Handle errors when waiting for subscriptions

We were not thorough enough in PR #705 and there were some remaining
unhandled errors.

Co-authored-by: Daniel Karzel <daniel@comit.network>

CHANGELOG.md

@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- A bug where the ASB erroneously transitioned into a punishable state upon a bitcoin transaction monitoring error.
+  This could lead to a scenario where the ASB was neither able to punish, nor able to refund, so the XMR could stay locked up forever while the CLI refunded the BTC.
+- A bug where the CLI erroneously transitioned into a cancel-timelock-expired state upon a bitcoin transaction monitoring error.
+  This could lead to a scenario where the CLI is forced to wait for cancel, even though the cancel timelock is not yet expired and the swap could still be redeemed.
+
 ## [0.8.2] - 2021-09-01
 
 ### Added

swap/src/protocol/alice/swap.rs

@@ -176,7 +176,8 @@ where
                        state3,
                    }
                 },
-                _ = tx_lock_status.wait_until_confirmed_with(state3.cancel_timelock) => {
+                result = tx_lock_status.wait_until_confirmed_with(state3.cancel_timelock) => {
+                    let _ = result?;
                     AliceState::CancelTimelockExpired {
                         monero_wallet_restore_blockheight,
                         transfer_proof,
@@ -325,7 +326,9 @@ where
                         state3,
                     }
                 }
-                _ = tx_cancel_status.wait_until_confirmed_with(state3.punish_timelock) => {
+                result = tx_cancel_status.wait_until_confirmed_with(state3.punish_timelock) => {
+                    let _ = result?;
+
                     AliceState::BtcPunishable {
                         monero_wallet_restore_blockheight,
                         transfer_proof,

swap/src/protocol/bob/swap.rs

@@ -123,7 +123,8 @@ async fn next_state(
                             monero_wallet_restore_blockheight
                         }
                     },
-                    _ = cancel_timelock_expires => {
+                    result = cancel_timelock_expires => {
+                        let _ = result?;
                         tracing::info!("Alice took too long to lock Monero, cancelling the swap");
 
                         let state4 = state3.cancel();