Start auto-close timer at outbound update fee failure.

Author: Antoine Riard

lightning/src/ln/channel.rs

@@ -3173,7 +3173,10 @@ impl<Signer: Sign> Channel<Signer> {
 		let buffer_fee_msat = Channel::<Signer>::commit_tx_fee_sat(feerate_per_kw, commitment_stats.num_nondust_htlcs + outbound_stats.on_holder_tx_holding_cell_htlcs_count as usize + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize) * 1000;
 		let holder_balance_msat = commitment_stats.local_balance_msat - outbound_stats.holding_cell_msat;
 		if holder_balance_msat < buffer_fee_msat  + self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 {
-			//TODO: auto-close after a number of failures?
+			// If we're failing affordance, start a autoclose timer as the situation is
+			// likely unsafe due to a heavy-loaded channel, of which the feerate should
+			// become less and less compelling.
+			self.maybe_trigger_autoclose_timer(self.get_feerate(), feerate_per_kw, background_feerate);
 			log_debug!(logger, "Cannot afford to send new feerate at {}", feerate_per_kw);
 			return None;
 		}