From: Matt Corallo <git@bluematt.me>
Date: Fri, 24 Aug 2018 15:52:55 +0000 (-0400)
Subject: Fix crash introduced in #124
X-Git-Tag: v0.0.12~339^2~1
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=4f77c812a4b0e42454cb92b8b460dfa1323016cb;p=rust-lightning

Fix crash introduced in #124

I'm rapidly starting to regret holding failed HTLCs in Channel,
given we allow them to violate the no-duplicate-hashes
precondition.

Found by fuzzer
---

diff --git a/src/ln/channel.rs b/src/ln/channel.rs
index 47c05de2..d6e23a28 100644
--- a/src/ln/channel.rs
+++ b/src/ln/channel.rs
@@ -1018,10 +1018,13 @@ impl Channel {
 		for (idx, htlc) in self.pending_htlcs.iter().enumerate() {
 			if !htlc.outbound && htlc.payment_hash == payment_hash_calc &&
 					htlc.state != HTLCState::LocalRemoved && htlc.state != HTLCState::LocalRemovedAwaitingCommitment {
-				if pending_idx != std::usize::MAX {
-					panic!("Duplicate HTLC payment_hash, ChannelManager should have prevented this!");
+				if let Some(PendingHTLCStatus::Fail(_)) = htlc.pending_forward_state {
+				} else {
+					if pending_idx != std::usize::MAX {
+						panic!("Duplicate HTLC payment_hash, ChannelManager should have prevented this!");
+					}
+					pending_idx = idx;
 				}
-				pending_idx = idx;
 			}
 		}
 		if pending_idx == std::usize::MAX {