Preserve watch flags when watching for delete

Fixes issue where adding a watch for a directory assumed that all
subdirectories can be watched for only delete. They should, but if they
are already watched we need to preserve the flags already set and add
delete watch.

Issue #21

diff --git a/fsnotify_bsd.go b/fsnotify_bsd.go
index edafb99bb2f76c12321c06597df8ac0c0550c07a..0dc7bad39bf09110b2d898bd7786dfaeb607d5c0 100644 (file)
--- a/fsnotify_bsd.go
+++ b/fsnotify_bsd.go
@@ -40,6 +40,7 @@ type Watcher struct {
        kq            int                 // File descriptor (as returned by the kqueue() syscall)
        watches       map[string]int      // Map of watched file diescriptors (key: path)
        fsnFlags      map[string]uint32   // Map of watched files to flags used for filter
+       enFlags       map[string]uint32   // Map of watched files to evfilt note flags used in kqueue
        paths         map[int]string      // Map of watched paths (key: watch descriptor)
        finfo         map[int]os.FileInfo // Map of file information (isDir, isReg; key: watch descriptor)
        fileExists    map[string]bool     // Keep track of if we know this file exists (to stop duplicate create events)
@@ -61,6 +62,7 @@ func NewWatcher() (*Watcher, error) {
                kq:            fd,
                watches:       make(map[string]int),
                fsnFlags:      make(map[string]uint32),
+               enFlags:       make(map[string]uint32),
                paths:         make(map[int]string),
                finfo:         make(map[int]os.FileInfo),
                fileExists:    make(map[string]bool),
@@ -140,11 +142,12 @@ func (w *Watcher) addWatch(path string, flags uint32) error {
 
                w.finfo[watchfd] = fi
        }
-       
+
        if w.finfo[watchfd].IsDir() && (flags&NOTE_WRITE) == NOTE_WRITE {
                watchDir = true
        }
 
+       w.enFlags[path] = watchEntry.Fflags
        syscall.SetKevent(watchEntry, watchfd, syscall.EVFILT_VNODE, syscall.EV_ADD|syscall.EV_CLEAR)
 
        wd, errno := syscall.Kevent(w.kq, w.kbuf[:], nil, nil)
@@ -285,8 +288,16 @@ func (w *Watcher) watchDirectoryFiles(dirPath string) error {
                                return e
                        }
                } else {
+                       // If the user is currently waching directory
+                       // we want to preserve the flags used
+                       currFlags, found := w.enFlags[filePath]
+                       var newFlags uint32 = NOTE_DELETE
+                       if found {
+                               newFlags |= currFlags
+                       }
+
                        // Linux gives deletes if not explicitly watching
-                       e := w.addWatch(filePath, NOTE_DELETE)
+                       e := w.addWatch(filePath, newFlags)
                        w.fsnFlags[filePath] = FSN_ALL
                        if e != nil {
                                return e