Reduce our stated max closing-transaction fee to be the true value

[rust-lightning] / lightning / src / ln / channel.rs

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index 0481a93fcd97e6fc566436dbbad9fad95f3d871c..767cf130db162f70c3e391eb2365120a89a3734a 100644 (file)
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -459,8 +459,8 @@ pub(super) struct Channel<Signer: Sign> {
        /// closing_signed message and handling it in `maybe_propose_closing_signed`.
        pending_counterparty_closing_signed: Option<msgs::ClosingSigned>,
 
-       /// The minimum and maximum absolute fee we are willing to place on the closing transaction.
-       /// These are set once we reach `closing_negotiation_ready`.
+       /// The minimum and maximum absolute fee, in satoshis, we are willing to place on the closing
+       /// transaction. These are set once we reach `closing_negotiation_ready`.
        #[cfg(test)]
        pub(crate) closing_fee_limits: Option<(u64, u64)>,
        #[cfg(not(test))]
@@ -3444,7 +3444,7 @@ impl<Signer: Sign> Channel<Signer> {
                                cmp::max(normal_feerate as u64 * tx_weight / 1000 + self.config.force_close_avoidance_max_fee_satoshis,
                                        proposed_max_feerate as u64 * tx_weight / 1000)
                        } else {
-                               u64::max_value()
+                               self.channel_value_satoshis - (self.value_to_self_msat + 999) / 1000
                        };
 
                self.closing_fee_limits = Some((proposed_total_fee_satoshis, proposed_max_total_fee_satoshis));
@@ -3732,7 +3732,8 @@ impl<Signer: Sign> Channel<Signer> {
 
                        if !self.is_outbound() {
                                // They have to pay, so pick the highest fee in the overlapping range.
-                               debug_assert_eq!(our_max_fee, u64::max_value()); // We should never set an upper bound
+                               // We should never set an upper bound aside from their full balance
+                               debug_assert_eq!(our_max_fee, self.channel_value_satoshis - (self.value_to_self_msat + 999) / 1000);
                                propose_fee!(cmp::min(max_fee_satoshis, our_max_fee));
                        } else {
                                if msg.fee_satoshis < our_min_fee || msg.fee_satoshis > our_max_fee {