Split method to reconstruct pending HTLCs into two

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index 3236ebd..88d2e32 100644
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -315,7 +315,7 @@ impl InboundHTLCState {
 ///
 /// Useful for reconstructing the pending HTLC set on startup.
 #[derive(Debug, Clone)]
-pub(super) enum InboundUpdateAdd {
+enum InboundUpdateAdd {
 	/// The inbound committed HTLC's update_add_htlc message.
 	WithOnion { update_add_htlc: msgs::UpdateAddHTLC },
 	/// This inbound HTLC is a forward that was irrevocably committed to the outbound edge, allowing
@@ -7885,10 +7885,35 @@ where
 		Ok(())
 	}
 
-	/// Useful for reconstructing the set of pending HTLCs when deserializing the `ChannelManager`.
-	pub(super) fn inbound_committed_unresolved_htlcs(
+	/// Returns true if any committed inbound HTLCs were received pre-LDK 0.3 and cannot be used
+	/// during `ChannelManager` deserialization to reconstruct the set of pending HTLCs.
+	pub(super) fn has_legacy_inbound_htlcs(&self) -> bool {
+		self.context.pending_inbound_htlcs.iter().any(|htlc| {
+			matches!(
+				&htlc.state,
+				InboundHTLCState::Committed { update_add_htlc: InboundUpdateAdd::Legacy }
+			)
+		})
+	}
+
+	/// Returns committed inbound HTLCs whose onion has not yet been decoded and processed. Useful
+	/// for reconstructing the set of pending HTLCs when deserializing the `ChannelManager`.
+	pub(super) fn inbound_htlcs_pending_decode(
+		&self,
+	) -> impl Iterator<Item = msgs::UpdateAddHTLC> + '_ {
+		self.context.pending_inbound_htlcs.iter().filter_map(|htlc| match &htlc.state {
+			InboundHTLCState::Committed {
+				update_add_htlc: InboundUpdateAdd::WithOnion { update_add_htlc },
+			} => Some(update_add_htlc.clone()),
+			_ => None,
+		})
+	}
+
+	/// Returns committed inbound HTLCs that have been forwarded but not yet fully resolved. Useful
+	/// when reconstructing the set of pending HTLCs when deserializing the `ChannelManager`.
+	pub(super) fn inbound_forwarded_htlcs(
 		&self,
-	) -> Vec<(PaymentHash, InboundUpdateAdd)> {
+	) -> impl Iterator<Item = (PaymentHash, HTLCPreviousHopData, u64)> + '_ {
 		// We don't want to return an HTLC as needing processing if it already has a resolution that's
 		// pending in the holding cell.
 		let htlc_resolution_in_holding_cell = |id: u64| -> bool {
@@ -7902,19 +7927,17 @@ where
 			})
 		};
 
-		self.context
-			.pending_inbound_htlcs
-			.iter()
-			.filter_map(|htlc| match &htlc.state {
-				InboundHTLCState::Committed { update_add_htlc } => {
-					if htlc_resolution_in_holding_cell(htlc.htlc_id) {
-						return None;
-					}
-					Some((htlc.payment_hash, update_add_htlc.clone()))
-				},
-				_ => None,
-			})
-			.collect()
+		self.context.pending_inbound_htlcs.iter().filter_map(move |htlc| match &htlc.state {
+			InboundHTLCState::Committed {
+				update_add_htlc: InboundUpdateAdd::Forwarded { hop_data, outbound_amt_msat },
+			} => {
+				if htlc_resolution_in_holding_cell(htlc.htlc_id) {
+					return None;
+				}
+				Some((htlc.payment_hash, hop_data.clone(), *outbound_amt_msat))
+			},
+			_ => None,
+		})
 	}
 
