f - update comments and remove redundant check

Author: elnosh

fuzz/src/full_stack.rs

@@ -1180,13 +1180,13 @@ fn two_peer_forwarding_seed() -> Vec<u8> {
 
 	// inbound read from peer id 1 of len 18
 	ext_from_hex("030112", &mut test);
-	// message header indicating message length 274
+	// message header indicating message length 278
 	ext_from_hex("0116 01000000000000000000000000000000", &mut test);
 	// inbound read from peer id 1 of len 255
 	ext_from_hex("0301ff", &mut test);
 	// beginning of accept_channel
 	ext_from_hex("0021 0000000000000000000000000000000000000000000000000000000000000e12 0000000000000162 00000000004c4b40 00000000000003e8 00000000000003e8 00000002 03f0 0005 030000000000000000000000000000000000000000000000000000000000000100 030000000000000000000000000000000000000000000000000000000000000200 030000000000000000000000000000000000000000000000000000000000000300 030000000000000000000000000000000000000000000000000000000000000400 030000000000000000000000000000000000000000000000000000000000000500 02660000000000000000000000000000", &mut test);
-	// inbound read from peer id 1 of len 35
+	// inbound read from peer id 1 of len 39
 	ext_from_hex("030127", &mut test);
 	// rest of accept_channel and mac
 	ext_from_hex(

lightning/src/ln/channel.rs

@@ -11982,12 +11982,6 @@ where
 		let holder_selected_channel_reserve_satoshis = get_v2_channel_reserve_satoshis(
 			channel_value_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS);
 
-		// First check the channel type is known, failing before we do anything else if we don't
-		// support this channel type.
-		if msg.common_fields.channel_type.is_none() {
-			return Err(ChannelError::close(format!("Rejecting V2 channel {} missing channel_type",
-				msg.common_fields.temporary_channel_id)))
-		}
 		let channel_type = channel_type_from_open_channel(&msg.common_fields, our_supported_features)?;
 
 		let counterparty_pubkeys = ChannelPublicKeys {

lightning/src/ln/msgs.rs

@@ -243,9 +243,6 @@ pub struct CommonOpenChannelFields {
 	/// collaboratively close
 	pub shutdown_scriptpubkey: Option<ScriptBuf>,
 	/// The channel type that this channel will represent
-	///
-	/// If this is `None`, we derive the channel type from the intersection of our
-	/// feature bits with our counterparty's feature bits from the [`Init`] message.
 	pub channel_type: Option<ChannelTypeFeatures>,
 }
 
@@ -356,9 +353,7 @@ pub struct CommonAcceptChannelFields {
 	/// Optionally, a request to pre-set the to-channel-acceptor output's scriptPubkey for when we
 	/// collaboratively close
 	pub shutdown_scriptpubkey: Option<ScriptBuf>,
-	/// The channel type that this channel will represent. If none is set, we derive the channel
-	/// type from the intersection of our feature bits with our counterparty's feature bits from
-	/// the Init message.
+	/// The channel type that this channel will represent
 	///
 	/// This is required to match the equivalent field in [`OpenChannel`] or [`OpenChannelV2`]'s
 	/// [`CommonOpenChannelFields::channel_type`].