Watch the *directory* for file deletions instead of the file itself.

inotify works on the inode, not the path.  Deleting the file doesn't
touch the inode, so doesn't generate an event on the file.

Fixes #57

watch/inotify.go

@@ -59,15 +59,22 @@ func (fw *InotifyFileWatcher) BlockUntilExists(t *tomb.Tomb) error {
 func (fw *InotifyFileWatcher) ChangeEvents(t *tomb.Tomb, fi os.FileInfo) *FileChanges {
 	changes := NewFileChanges()
 
-	err := fw.w.Watch(fw.Filename)
-	if err != nil {
+	if err := fw.w.Watch(fw.Filename); err != nil {
 		util.Fatal("Error watching %v: %v", fw.Filename, err)
 	}
 
+	// Watch the directory to be notified when the file is deleted since the file
+	// watch is on the inode, not the path.
+	dirname := filepath.Dir(fw.Filename)
+	if err := fw.w.WatchFlags(dirname, fsnotify.FSN_DELETE); err != nil {
+		util.Fatal("Error watching %v: %v", dirname, err)
+	}
+
 	fw.Size = fi.Size()
 
 	go func() {
 		defer fw.w.RemoveWatch(fw.Filename)
+		defer fw.w.RemoveWatch(dirname)
 		defer changes.Close()
 
 		for {
@@ -87,6 +94,9 @@ func (fw *InotifyFileWatcher) ChangeEvents(t *tomb.Tomb, fi os.FileInfo) *FileCh
 
 			switch {
 			case evt.IsDelete():
+				if filepath.Base(evt.Name) != filepath.Base(fw.Filename) {
+					continue
+				}
 				fallthrough
 
 			case evt.IsRename():