From: Matt Corallo <git@bluematt.me>
Date: Sat, 8 Sep 2018 19:59:18 +0000 (-0400)
Subject: panic on invalid calls to Channel::send_commitment instead of Err
X-Git-Tag: v0.0.12~318^2
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=refs%2Fheads%2F2018-09-pre-disconnect-misc;p=rust-lightning

panic on invalid calls to Channel::send_commitment instead of Err
---

diff --git a/src/ln/channel.rs b/src/ln/channel.rs
index 77bd70143..d9633ea83 100644
--- a/src/ln/channel.rs
+++ b/src/ln/channel.rs
@@ -2390,12 +2390,13 @@ impl Channel {
 	/// Creates a signed commitment transaction to send to the remote peer.
 	/// Always returns a Channel-failing HandleError::action if an immediately-preceding (read: the
 	/// last call to this Channel) send_htlc returned Ok(Some(_)) and there is an Err.
+	/// May panic if called except immediately after a successful, Ok(Some(_))-returning send_htlc.
 	pub fn send_commitment(&mut self) -> Result<(msgs::CommitmentSigned, ChannelMonitor), HandleError> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
-			return Err(HandleError{err: "Cannot create commitment tx until channel is fully established", action: None});
+			panic!("Cannot create commitment tx until channel is fully established");
 		}
 		if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == (ChannelState::AwaitingRemoteRevoke as u32) {
-			return Err(HandleError{err: "Cannot create commitment tx until remote revokes their previous commitment", action: None});
+			panic!("Cannot create commitment tx until remote revokes their previous commitment");
 		}
 		let mut have_updates = false; // TODO initialize with "have we sent a fee update?"
 		for htlc in self.pending_htlcs.iter() {
@@ -2405,7 +2406,7 @@ impl Channel {
 			if have_updates { break; }
 		}
 		if !have_updates {
-			return Err(HandleError{err: "Cannot create commitment tx until we have some updates to send", action: None});
+			panic!("Cannot create commitment tx until we have some updates to send");
 		}
 		self.send_commitment_no_status_check()
 	}