lnworker: always call check_received_htlc (no only for MPP)

This will be a generic placeholder to decide if we need to wait
before settling a payment (to be used with hold invoices and
bundled payments)

electrum/lnpeer.py

@@ -1804,14 +1804,14 @@ class Peer(Logger):
             # TODO fail here if invoice has set PAYMENT_SECRET_REQ
             payment_secret_from_onion = None
 
-        if total_msat > amt_to_forward:
-            mpp_status = self.lnworker.check_received_mpp_htlc(payment_secret_from_onion, chan.short_channel_id, htlc, total_msat)
-            if mpp_status is None:
-                return None, None
-            if mpp_status is False:
-                log_fail_reason(f"MPP_TIMEOUT")
-                raise OnionRoutingFailure(code=OnionFailureCode.MPP_TIMEOUT, data=b'')
-            assert mpp_status is True
+        payment_status = self.lnworker.check_received_htlc(payment_secret_from_onion, chan.short_channel_id, htlc, total_msat)
+        if payment_status is None:
+            return None, None
+        elif payment_status is False:
+            log_fail_reason(f"MPP_TIMEOUT")
+            raise OnionRoutingFailure(code=OnionFailureCode.MPP_TIMEOUT, data=b'')
+        else:
+            assert payment_status is True
 
         # if there is a trampoline_onion, maybe_fulfill_htlc will be called again
         if processed_onion.trampoline_onion_packet:

electrum/lnworker.py

@@ -1888,8 +1888,15 @@ class LNWallet(LNWorker):
         if write_to_disk:
             self.wallet.save_db()
 
-    def check_received_mpp_htlc(self, payment_secret, short_channel_id, htlc: UpdateAddHtlc, expected_msat: int) -> Optional[bool]:
-        """ return MPP status: True (accepted), False (expired) or None """
+    def check_received_htlc(self, payment_secret, short_channel_id, htlc: UpdateAddHtlc, expected_msat: int) -> Optional[bool]:
+        """ return MPP status: True (accepted), False (expired) or None (waiting)
+        """
+
+        amt_to_forward = htlc.amount_msat # check this
+        if amt_to_forward >= expected_msat:
+            # not multi-part
+            return True
+
         payment_hash = htlc.payment_hash
         is_expired, is_accepted, htlc_set = self.received_mpp_htlcs.get(payment_secret, (False, False, set()))
         if self.get_payment_status(payment_hash) == PR_PAID:

electrum/tests/test_lnpeer.py

@@ -247,7 +247,7 @@ class MockLNWallet(Logger, EventListener, NetworkRetryManager[LNPeerAddr]):
     set_request_status = LNWallet.set_request_status
     set_payment_status = LNWallet.set_payment_status
     get_payment_status = LNWallet.get_payment_status
-    check_received_mpp_htlc = LNWallet.check_received_mpp_htlc
+    check_received_htlc = LNWallet.check_received_htlc
     htlc_fulfilled = LNWallet.htlc_fulfilled
     htlc_failed = LNWallet.htlc_failed
     save_preimage = LNWallet.save_preimage