routing: skip amtInRange for custom HTLCs

We might be trying to send an invoice amount that's greater than the size of the channel, but once you factor in the custom channel logic, an actual HTLC can be sent over the channel to pay that larger payment.

As a result, we'll skip over this check if a have a custom HTLC.

Author: Roasbeef

routing/unified_edges.go

@@ -234,7 +234,7 @@ func (u *edgeUnifier) getEdgeLocal(netAmtReceived lnwire.MilliSatoshi,
 		amt := netAmtReceived + lnwire.MilliSatoshi(inboundFee)
 
 		// Check valid amount range for the channel.
-		if !edge.amtInRange(amt) {
+		if htlcBlob.IsNone() && !edge.amtInRange(amt) {
 			log.Debugf("Amount %v not in range for edge %v",
 				netAmtReceived, edge.policy.ChannelID)