storage.get('closing_height')
 
+    def delete_closing_height(self):
+        self.storage.pop('closing_height', None)
+
     def is_redeemed(self):
         return self.get_state() == channel_states.REDEEMED
 

electrum/lnwatcher.py

@@ -174,6 +174,9 @@ class LNWatcher(AddressSynchronizer):
             await self.check_onchain_situation(address, outpoint)
 
     async def check_onchain_situation(self, address, funding_outpoint):
+        # early return if address has not been added yet
+        if not self.is_mine(address):
+            return
         spenders = self.inspect_tx_candidate(funding_outpoint, 0)
         # inspect_tx_candidate might have added new addresses, in which case we return ealy
         if not self.is_up_to_date():
@@ -335,16 +338,21 @@ class LNWalletWatcher(LNWatcher):
     @ignore_exceptions
     @log_exceptions
     async def update_channel_state(self, funding_outpoint, funding_txid, funding_height, closing_txid, closing_height, keep_watching):
+        # note: state transitions are irreversible, but
+        # save_funding_height, save_closing_height are reversible
         chan = self.lnworker.channel_by_txo(funding_outpoint)
         if not chan:
             return
         if funding_height.height == TX_HEIGHT_LOCAL:
             chan.delete_funding_height()
+            chan.delete_closing_height()
             await self.lnworker.update_unfunded_channel(chan, funding_txid)
         elif closing_height.height == TX_HEIGHT_LOCAL:
             chan.save_funding_height(funding_txid, funding_height.height, funding_height.timestamp)
+            chan.delete_closing_height()
             await self.lnworker.update_open_channel(chan, funding_txid, funding_height)
         else:
+            chan.save_funding_height(funding_txid, funding_height.height, funding_height.timestamp)
             chan.save_closing_height(closing_txid, closing_height.height, closing_height.timestamp)
             await self.lnworker.update_closed_channel(chan, funding_txid, funding_height, closing_txid, closing_height, keep_watching)