f - retain to avoid extra alloc in RecipientOnionFields::check_merge

Author: alecchendev

lightning/src/ln/outbound_payment.rs

@@ -503,11 +503,7 @@ impl RecipientOnionFields {
 		if self.payment_metadata != further_htlc_fields.payment_metadata { return Err(()); }
 
 		if let (Some(tlvs), Some(further_tlvs)) = (&mut self.custom_tlvs, &further_htlc_fields.custom_tlvs) {
-			let remaining_tlvs = tlvs.iter()
-				.filter(|tlv| further_tlvs.iter().any(|further_tlv| tlv == &further_tlv))
-				.map(|tlv| tlv.clone())
-				.collect();
-			self.custom_tlvs = Some(remaining_tlvs);
+			tlvs.retain(|tlv| further_tlvs.iter().any(|further_tlv| tlv == further_tlv));
 		}
 		Ok(())
 	}