Tolerate null from finding browser locale, re-enable tests

pkg/intl/lib/intl.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.
 
 /**
  * This library provides internationalization and localization. This includes
  * message formatting and replacement, date and number formatting and parsing,
  * and utilities for working with Bidirectional text.
  *
  * For things that require locale or other data, there are multiple different
@@ skipping 175 matching lines @@
     throw new ArgumentError("Invalid locale '$localeName'");
   }
 
   /** Return the short version of a locale name, e.g. 'en_US' => 'en' */
   static String _shortLocale(String aLocale) {
     if (aLocale.length < 2) return aLocale;
     return aLocale.substring(0, 2).toLowerCase();
   }
 
   /**
-   * Return a locale name turned into xx_YY where it might possibly be
-   * in the wrong case or with a hyphen instead of an underscore.
+   * Return the name [aLocale] turned into xx_YY where it might possibly be
+   * in the wrong case or with a hyphen instead of an underscore. If
+   * [aLocale] is null, for example, if you tried to get it from IE,
+   * return the current system locale.
    */
   static String canonicalizedLocale(String aLocale) {
     // Locales of length < 5 are presumably two-letter forms, or else malformed.
     // Locales of length > 6 are likely to be malformed. In either case we
     // return them unmodified and if correct they will be found.
     // We treat C as a special case, and assume it wants en_ISO for formatting.
     // TODO(alanknight): en_ISO is probably not quite right for the C/Posix
     // locale for formatting. Consider adding C to the formats database.
+    if (aLocale == null) return systemLocale;
     if (aLocale == "C") return "en_ISO";
     if ((aLocale.length < 5) || (aLocale.length > 6)) return aLocale;
     if (aLocale[2] != '-' && (aLocale[2] != '_')) return aLocale;
     var lastRegionLetter = aLocale.length == 5 ? "" : aLocale[5].toUpperCase();
     return '${aLocale[0]}${aLocale[1]}_${aLocale[3].toUpperCase()}'
            '${aLocale[4].toUpperCase()}$lastRegionLetter';
   }
 
   /**
    * Support method for message formatting. Select the correct plural form from
@@ skipping 45 matching lines @@
   /**
    * Accessor for the current locale. This should always == the default locale,
    * unless for some reason this gets called inside a message that resets the
    * locale.
    */
   static String getCurrentLocale() {
     if (_defaultLocale == null) _defaultLocale = systemLocale;
     return _defaultLocale;
   }
 }