Close file watcher when target is deleted.

runtime/bin/file_patch.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 patch class _File {
   /* patch */ static _exists(String path) native "File_Exists";
   /* patch */ static _create(String path) native "File_Create";
   /* patch */ static _createLink(String path, String target)
       native "File_CreateLink";
   /* patch */ static _linkTarget(String path) native "File_LinkTarget";
@@ skipping 58 matching lines @@
     try {
       socketId = _watchPath(_path, _events, identical(true, _recursive));
     } catch (e) {
       throw new FileException(
           "Failed to watch path",
           _path,
           e);
     }
     var socket = new _RawSocket(new _NativeSocket.watch(socketId));
     _subscription = socket.expand((event) {
+      bool stop = false;
       var events = [];
       var pair = {};
       if (event == RawSocketEvent.READ) {
         String getPath(event) {
           var path = _path;
           if (event[2] != null) {
             path += Platform.pathSeparator;
             path += event[2];
           }
           return path;
         }
+        void add(event) {
+          if ((event.type & _events) == 0) return;
+          events.add(event);
+        }
         while (socket.available() > 0) {
           for (var event in _readEvents()) {
             if (event == null) continue;
             var path = getPath(event);
             if ((event[0] & FileSystemEvent.CREATE) != 0) {
-              events.add(new FileSystemCreateEvent._(path));
+              add(new FileSystemCreateEvent._(path));
             }
             if ((event[0] & FileSystemEvent.MODIFY) != 0) {
-              events.add(new FileSystemModifyEvent._(path, true));
+              add(new FileSystemModifyEvent._(path, true));
             }
             if ((event[0] & FileSystemEvent._MODIFY_ATTRIBUTES) != 0) {
-              events.add(new FileSystemModifyEvent._(path, false));
+              add(new FileSystemModifyEvent._(path, false));
             }
             if ((event[0] & FileSystemEvent.MOVE) != 0) {
               int link = event[1];
               if (link > 0) {
                 if (pair.containsKey(link)) {
                   events.add(
                       new FileSystemMoveEvent._(getPath(pair[link]), path));
                   pair.remove(link);
                 } else {
                   pair[link] = event;
                 }
               } else {
-                events.add(new FileSystemMoveEvent._(path, null));
+                add(new FileSystemMoveEvent._(path, null));
               }
             }
             if ((event[0] & FileSystemEvent.DELETE) != 0) {
-              events.add(new FileSystemDeleteEvent._(path));
+              add(new FileSystemDeleteEvent._(path));
+            }
+            if ((event[0] & FileSystemEvent._DELETE_SELF) != 0) {
+              add(new FileSystemDeleteEvent._(path));
+              stop = true;
             }
           }
         }
         for (var event in pair.values) {
           events.add(new FileSystemMoveEvent._(getPath(event), null));
         }
       } else if (event == RawSocketEvent.CLOSED) {
       } else if (event == RawSocketEvent.READ_CLOSED) {
       } else {
         assert(false);
       }
+      if (stop) socket.close();
       return events;
     })
-    .where((event) => (event.type & _events) != 0)
     .listen(_controller.add, onDone: _cancel);
   }
 
   void _cancel() {
     _unwatchPath();
     if (_subscription != null) {
       _subscription.cancel();
     }
+    _controller.close();
   }
 
   Stream<FileSystemEvent> get stream => _controller.stream;
 
   static bool get isSupported native "FileSystemWatcher_IsSupported";
 
   int _watchPath(String path, int events, bool recursive)
       native "FileSystemWatcher_WatchPath";
   void _unwatchPath() native "FileSystemWatcher_UnwatchPath";
   List _readEvents() native "FileSystemWatcher_ReadEvents";
 }
 
 Uint8List _makeUint8ListView(Uint8List source, int offsetInBytes, int length) {
   return new Uint8List.view(source.buffer, offsetInBytes, length);
 }