Add regression-test for badly chained future-impementations.

tests/lib/async/future_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.
 
 library future_test;
 
 import 'dart:async';
 import 'dart:isolate';
 
 testImmediate() {
@@ skipping 500 matching lines @@
 
   var port = new ReceivePort();
   future.catchError((AsyncError e) {
     Expect.identical(error, e);
     port.close();
   });
 
   completer.completeError(error);
 }
 
+testChainedFutureValue() {
+  final completer = new Completer();
+  final future = completer.future;
+  var port = new ReceivePort();
+
+  future.then((v) => new Future.immediate(v * 2))
+        .then((v) {
+          Expect.equals(42, v);
+          port.close();
+        });
+  completer.complete(21);
+}
+
+testChainedFutureValueDelay() {
+  final completer = new Completer();
+  final future = completer.future;
+  var port = new ReceivePort();
+
+  future.then((v) => new Future.delayed(10, () => v * 2))
+        .then((v) {
+          Expect.equals(42, v);
+          port.close();
+        });
+  completer.complete(21);
+}
+
+testChainedFutureError() {
+  final completer = new Completer();
+  final future = completer.future;
+  var port = new ReceivePort();
+
+  future.then((v) => new Future.immediateError("Fehler"))
+        .then((v) { Expect.fail("unreachable!"); }, onError: (e) {
+          Expect.equals("Fehler", e.error);
+          port.close();
+        });
+  completer.complete(21);
+}
+
 main() {
   testImmediate();
   testNeverComplete();
 
   testComplete();
   testCompleteWithSuccessHandlerBeforeComplete();
   testCompleteWithSuccessHandlerAfterComplete();
   testCompleteManySuccessHandlers();
   testCompleteWithAsyncError();
 
@@ skipping 16 matching lines @@
 
   testFutureWhenValueFutureValue();
   testFutureWhenErrorFutureValue();
   testFutureWhenValueFutureError();
   testFutureWhenErrorFutureError();
 
   testFutureThenThrowsAsync();
   testFutureCatchThrowsAsync();
   testFutureWhenThrowsAsync();
   testFutureCatchRethrowsAsync();
+
+  testChainedFutureValue();
+  testChainedFutureValueDelay();
+  testChainedFutureError();
 }