Fix a lockfile freshness checking bug.

test/must_pub_get_test.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.
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:path/path.dart' as p;
 import 'package:pub/src/exit_codes.dart' as exit_codes;
 import 'package:pub/src/io.dart';
@@ skipping 275 matching lines @@
           "SDK constraints. Please run \"pub get\" again.");
     });
 
     group("a path dependency's dependency doesn't match the lockfile", () {
       setUp(() {
         d.dir("bar", [
           d.libPubspec("bar", "1.0.0", deps: {"foo": "1.0.0"})
         ]).create();
 
         d.dir(appPath, [
-          d.appPubspec({"foo": {"path": "../foo"}})
-        ]);
+          d.appPubspec({"bar": {"path": "../bar"}})
+        ]).create();
 
         pubGet();
 
-        // Update foo's pubspec without touching the app's.
+        // Update bar's pubspec without touching the app's.
         d.dir("bar", [
           d.libPubspec("bar", "1.0.0", deps: {"foo": "2.0.0"})
         ]).create();
       });
+
+      _requiresPubGet('${p.join('..', 'bar', 'pubspec.yaml')} has changed '
+          'since the pubspec.lock file was generated, please run "pub get" '
+          'again.');
     });
   });
 
   group("doesn't require the user to run pub get first if", () {
     group("the pubspec is older than the lockfile which is older than the "
         "packages file, even if the contents are wrong", () {
       setUp(() {
         d.dir(appPath, [
           d.appPubspec({"foo": "1.0.0"})
         ]).create();
@@ skipping 96 matching lines @@
 void _touch(String path) {
   schedule(() async {
     // Delay a bit to make sure the modification times are noticeably different.
     // 1s seems to be the finest granularity that dart:io reports.
     await new Future.delayed(new Duration(seconds: 1));
 
     path = p.join(sandboxDir, "myapp", path);
     touch(path);
   }, "touching $path");
 }