Fix EOF detection when reading an entire file

sdk/lib/io/file_impl.dart

 // Copyright (c) 2013, 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.
 
 part of dart.io;
 
 // Read the file in blocks of size 64k.
 const int _BLOCK_SIZE = 64 * 1024;
 
 
@@ skipping 428 matching lines @@
     var consumer = new _FileStreamConsumer(this, mode);
     return new IOSink(consumer, encoding: encoding);
   }
 
   Future<List<int>> readAsBytes() {
     Future<List<int>> readDataChunked(file) {
       var builder = new BytesBuilder(copy: false);
       var completer = new Completer();
       void read() {
         file.read(_BLOCK_SIZE).then((data) {
-          if (data.length > 0) builder.add(data);
-          if (data.length == _BLOCK_SIZE) {
+          if (data.length > 0) {
+            builder.add(data);
             read();
           } else {
             completer.complete(builder.takeBytes());
           }
         }, onError: completer.completeError);
       }
       read();
       return completer.future;
     }
 
@@ skipping 12 matching lines @@
     var opened = openSync();
     try {
       var data;
       var length = opened.lengthSync();
       if (length == 0) {
         // May be character device, try to read it in chunks.
         var builder = new BytesBuilder(copy: false);
         do {
           data = opened.readSync(_BLOCK_SIZE);
           if (data.length > 0) builder.add(data);
-        } while (data.length == _BLOCK_SIZE);
+        } while (data.length > 0);
         data = builder.takeBytes();
       } else {
         data = opened.readSync(length);
       }
       return data;
     } finally {
       opened.closeSync();
     }
   }
 
@@ skipping 525 matching lines @@
   void _checkAvailable() {
     if (_asyncDispatched) {
       throw new FileSystemException("An async operation is currently pending",
                                     path);
     }
     if (closed) {
       throw new FileSystemException("File closed", path);
     }
   }
 }