Fix clipboard history lock recovery and merged selection

internal/clipboard/shared_history.go

@@ -134,6 +134,7 @@ func (p *Persistence) run(path string, watching bool) {
 	defer tick.Stop()
 	last := HistoryUpdate{State: p.Initial, Enabled: p.InitialEnabled}
 	var signature string
+	var retryLock bool
 	var acknowledged uint64
 	for {
 		select {
@@ -167,7 +168,7 @@ func (p *Persistence) run(path string, watching bool) {
 			continue
 		}
 		nextSignature := history_signature(path)
-		if nextSignature == signature {
+		if nextSignature == signature && !retryLock {
 			continue
 		}
 		file, err := acquire_history(path, false)
@@ -182,16 +183,21 @@ func (p *Persistence) run(path string, watching bool) {
 			}
 		}
 		if err != nil {
-			// Report a stable failure once, and retry after a file changes.
+			// Report a stable failure once. Lock contention can clear without
+			// changing either file, so it must also be retried on the next tick.
 			if signature != nextSignature {
 				p.report(err)
 			}
 		} else {
+			if retryLock {
+				p.report(nil)
+			}
 			if !reflect.DeepEqual(update, last) {
 				p.publish(update)
 				last = update
 			}
 		}
+		retryLock = errors.Is(err, syscall.EWOULDBLOCK)
 		signature = nextSignature
 	}
 }
@@ -294,6 +300,7 @@ func apply_history(path string, job historyJob) (HistoryUpdate, error) {
 				}
 				if !found {
 					state.Entries = append([]string{text}, state.Entries...)
+					state.Selected++
 				}
 			}
 		}