notmuch: move logic for dynamic folders to backend

Moves logic for creating dynamic folders from the dirlist widget to the
backend. Since dynamic folders are notmuch-specific, the notmuch backend
should be responsible for correctly setting up those folders. It does
that by sending two DirectoryInfos: the first to create the message
store, the second to fetch the directory content.

This approach also fixes a deadlock introduced by 716ade8968
("worker: lock access to callback maps").

Reported-by: Bence Ferdinandy <bence@ferdinandy.com>
Signed-off-by: Koni Marti <koni.marti@gmail.com>
Tested-by: Tim Culverhouse <tim@timculverhouse.com>

widgets/dirlist.go

@@ -156,12 +156,6 @@ func (dirlist *DirectoryList) Select(name string) {
 
 		select {
 		case <-time.After(delay):
-			newStore := true
-			for _, s := range dirlist.store.List() {
-				if s == dirlist.selecting {
-					newStore = false
-				}
-			}
 			dirlist.worker.PostAction(&types.OpenDirectory{Directory: name},
 				func(msg types.WorkerMessage) {
 					switch msg.(type) {
@@ -185,13 +179,6 @@ func (dirlist *DirectoryList) Select(name string) {
 							sort.Strings(dirlist.dirs)
 						}
 						dirlist.sortDirsByFoldersSortConfig()
-						if newStore {
-							store, ok := dirlist.MsgStore(name)
-							if ok {
-								// Fetch directory contents via store.Sort
-								store.Sort(nil, nil)
-							}
-						}
 					}
 					dirlist.Invalidate()
 				})

worker/notmuch/worker.go

@@ -249,7 +249,7 @@ func (w *worker) buildDirInfo(name string, query string, skipSort bool) (
 }
 
 func (w *worker) emitDirectoryInfo(name string) error {
-	query := w.queryFromName(name)
+	query, _ := w.queryFromName(name)
 	info, err := w.gatherDirectoryInfo(name, query)
 	if err != nil {
 		return err
@@ -260,19 +260,20 @@ func (w *worker) emitDirectoryInfo(name string) error {
 
 // queryFromName either returns the friendly ID if aliased or the name itself
 // assuming it to be the query
-func (w *worker) queryFromName(name string) string {
+func (w *worker) queryFromName(name string) (string, bool) {
 	// try the friendly name first, if that fails assume it's a query
 	q, ok := w.nameQueryMap[name]
 	if !ok {
-		return name
+		return name, true
 	}
-	return q
+	return q, false
 }
 
 func (w *worker) handleOpenDirectory(msg *types.OpenDirectory) error {
 	logging.Infof("opening %s", msg.Directory)
 	// try the friendly name first, if that fails assume it's a query
-	w.query = w.queryFromName(msg.Directory)
+	var isQuery bool
+	w.query, isQuery = w.queryFromName(msg.Directory)
 	w.currentQueryName = msg.Directory
 	info, err := w.gatherDirectoryInfo(msg.Directory, w.query)
 	if err != nil {
@@ -280,6 +281,9 @@ func (w *worker) handleOpenDirectory(msg *types.OpenDirectory) error {
 	}
 	info.Message = types.RespondTo(msg)
 	w.w.PostMessage(info, nil)
+	if isQuery {
+		w.w.PostMessage(info, nil)
+	}
 	w.done(msg)
 	return nil
 }