Check for nil rw object in LogStore before attemting a sync

src/aof/engine.go

@@ -113,6 +113,12 @@ func NewAOFEngine(options ...func(engine *Engine)) *Engine {
 		handleCommand:     func(command []byte) {},
 	}
 
+	// Setup AOFEngine options first as these options are used
+	// when setting up the PreambleStore and AppendStore
+	for _, option := range options {
+		option(engine)
+	}
+
 	// Setup Preamble engine
 	engine.preambleStore = preamble.NewPreambleStore(
 		preamble.WithDirectory(engine.directory),
@@ -129,10 +135,6 @@ func NewAOFEngine(options ...func(engine *Engine)) *Engine {
 		logstore.WithHandleCommandFunc(engine.handleCommand),
 	)
 
-	for _, option := range options {
-		option(engine)
-	}
-
 	// 3. Start the goroutine to pick up queued commands in order to write them to the file.
 	// LogCommand will get the open file handler from the struct top perform the AOF operation.
 	go func() {

src/aof/log/store.go

@@ -73,9 +73,7 @@ func NewAppendStore(options ...func(store *AppendStore)) *AppendStore {
 		strategy:      "everysec",
 		rw:            nil,
 		mut:           sync.Mutex{},
-		handleCommand: func(command []byte) {
-			// No-Op
-		},
+		handleCommand: func(command []byte) {},
 	}
 
 	for _, option := range options {
@@ -130,9 +128,12 @@ func (store *AppendStore) Write(command []byte) error {
 
 func (store *AppendStore) Sync() error {
 	store.mut.Lock()
-	store.mut.Unlock()
+	defer store.mut.Unlock()
+	if store.rw != nil {
 		return store.rw.Sync()
 	}
+	return nil
+}
 
 func (store *AppendStore) Restore() error {
 	store.mut.Lock()