Fix for conditional expressions

test/checker/checker_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.
 
 /// General type checking tests
 library dev_compiler.test.checker_test;
 
 import 'package:unittest/compact_vm_config.dart';
 import 'package:unittest/unittest.dart';
 
@@ skipping 1530 matching lines @@
           }
           void foo(Object o) {
             var a = const A(/*$error*/o);
           }
      ''';
     testChecker({'/main.dart': mk("severe:StaticTypeError")},
         allowConstCasts: false);
     testChecker({'/main.dart': mk("info:DownCast")}, allowConstCasts: true);
   });
 
+  test('casts in conditionals', () {
+    testChecker({
+      '/main.dart': '''
+          main() {
+            bool b = true;
+            num x = b ? 1 : 2.3;
+            int y = /*info:DownCast*/b ? 1 : 2.3;
+            String z = !b ? "hello" : null;
+            z = b ? null : "hello";
+          }
+      '''
+    });
+  });
+
   test('redirecting constructor', () {
     testChecker({
       '/main.dart': '''
           class A {
             A(A x) {}
             A.two() : this(/*severe:StaticTypeError*/3);
           }
        '''
     });
   });
@@ skipping 1143 matching lines @@
         '/main.dart': '''
             class A {}
             class T1 implements A {
                 /*severe:InferableOverride*/toString() {}
             }
          '''
       }, inferFromOverrides: false);
     });
   });
 }