Implement From<InboundV1Channel> for ChannelPhase

Exposing ChannelPhase in ChannelManager has led to verbose match
statements, which need to be modified each time a ChannelPhase is added.
Making ChannelPhase an implementation detail of Channel would help avoid
this.

As a step in this direction, define a conversion from InboundV1Channel
to ChannelPhase (to be renamed Channel).

Author: jkczyz

lightning/src/ln/channel.rs

@@ -1368,6 +1368,16 @@ where
 	}
 }
 
+impl<SP: Deref> From<InboundV1Channel<SP>> for ChannelPhase<SP>
+where
+	SP::Target: SignerProvider,
+	<SP::Target as SignerProvider>::EcdsaSigner: ChannelSigner,
+{
+	fn from(channel: InboundV1Channel<SP>) -> Self {
+		ChannelPhase::UnfundedInboundV1(channel)
+	}
+}
+
 impl<SP: Deref> From<Channel<SP>> for ChannelPhase<SP>
 where
 	SP::Target: SignerProvider,

lightning/src/ln/channelmanager.rs

@@ -7689,7 +7689,7 @@ This indicates a bug inside LDK. Please report this error at https://github.com/
 									msg,
 								}
 							});
-							(*temporary_channel_id, ChannelPhase::UnfundedInboundV1(channel), message_send_event)
+							(*temporary_channel_id, ChannelPhase::from(channel), message_send_event)
 						})
 					},
 					#[cfg(dual_funding)]
@@ -7977,7 +7977,7 @@ This indicates a bug inside LDK. Please report this error at https://github.com/
 						msg,
 					}
 				});
-				(ChannelPhase::UnfundedInboundV1(channel), message_send_event)
+				(ChannelPhase::from(channel), message_send_event)
 			},
 			#[cfg(dual_funding)]
 			OpenChannelMessageRef::V2(msg) => {