fixes #219, able to compile multiple entry points

lib/src/summary.dart

 // Copyright (c) 2015, 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.
 
 /// Summary of error messages produced by a `SummaryReporter`.
 library dev_compiler.src.summary;
 
 import 'dart:collection' show HashSet;
 import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
 import 'package:analyzer/src/generated/source.dart' show Source;
@@ skipping 86 matching lines @@
   /// All messages collected for the library.
   final List<MessageSummary> messages;
 
   /// All parts of this library. Only used for computing _lines.
   final _uris = new HashSet<Uri>();
 
   int _lines;
 
   LibrarySummary(this.name, {List<MessageSummary> messages, lines})
       : messages = messages == null ? <MessageSummary>[] : messages,
-        _lines = lines == null ? lines : 0;

[vsm, 2015/07/16 23:56:39]

oops!

+        _lines = lines != null ? lines : 0;
 
   void clear() {
     _uris.clear();
     _lines = 0;
     messages.clear();
   }
 
   /// Total lines of code (including all parts of the library).
   int get lines => _lines;
 
@@ skipping 123 matching lines @@
     }
   }
 
   void visitHtml(HtmlSummary html) {
     for (var msg in html.messages) {
       msg.accept(this);
     }
   }
   void visitMessage(MessageSummary message) {}
 }