Fix some type and logical errors in test.dart, found by the Dart editor.

tools/testing/dart/multitest.dart

 // Copyright (c) 2011, 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.
 
 #library("multitest");
 
 #import("dart:io");
 #import("test_suite.dart");
 
 // Multitests are Dart test scripts containing lines of the form
@@ skipping 39 matching lines @@
 //   aaa
 //   ddd /// 07: static type warning, dynamic type error
 //   eee
 
 void ExtractTestsFromMultitest(String filename,
                                Map<String, String> tests,
                                Map<String, Set<String>> outcomes) {
   // Read the entire file into a byte buffer and transform it to a
   // String. This will treat the file as ascii but the only parts
   // we are interested in will be ascii in any case.
-  RandomAccessFile file = (new File(filename)).openSync();
+  RandomAccessFile file = (new File(filename)).openSync(FileMode.READ);
   List chars = new List(file.lengthSync());
   int offset = 0;
   while (offset != chars.length) {
     offset += file.readListSync(chars, offset, chars.length - offset);
   }
   file.closeSync();
   String contents = new String.fromCharCodes(chars);
   chars = null;
   int first_newline = contents.indexOf('\n');
   final String line_separator =
@@ skipping 94 matching lines @@
 void DoMultitest(String filename,
                  String outputDir,
                  String testDir,
                  // TODO(zundel): Are the boolean flags now redundant
                  // with the 'multitestOutcome' field?
                  Function doTest(String filename,
                                  bool isNegative,
                                  [bool isNegativeIfChecked,
                                   bool hasFatalTypeErrors,
                                   bool hasRuntimeErrors,
-                                  String multitestOutcome]),
+                                  Set<String> multitestOutcome]),
                  Function multitestDone) {
   // Each new test is a single String value in the Map tests.
   Map<String, String> tests = new Map<String, String>();
   Map<String, Set<String>> outcomes = new Map<String, Set<String>>();
   ExtractTestsFromMultitest(filename, tests, outcomes);
 
   String directory = CreateMultitestDirectory(outputDir, testDir);
   Expect.isNotNull(directory);
   String pathSep = new Platform().pathSeparator();
   int start = filename.lastIndexOf(pathSep) + 1;
   int end = filename.indexOf('.dart', start);
   String baseFilename = filename.substring(start, end);
   String sourceDirectory = filename.substring(0, start - 1);
   Set<String> importsToCopy = _findAllRelativeImports(filename);
   Directory destDir = new Directory("directory");
   for (String import in importsToCopy) {
     File source = new File('$sourceDirectory/$import');
     var dest = new File('$directory/$import');
     var basenameStart = import.lastIndexOf('/');
     if (basenameStart > 0) {
       // make sure we have a dir for it
       var importDir = import.substring(0, basenameStart);
       TestUtils.mkdirRecursive(directory, importDir);
     }
     TestUtils.copyFile(source, dest);
   }
   for (String key in tests.getKeys()) {
-    final String filename = '$directory/${baseFilename}_$key.dart';
-    final File file = new File(filename);
+    final String multitestFilename = '$directory/${baseFilename}_$key.dart';
+    final File file = new File(multitestFilename);
 
     file.createSync();
     RandomAccessFile openedFile = file.openSync(FileMode.WRITE);
     var bytes = tests[key].charCodes();
     openedFile.writeListSync(bytes, 0, bytes.length);
     openedFile.closeSync();
     Set<String> outcome = outcomes[key];
     bool enableFatalTypeErrors = outcome.contains('static type warning');
     bool hasRuntimeErrors = outcome.contains('runtime error');
     bool isNegative = hasRuntimeErrors
         || outcome.contains('compile-time error');
     bool isNegativeIfChecked = outcome.contains('dynamic type error');
-    doTest(filename,
+    doTest(multitestFilename,
            isNegative,
            isNegativeIfChecked,
            enableFatalTypeErrors,
            hasRuntimeErrors,
            outcome);
   }
   multitestDone();
 }
 
 
 String CreateMultitestDirectory(String outputDir, String testDir) {
   final String generatedTestDirectory = 'generated_tests';
   Directory generatedTestDir = new Directory('$outputDir/generated_tests');
   if (!new Directory(outputDir).existsSync()) {
     new Directory(outputDir).createSync();
   }
   if (!generatedTestDir.existsSync()) {
     generatedTestDir.createSync();
   }
   var split = testDir.split('/');
   var lastComponent = split.removeLast();
   Expect.isTrue(lastComponent == 'src');
   String path = '${generatedTestDir.path}/${split.last()}';
   Directory dir = new Directory(path);
   if (!dir.existsSync()) {
     dir.createSync();
   }
   return path;
 }