maildir: watch for external changes

When a maildir is synchronized by an external process while aerc is
running (e.g. mbsync), some emails may be moved out of "new" to "cur" or
completely deleted.

These deletions are ignored and aerc may assume these messages are still
here, leading to errors.

Take file deletions into account. Also, add "cur" to the watched
folders since these can be modified as well.

Signed-off-by: Robin Jarry <robin@jarry.cc>

1 files changed, 12 insertions, 4 deletions

diff --git a/worker/maildir/worker.go b/worker/maildir/worker.go
index 5888f114..099a85c1 100644
--- a/worker/maildir/worker.go
+++ b/worker/maildir/worker.go
@@ -71,8 +71,8 @@ func (w *Worker) handleAction(action types.WorkerMessage) {
 }
 
 func (w *Worker) handleFSEvent(ev fsnotify.Event) {
-	// we only care about files being created
-	if ev.Op != fsnotify.Create {
+	// we only care about files being created or removed
+	if ev.Op != fsnotify.Create && ev.Op != fsnotify.Remove {
 		return
 	}
 	// if there's not a selected directory to rescan, ignore
@@ -275,22 +275,30 @@ func (w *Worker) handleOpenDirectory(msg *types.OpenDirectory) error {
 		return err
 	}
 
-	// remove existing watch path
+	// remove existing watch paths
 	if w.selected != nil {
 		prevDir := filepath.Join(string(*w.selected), "new")
 		if err := w.watcher.Remove(prevDir); err != nil {
 			return fmt.Errorf("could not unwatch previous directory: %v", err)
 		}
+		prevDir = filepath.Join(string(*w.selected), "cur")
+		if err := w.watcher.Remove(prevDir); err != nil {
+			return fmt.Errorf("could not unwatch previous directory: %v", err)
+		}
 	}
 
 	w.selected = &dir
 	w.selectedName = msg.Directory
 
-	// add watch path
+	// add watch paths
 	newDir := filepath.Join(string(*w.selected), "new")
 	if err := w.watcher.Add(newDir); err != nil {
 		return fmt.Errorf("could not add watch to directory: %v", err)
 	}
+	newDir = filepath.Join(string(*w.selected), "cur")
+	if err := w.watcher.Add(newDir); err != nil {
+		return fmt.Errorf("could not add watch to directory: %v", err)
+	}
 
 	if err := dir.Clean(); err != nil {
 		return fmt.Errorf("could not clean directory: %v", err)