Serialize maps without hashes.

tests/isolate/message3_test.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.
 
 // Dart test program for testing serialization of messages.
 // VMOptions=--enable_type_checks --enable_asserts
 
 library MessageTest;
 import 'dart:async';
 import 'dart:collection';
@@ skipping 193 matching lines @@
     Expect.equals(8, entry2.w);
   }
   )                     /// int32x4: ok
   ;
 
   ping.send({"foo": 499, "bar": 32});
   checks.add((x) {
     Expect.isTrue(x is LinkedHashMap);
     Expect.listEquals(["foo", "bar"], x.keys.toList());
     Expect.listEquals([499, 32], x.values.toList());
+    Expect.equals(499, x["foo"]);
+    Expect.equals(32, x["bar"]);
     // Must be mutable.
     x["foo"] = 22;
     Expect.equals(22, x["foo"]);
     // Must be extendable.
     x["gee"] = 499;
     Expect.equals(499, x["gee"]);
   });
 
+  Map<String, int> mapWithRemovedKey = {"foo": 499, "bar": 32};
+  mapWithRemovedKey.remove("foo");
+  ping.send(mapWithRemovedKey);
+  checks.add((x) {
+    Expect.isTrue(x is LinkedHashMap);
+    Expect.listEquals(["bar"], x.keys.toList());
+    Expect.listEquals([32], x.values.toList());
+    Expect.equals(32, x["bar"]);
+  });
+
+  // Test map where a key does not define ==/hashCode.
+  Map<A, int> mapWithIdentityKey = new Map<A, int>();
+  mapWithIdentityKey[new A()] = 499;
+  ping.send(mapWithIdentityKey);
+  checks.add((x) {
+    Expect.isTrue(x is LinkedHashMap);
+    int value = x.values.first;
+    Expect.equals(499, value);
+    A key = x.keys.first;
+    Expect.equals(499, x[key]);
+  });
+
   ping.send({0: 499, 1: 32});
   checks.add((x) {
     Expect.isTrue(x is LinkedHashMap);
     Expect.listEquals([0, 1], x.keys.toList());
     Expect.listEquals([499, 32], x.values.toList());
     // Must be mutable.
     x[0] = 22;
     Expect.equals(22, x[0]);
     // Must be extendable.
     x["gee"] = 499;
@@ skipping 197 matching lines @@
     .spawn(echoMain, [initialReplyPort.sendPort, testPort.sendPort])
     .then((_) => initialReplyPort.first)
     .then((SendPort ping) {
       runTests(ping, checks);
       Expect.isTrue(checks.length > 0);
       completer.future
         .then((_) => ping.send("halt"))
         .then((_) => asyncEnd());
     });
 }