Merge pull request #8377 from ellemouton/towerTestFlakeFix

wtclient: ensure correct disk mode for overflow queue

docs/release-notes/release-notes-0.18.0.md

@@ -49,7 +49,7 @@
   same exclusive group](https://github.com/lightningnetwork/lnd/pull/7800).
   When using neutrino as a backend unconfirmed transactions have to be
   removed from the wallet when a conflicting tx is confirmed. For other backends
-  these unconfirmed transactions are already removed. In addition a new 
+  these unconfirmed transactions are already removed. In addition, a new 
   walletrpc endpoint `RemoveTransaction` is introduced which let one easily
   remove unconfirmed transaction manually.
 
@@ -61,6 +61,9 @@
   this buffer which can be used to increase the commitment fee and it also
   protects against the case where htlcs are added asynchronously resulting in
   stuck channels.
+
+* [Fixed](https://github.com/lightningnetwork/lnd/pull/8377) a watchtower client
+  test flake that prevented new tasks from overflowing to disk. 
 
 * [Properly handle un-acked updates for exhausted watchtower 
   sessions](https://github.com/lightningnetwork/lnd/pull/8233)

watchtower/wtclient/queue.go

@@ -476,6 +476,13 @@ func (q *DiskOverflowQueue[T]) feedMemQueue() {
 				}
 			}
 
+			// If we did manage to fetch a task from disk, we make
+			// sure to set the toDisk mode to true since we may
+			// block indefinitely while trying to push the tasks to
+			// the memQueue in which case we want the drainInputList
+			// goroutine to write any new tasks to disk.
+			q.toDisk.Store(true)
+
 			for i, task := range tasks {
 				select {
 				case q.memQueue <- task: