f: don't assert in production code

Author: arik-so

lightning/src/ln/onion_utils.rs

@@ -431,16 +431,22 @@ pub(super) fn construct_trampoline_onion_packet(
 ) -> Result<msgs::TrampolineOnionPacket, ()> {
 	let minimum_packet_length = payloads.iter().map(|p| p.serialized_length() + 32).sum();
 
-	assert!(
+	debug_assert!(
 		minimum_packet_length < ONION_DATA_LEN,
 		"Trampoline onion packet must be smaller than outer onion"
 	);
+	if minimum_packet_length >= ONION_DATA_LEN {
+		return Err(());
+	}
 
 	let packet_length = usize::from(length.unwrap_or(minimum_packet_length as u16));
-	assert!(
+	debug_assert!(
 		packet_length >= minimum_packet_length,
 		"Packet length cannot be smaller than the payloads require."
 	);
+	if packet_length < minimum_packet_length {
+		return Err(());
+	}
 
 	let mut packet_data = vec![0u8; packet_length];
 	let mut chacha = ChaCha20::new(&prng_seed, &[0; 8]);