msgstore: do not trigger notification on initial load

There currently is no difference between updating the store of
a directory that was already loaded, and a directory that has not yet
been initialized. When a directory is opened, and the initial update
request is processed, all messages are therefore treated as new, and the
directory change notification (i.e. bell) is triggered.

To prevent triggering this update, track whether the directory was
already initialized, and if not, don't send out any change
notifications.

Signed-off-by: Remko Tronçon <remko@el-tramo.be>
Acked-by: Robin Jarry <robin@jarry.cc>

lib/msgstore.go

@@ -56,6 +56,8 @@ type MessageStore struct {
 	buildThreads  bool
 	builder       *ThreadBuilder
 
+	directoryContentsLoaded bool
+
 	// Map of uids we've asked the worker to fetch
 	onUpdate       func(store *MessageStore) // TODO: multiple onUpdate handlers
 	onFilterChange func(store *MessageStore)
@@ -256,6 +258,7 @@ func (store *MessageStore) Update(msg types.WorkerMessage) {
 	update := false
 	updateThreads := false
 	directoryChange := false
+	directoryContentsWasLoaded := store.directoryContentsLoaded
 	start := store.scrollOffset
 	end := store.scrollOffset + store.scrollLen
 
@@ -281,6 +284,7 @@ func (store *MessageStore) Update(msg types.WorkerMessage) {
 		if store.threadedView {
 			store.runThreadBuilderNow()
 		}
+		store.directoryContentsLoaded = true
 	case *types.DirectoryThreaded:
 		if store.builder == nil {
 			store.builder = NewThreadBuilder(store.iterFactory,
@@ -392,13 +396,13 @@ func (store *MessageStore) Update(msg types.WorkerMessage) {
 		store.update(updateThreads)
 	}
 
-	if directoryChange && store.triggerDirectoryChange != nil {
+	if directoryContentsWasLoaded && directoryChange && store.triggerDirectoryChange != nil {
 		store.triggerDirectoryChange()
 	}
 
 	if len(newUids) > 0 {
 		store.FetchHeaders(newUids, nil)
-		if store.triggerDirectoryChange != nil {
+		if directoryContentsWasLoaded && store.triggerDirectoryChange != nil {
 			store.triggerDirectoryChange()
 		}
 	}