Fix bug in readAsString when charset is LATIN-1 and content-length is set.

test/loader_http_test.dart

 // Copyright (c) 2015, 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.
 
 @TestOn("vm")
 
 import "dart:convert";
 import "dart:io";
 
 import "package:resource/resource.dart";
@@ skipping 12 matching lines @@
       if (request.uri.path.endsWith(".not")) {
         request.response
           ..statusCode = HttpStatus.NOT_FOUND
           ..close();
         return;
       }
       var encodings = request.headers[HttpHeaders.ACCEPT_CHARSET];
       var encoding = parseAcceptCharset(encodings);
       request.response.headers.contentType =
           new ContentType("text", "plain", charset: encoding.name);
+      if (request.uri.query.contains("length")) {
+        request.response.headers.contentLength = content.length;
+      }
       request.response..write(content)
                       ..close();
     }).catchError(print);
   });
 
   test("Default encoding", () async {
     var loader = ResourceLoader.defaultLoader;
     String string = await loader.readAsString(uri);
     expect(string, content);
   });
 
   test("Latin-1 encoding", () async {
     var loader = ResourceLoader.defaultLoader;
     String string = await loader.readAsString(uri, encoding: LATIN1);
     expect(string, content);
   });
 
+  test("Latin-1 encoding w/ length", () async {
+    // Regression test for issue #21.
+    var loader = ResourceLoader.defaultLoader;
+    var newUri = uri.replace(query: "length");  // Request length set.
+    String string = await loader.readAsString(newUri, encoding: LATIN1);
+    expect(string, content);
+  });
+
   test("UTF-8 encoding", () async {
     var loader = ResourceLoader.defaultLoader;
     String string = await loader.readAsString(uri, encoding: UTF8);
     expect(string, content);
   });
 
   test("bytes", () async {
     var loader = ResourceLoader.defaultLoader;
     List<int> bytes = await loader.readAsBytes(uri);  // Sender uses Latin-1.
     expect(bytes, content.codeUnits);
@@ skipping 47 matching lines @@
         }
         if (w > weight) {
           weight = w;
           encoding = e;
         }
       }
     }
   }
   return encoding;
 }