 	/// Useful when reconstructing the set of pending HTLC forwards when deserializing the
diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index e840d70..bdc0155 100644
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -59,9 +59,9 @@ use crate::ln::chan_utils::selected_commitment_sat_per_1000_weight;
 use crate::ln::channel::QuiescentAction;
 use crate::ln::channel::{
 	self, hold_time_since, Channel, ChannelError, ChannelUpdateStatus, DisconnectResult,
-	FundedChannel, FundingTxSigned, InboundUpdateAdd, InboundV1Channel, OutboundV1Channel,
-	PendingV2Channel, ReconnectionMsg, ShutdownResult, SpliceFundingFailed, StfuResponse,
-	UpdateFulfillCommitFetch, WithChannelContext,
+	FundedChannel, FundingTxSigned, InboundV1Channel, OutboundV1Channel, PendingV2Channel,
+	ReconnectionMsg, ShutdownResult, SpliceFundingFailed, StfuResponse, UpdateFulfillCommitFetch,
+	WithChannelContext,
 };
 use crate::ln::channel_state::ChannelDetails;
 use crate::ln::funding::SpliceContribution;
@@ -10185,10 +10185,7 @@ This indicates a bug inside LDK. Please report this error at https://github.com/
 		let per_peer_state = self.per_peer_state.read().unwrap();
 		let peer_state = per_peer_state.get(&cp_id).map(|state| state.lock().unwrap()).unwrap();
 		let chan = peer_state.channel_by_id.get(&chan_id).and_then(|c| c.as_funded()).unwrap();
-		chan.inbound_committed_unresolved_htlcs()
-			.iter()
-			.filter(|(_, htlc)| matches!(htlc, InboundUpdateAdd::WithOnion { .. }))
-			.count()
+		chan.inbound_htlcs_pending_decode().count()
 	}
 
 	#[cfg(test)]
@@ -18626,33 +18623,27 @@ impl<
 					if reconstruct_manager_from_monitors {
 						if let Some(chan) = peer_state.channel_by_id.get(channel_id) {
 							if let Some(funded_chan) = chan.as_funded() {
+								// Legacy HTLCs are from pre-LDK 0.3 and cannot be reconstructed.
+								if funded_chan.has_legacy_inbound_htlcs() {
+									return Err(DecodeError::InvalidValue);
+								}
+								// Reconstruct `ChannelManager::decode_update_add_htlcs` from the serialized
+								// `Channel` as part of removing the requirement to regularly persist the
+								// `ChannelManager`.
 								let scid_alias = funded_chan.context.outbound_scid_alias();
-								let inbound_committed_update_adds =
-									funded_chan.inbound_committed_unresolved_htlcs();
-								for (payment_hash, htlc) in inbound_committed_update_adds {
-									match htlc {
-										InboundUpdateAdd::WithOnion { update_add_htlc } => {
-											// Reconstruct `ChannelManager::decode_update_add_htlcs` from the serialized
-											// `Channel` as part of removing the requirement to regularly persist the
-											// `ChannelManager`.
-											decode_update_add_htlcs
-												.entry(scid_alias)
-												.or_insert_with(Vec::new)
-												.push(update_add_htlc);
-										},
-										InboundUpdateAdd::Forwarded {
-											hop_data,
-											outbound_amt_msat,
-										} => {
-											already_forwarded_htlcs
-												.entry((hop_data.channel_id, payment_hash))
-												.or_insert_with(Vec::new)
-												.push((hop_data, outbound_amt_msat));
-										},
-										InboundUpdateAdd::Legacy => {
-											return Err(DecodeError::InvalidValue)
-										},
-									}
+								for update_add_htlc in funded_chan.inbound_htlcs_pending_decode() {
+									decode_update_add_htlcs
+										.entry(scid_alias)
+										.or_insert_with(Vec::new)
+										.push(update_add_htlc);
+								}
+								for (payment_hash, hop_data, outbound_amt_msat) in
+									funded_chan.inbound_forwarded_htlcs()
+								{
+									already_forwarded_htlcs
+										.entry((hop_data.channel_id, payment_hash))
+										.or_insert_with(Vec::new)
+										.push((hop_data, outbound_amt_msat));
 								}
 							}
 						}