From 4345aa88ae415e558a177321a87905a134d4e24a Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Wed, 25 Nov 2020 12:23:37 -0500
Subject: [PATCH] Universally Require Writeable for ChannelKeys

It doesn't make sense to ever build a lightning node which doesn't
ever write ChannelMonitors to disk, so having a ChannelKeys object
which doesn't implement Writeable is nonsense.

Here we require Writeable for all ChannelKeys objects, simplifying
code generation for C bindings somewhat.
---
 lightning-persister/src/lib.rs        | 6 +++---
 lightning/src/chain/channelmonitor.rs | 2 +-
 lightning/src/chain/keysinterface.rs  | 2 +-
 lightning/src/ln/channel.rs           | 2 +-
 lightning/src/ln/channelmanager.rs    | 2 +-
 lightning/src/ln/onchaintx.rs         | 2 +-
 6 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/lightning-persister/src/lib.rs b/lightning-persister/src/lib.rs
index 48d4d0aa..ec08e948 100644
--- a/lightning-persister/src/lib.rs
+++ b/lightning-persister/src/lib.rs
@@ -43,7 +43,7 @@ trait DiskWriteable {
 	fn write(&self, writer: &mut fs::File) -> Result<(), Error>;
 }
 
-impl<ChanSigner: ChannelKeys + Writeable> DiskWriteable for ChannelMonitor<ChanSigner> {
+impl<ChanSigner: ChannelKeys> DiskWriteable for ChannelMonitor<ChanSigner> {
 	fn write(&self, writer: &mut fs::File) -> Result<(), Error> {
 		self.serialize_for_disk(writer)
 	}
@@ -94,7 +94,7 @@ impl FilesystemPersister {
 	}
 
 	#[cfg(test)]
-	fn load_channel_data<ChanSigner: ChannelKeys + Readable + Writeable>(&self) ->
+	fn load_channel_data<ChanSigner: ChannelKeys + Readable>(&self) ->
 		Result<HashMap<OutPoint, ChannelMonitor<ChanSigner>>, ChannelMonitorUpdateErr> {
 		if let Err(_) = fs::create_dir_all(&self.path_to_channel_data) {
 			return Err(ChannelMonitorUpdateErr::PermanentFailure);
@@ -128,7 +128,7 @@ impl FilesystemPersister {
 	}
 }
 
-impl<ChanSigner: ChannelKeys + Readable + Writeable + Send + Sync> channelmonitor::Persist<ChanSigner> for FilesystemPersister {
+impl<ChanSigner: ChannelKeys + Readable + Send + Sync> channelmonitor::Persist<ChanSigner> for FilesystemPersister {
 	fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
 		self.write_channel_data(funding_txo, monitor)
 		  .map_err(|_| ChannelMonitorUpdateErr::PermanentFailure)
diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs
index 3c58e9a2..548c8f06 100644
--- a/lightning/src/chain/channelmonitor.rs
+++ b/lightning/src/chain/channelmonitor.rs
@@ -755,7 +755,7 @@ impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
 	}
 }
 
-impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
+impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 	/// Writes this monitor into the given writer, suitable for writing to disk.
 	///
 	/// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
diff --git a/lightning/src/chain/keysinterface.rs b/lightning/src/chain/keysinterface.rs
index 085a2f87..47ad84bb 100644
--- a/lightning/src/chain/keysinterface.rs
+++ b/lightning/src/chain/keysinterface.rs
@@ -204,7 +204,7 @@ impl Readable for SpendableOutputDescriptor {
 // routine).
 // TODO: We should remove Clone by instead requesting a new ChannelKeys copy when we create
 // ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
-pub trait ChannelKeys : Send+Clone {
+pub trait ChannelKeys : Send+Clone + Writeable {
 	/// Gets the per-commitment point for a specific commitment number
 	///
 	/// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index c319c552..5477485d 100644
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -4055,7 +4055,7 @@ impl Readable for InboundHTLCRemovalReason {
 	}
 }
 
-impl<ChanSigner: ChannelKeys + Writeable> Writeable for Channel<ChanSigner> {
+impl<ChanSigner: ChannelKeys> Writeable for Channel<ChanSigner> {
 	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 		// Note that we write out as if remove_uncommitted_htlcs_and_mark_paused had just been
 		// called but include holding cell updates (and obviously we don't modify self).
diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index c39eef3e..63466f9f 100644
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -3693,7 +3693,7 @@ impl Readable for HTLCForwardInfo {
 	}
 }
 
-impl<ChanSigner: ChannelKeys + Writeable, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable for ChannelManager<ChanSigner, M, T, K, F, L>
+impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable for ChannelManager<ChanSigner, M, T, K, F, L>
 	where M::Target: chain::Watch<Keys=ChanSigner>,
         T::Target: BroadcasterInterface,
         K::Target: KeysInterface<ChanKeySigner = ChanSigner>,
diff --git a/lightning/src/ln/onchaintx.rs b/lightning/src/ln/onchaintx.rs
index 146a4d57..513e4a13 100644
--- a/lightning/src/ln/onchaintx.rs
+++ b/lightning/src/ln/onchaintx.rs
@@ -286,7 +286,7 @@ pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
 	secp_ctx: Secp256k1<secp256k1::All>,
 }
 
-impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
+impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
 	pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 		self.destination_script.write(writer)?;
 		self.holder_commitment.write(writer)?;
-- 
2.30.2