Fix fuzztarget failures

src/ln/channelmanager.rs

@@ -365,9 +365,15 @@ impl ChannelManager {
 		let channel = Channel::new_outbound(&*self.fee_estimator, chan_keys, their_network_key, channel_value_satoshis, push_msat, self.announce_channels_publicly, user_id, Arc::clone(&self.logger))?;
 		let res = channel.get_open_channel(self.genesis_hash.clone(), &*self.fee_estimator);
 		let mut channel_state = self.channel_state.lock().unwrap();
-		match channel_state.by_id.insert(channel.channel_id(), channel) {
-			Some(_) => panic!("RNG is bad???"),
-			None => {}
+		match channel_state.by_id.entry(channel.channel_id()) {
+			hash_map::Entry::Occupied(_) => {
+				if cfg!(feature = "fuzztarget") {
+					return Err(APIError::APIMisuseError { err: "Fuzzy bad RNG" });
+				} else {
+					panic!("RNG is bad???");
+				}
+			},
+			hash_map::Entry::Vacant(entry) => { entry.insert(channel); }
 		}
 
 		let mut events = self.pending_events.lock().unwrap();
@@ -2456,9 +2462,11 @@ mod tests {
 	}
 	impl Drop for Node {
 		fn drop(&mut self) {
-			// Check that we processed all pending events
-			assert_eq!(self.node.get_and_clear_pending_events().len(), 0);
-			assert_eq!(self.chan_monitor.added_monitors.lock().unwrap().len(), 0);
+			if !::std::thread::panicking() {
+				// Check that we processed all pending events
+				assert_eq!(self.node.get_and_clear_pending_events().len(), 0);
+				assert_eq!(self.chan_monitor.added_monitors.lock().unwrap().len(), 0);
+			}
 		}
 	}
 

src/ln/channelmonitor.rs

@@ -1011,7 +1011,9 @@ impl ChannelMonitor {
 
 	/// Attempst to claim a remote HTLC-Success/HTLC-Timeout s outputs using the revocation key
 	fn check_spend_remote_htlc(&self, tx: &Transaction, commitment_number: u64) -> Option<Transaction> {
-		let htlc_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
+		if tx.input.len() != 1 || tx.output.len() != 1 {
+			return None;
+		}
 
 		macro_rules! ignore_error {
 			( $thing : expr ) => {
@@ -1039,6 +1041,7 @@ impl ChannelMonitor {
 		};
 		let redeemscript = chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.their_to_self_delay.unwrap(), &delayed_key);
 		let revokeable_p2wsh = redeemscript.to_v0_p2wsh();
+		let htlc_txid = tx.txid(); //TODO: This is gonna be a performance bottleneck for watchtowers!
 
 		let mut inputs = Vec::new();
 		let mut amount = 0;