Better handling of IPv6 with HTTP proxy

sdk/lib/io/http_impl.dart

 // Copyright (c) 2013, 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.
 
 part of dart.io;
 
 const int _HEADERS_BUFFER_SIZE = 8 * 1024;
 
 class _HttpIncoming extends Stream<List<int>> {
   final int _transferLength;
@@ skipping 1805 matching lines @@
       _proxyCredentials.removeAt(index);
     }
   }
 
   static String _findProxyFromEnvironment(Uri url,
                                           Map<String, String> environment) {
     checkNoProxy(String option) {
       if (option == null) return null;
       Iterator<String> names = option.split(",").map((s) => s.trim()).iterator;
       while (names.moveNext()) {
-        if (url.host.endsWith(names.current)) {
+        var name = names.current;
+        if ((name.startsWith("[") &&
+             name.endsWith("]") &&
+             "[${url.host}]" == name) ||
+            (name.isNotEmpty &&
+             url.host.endsWith(name))) {
           return "DIRECT";
         }
       }
       return null;
     }
 
     checkProxy(String option) {
       if (option == null) return null;
+      option = option.trim();
+      if (option.isEmpty) return null;
       int pos = option.indexOf("://");
       if (pos >= 0) {
         option = option.substring(pos + 3);
       }
       pos = option.indexOf("/");
       if (pos >= 0) {
         option = option.substring(0, pos);
       }
-      if (option.indexOf(":") == -1) option = "$option:1080";
+      // Add default port if no port configured.
+      if (option.indexOf("[") == 0) {
+        var pos = option.lastIndexOf(":");
+        if (option.indexOf("]") > pos) option = "$option:1080";
+      } else {
+        if (option.indexOf(":") == -1) option = "$option:1080";
+      }
       return "PROXY $option";
     }
 
     // Default to using the process current environment.
     if (environment == null) environment = _platformEnvironmentCache;
 
     String proxyCfg;
 
     String noProxy = environment["no_proxy"];
     if (noProxy == null) noProxy = environment["NO_PROXY"];
@@ skipping 320 matching lines @@
             proxy = proxy.substring(at + 1).trim();
             int colon = userinfo.indexOf(":");
             if (colon == -1 || colon == 0 || colon == proxy.length - 1) {
               throw new HttpException(
                   "Invalid proxy configuration $configuration");
             }
             username = userinfo.substring(0, colon).trim();
             password = userinfo.substring(colon + 1).trim();
           }
           // Look for proxy host and port.
-          int colon = proxy.indexOf(":");
+          int colon = proxy.lastIndexOf(":");
           if (colon == -1 || colon == 0 || colon == proxy.length - 1) {
             throw new HttpException(
                 "Invalid proxy configuration $configuration");
           }
           String host = proxy.substring(0, colon).trim();
+          if (host.startsWith("[") && host.endsWith("]")) {
+            host = host.substring(1, host.length - 2);
+          }
           String portString = proxy.substring(colon + 1).trim();
           int port;
           try {
             port = int.parse(portString);
           } on FormatException catch (e) {
             throw new HttpException(
                 "Invalid proxy configuration $configuration, "
                 "invalid port '$portString'");
           }
           proxies.add(new _Proxy(host, port, username, password));
@@ skipping 354 matching lines @@
 
 String _getHttpVersion() {
   var version = Platform.version;
   // Only include major and minor version numbers.
   int index = version.indexOf('.', version.indexOf('.') + 1);
   version = version.substring(0, index);
   return 'Dart/$version (dart:io)';
 }