Default to UTF-8 in the HTTP package.

pkg/http/lib/src/utils.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.
 
 library utils;
 
 import 'dart:async';
 import 'dart:crypto';
 import 'dart:io';
 import 'dart:typed_data';
@@ skipping 76 matching lines @@
 /// [FormatException] if no [Encoding] was found that corresponds to [charset].
 /// [charset] may not be null.
 Encoding requiredEncodingForCharset(String charset) {
   var encoding = Encoding.fromName(charset);
   if (encoding != null) return encoding;
   throw new FormatException('Unsupported encoding "$charset".');
 }
 
 /// Converts [bytes] into a [String] according to [encoding].
 String decodeString(List<int> bytes, Encoding encoding) {
   // TODO(nweiz): implement this once issue 6284 is fixed.

[Bob Nystrom, 2013/05/16 16:11:39]

How about throwing NotImplementedError if [encoding] is not UTF-8?

[nweiz, 2013/05/16 18:32:46]

I suspect most of the time when encodings get set to something other than the
default, they're coming from some external configuration rather than from the
user of http explicitly deciding they want ISO-8859-1 in particular. For
example, this gets called with an encoding that's derived from the response
headers. In cases like that, I think it's better to garble the non-ASCII text
(which may not even exist) than to just crash.

-  return new String.fromCharCodes(bytes);
+  return decodeUtf8(bytes);
 }
 
 /// Converts [string] into a byte array according to [encoding].
 List<int> encodeString(String string, Encoding encoding) {
   // TODO(nweiz): implement this once issue 6284 is fixed.

[Bob Nystrom, 2013/05/16 16:11:39]

Ditto.

-  return string.codeUnits;
+  return encodeUtf8(string);
 }
 
 /// A regular expression that matches strings that are composed entirely of
 /// ASCII-compatible characters.
 final RegExp _ASCII_ONLY = new RegExp(r"^[\x00-\x7F]+$");
 
 /// Returns whether [string] is composed entirely of ASCII-compatible
 /// characters.
 bool isPlainAscii(String string) => _ASCII_ONLY.hasMatch(string);
 
@@ skipping 117 matching lines @@
 /// The return values of all [Future]s are discarded. Any errors will cause the
 /// iteration to stop and will be piped through the return value.
 Future forEachFuture(Iterable input, Future fn(element)) {
   var iterator = input.iterator;
   Future nextElement(_) {
     if (!iterator.moveNext()) return new Future.value();
     return fn(iterator.current).then(nextElement);
   }
   return nextElement(null);
 }