Add substitutions even when type arguments are fixed.

tests/language/fixed_type_variable2_test.dart

Index: tests/language/fixed_type_variable2_test.dart
diff --git a/tests/language/fixed_type_variable2_test.dart b/tests/language/fixed_type_variable2_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..157fae34320ab4098241cdc72353f83f1cfcc080
--- /dev/null
+++ b/tests/language/fixed_type_variable2_test.dart
@@ -0,0 +1,87 @@
+// 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.
+
+// Test that type variables are passed on from subtypes that fixed the type
+// variable in inheritance.
+
+import 'package:expect/expect.dart';
+
+class A<T> {
+  B<T> createB() => new B<T>();
+}
+
+class NumA extends A<num> {
+}
+
+class B<T> {
+  T value;
+
+  void test(var o, bool expect) {
+    Expect.equals(expect, o is T);
+  }
+}
+
+class StringB extends B<String> {
+}
+
+class C<T> extends A<T> {
+}
+
+class IntC extends C<int> {
+}
+
+void main() {
+  testA(); /// 01: ok
+  testNumA(); /// 02: ok
+  testB(); /// 03: ok
+  testStringB(); /// 04: ok
+  testC(); /// 05: ok
+  testIntC(); /// 06: ok
+}
+
+void testA() {
+  var instanceA = new A<String>();
+  var instanceB = instanceA.createB();
+  instanceB.test(0.5, false);
+  instanceB.test(0, false);
+  instanceB.test('', true);
+}
+
+void testNumA() {
+  var instanceA = new NumA();
+  var instanceB = instanceA.createB();
+  instanceB.test(0.5, true);
+  instanceB.test(0, true);
+  instanceB.test('', false);
+}
+
+void testB() {
+  var instanceB = new B<int>();
+  instanceB.test(0.5, false);
+  instanceB.test(0, true);
+  instanceB.test('', false);
+}
+
+void testStringB() {
+  var instanceB = new StringB();
+  instanceB.test(0.5, false);
+  instanceB.test(0, false);
+  instanceB.test('', true);
+}
+
+void testC() {
+  var instanceA = new C<String>();
+  var instanceB = instanceA.createB();
+  instanceB.test(0.5, false);
+  instanceB.test(0, false);
+  instanceB.test('', true);
+}
+
+void testIntC() {
+  var instanceA = new IntC();
+  var instanceB = instanceA.createB();
+  instanceB.test(0.5, false);
+  instanceB.test(0, true);
+  instanceB.test('', false);
+}