split lnpeer.fail_htlc into two methods with less parameters

electrum/lnpeer.py

@@ -1314,24 +1314,25 @@ class Peer(Logger):
                           id=htlc_id,
                           payment_preimage=preimage)
 
-    def fail_htlc(self, *, chan: Channel, htlc_id: int, onion_packet: Optional[OnionPacket],
-                  reason: Optional[OnionRoutingFailureMessage], error_bytes: Optional[bytes]):
-        self.logger.info(f"fail_htlc. chan {chan.short_channel_id}. htlc_id {htlc_id}. reason: {reason}")
+    def fail_htlc(self, *, chan: Channel, htlc_id: int, error_bytes: bytes):
+        self.logger.info(f"fail_htlc. chan {chan.short_channel_id}. htlc_id {htlc_id}.")
         assert chan.can_send_ctx_updates(), f"cannot send updates: {chan.short_channel_id}"
         chan.fail_htlc(htlc_id)
-        if onion_packet and reason:
-            error_bytes = construct_onion_error(reason, onion_packet, our_onion_private_key=self.privkey)
-        if error_bytes:
-            self.send_message("update_fail_htlc",
+        self.send_message(
+            "update_fail_htlc",
             channel_id=chan.channel_id,
             id=htlc_id,
             len=len(error_bytes),
             reason=error_bytes)
-        else:
-            assert reason is not None
+
+    def fail_malformed_htlc(self, *, chan: Channel, htlc_id: int, reason: OnionRoutingFailureMessage):
+        self.logger.info(f"fail_malformed_htlc. chan {chan.short_channel_id}. htlc_id {htlc_id}.")
+        assert chan.can_send_ctx_updates(), f"cannot send updates: {chan.short_channel_id}"
+        chan.fail_htlc(htlc_id)
         if not (reason.code & OnionFailureCodeMetaFlag.BADONION and len(reason.data) == 32):
             raise Exception(f"unexpected reason when sending 'update_fail_malformed_htlc': {reason!r}")
-            self.send_message("update_fail_malformed_htlc",
+        self.send_message(
+            "update_fail_malformed_htlc",
             channel_id=chan.channel_id,
             id=htlc_id,
             sha256_of_onion=reason.data,
@@ -1574,11 +1575,18 @@ class Peer(Logger):
                             self.fulfill_htlc(chan, htlc.htlc_id, preimage)
                             done.add(htlc_id)
                     if error_reason or error_bytes:
-                        self.fail_htlc(chan=chan,
+                        if onion_packet and error_reason:
+                            error_bytes = construct_onion_error(error_reason, onion_packet, our_onion_private_key=self.privkey)
+                        if error_bytes:
+                            self.fail_htlc(
+                                chan=chan,
                                 htlc_id=htlc.htlc_id,
-                                       onion_packet=onion_packet,
-                                       reason=error_reason,
                                 error_bytes=error_bytes)
+                        else:
+                            self.fail_malformed_htlc(
+                                chan=chan,
+                                htlc_id=htlc.htlc_id,
+                                reason=error_reason)
                         done.add(htlc_id)
                 # cleanup
                 for htlc_id in done: