Fix broken test of platform version

tests/standalone/io/platform_test.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.
 
 import "dart:async";
 import "dart:io";
 import "dart:isolate";
 
 import "package:async_helper/async_helper.dart";
 import "package:expect/expect.dart";
@@ skipping 68 matching lines @@
     // Patch version.
     Expect.isTrue(int.parse(match.group(3)) >= 0);
     // Dev
     if (match.group(4) != null) {
       // Dev prerelease minor version
       Expect.isTrue(int.parse(match.group(5)) >= 0);
       // Dev prerelease patch version
       Expect.isTrue(int.parse(match.group(6)) >= 0);
     }
   }
+
+  String stripAdditionalInfo(String version) {
+    var index = version.indexOf(' ');
+    if (index == -1) return version;
+    return version.substring(0, index);
+  }
+
   // Ensure we can match valid versions.
   checkValidVersion('1.9.0');
   checkValidVersion('1.9.0-dev.0.0');
   checkValidVersion('1.9.0-edge');
   checkValidVersion('1.9.0-edge.r41234');
+  // Check stripping of additional information.
+  checkValidVersion(stripAdditionalInfo(
+      '1.9.0-dev.1.2 (Wed Feb 25 02:22:19 2015) on "linux_ia32"'));
   // Test current version.
-  checkValidVersion(Platform.version);
+  checkValidVersion(stripAdditionalInfo(Platform.version));
   // Test some invalid versions.
   Expect.throws(() => checkValidVersion('1.9'));
   Expect.throws(() => checkValidVersion('2.0.0'));
   Expect.throws(() => checkValidVersion('..'));
   Expect.throws(() => checkValidVersion('1..'));
   Expect.throws(() => checkValidVersion('1.9.'));
   Expect.throws(() => checkValidVersion('1.9.0-dev..'));
   Expect.throws(() => checkValidVersion('1.9.0-dev..0'));
   Expect.throws(() => checkValidVersion('1.9.0-dev.0.'));
   Expect.throws(() => checkValidVersion('1.9.0-dev.x.y'));
   Expect.throws(() => checkValidVersion('x'));
   Expect.throws(() => checkValidVersion('x.y.z'));
 }
 
 main() {
   // This tests assumes paths relative to dart main directory
   Directory.current = Platform.script.resolve('../../..').toFilePath();
   test();
   testIsolate();
   testVersion();
 }