Fixes the scope of case labels so that duplicate case labels are properly detected

compiler/javatests/com/google/dart/compiler/resolver/ResolverTest.java

 // 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.
 
 package com.google.dart.compiler.resolver;
 
-import static com.google.dart.compiler.common.ErrorExpectation.errEx;
-
 import com.google.common.base.Joiner;
 import com.google.dart.compiler.DartCompilationError;
 import com.google.dart.compiler.ErrorCode;
 import com.google.dart.compiler.ast.DartClass;
 import com.google.dart.compiler.common.ErrorExpectation;
 import com.google.dart.compiler.type.DynamicType;
 import com.google.dart.compiler.type.InterfaceType;
 import com.google.dart.compiler.type.Type;
 import com.google.dart.compiler.type.Types;
 
+import static com.google.dart.compiler.common.ErrorExpectation.errEx;
+
 import junit.framework.Assert;
 
 import java.util.List;
 
 /**
  * Basic tests of the resolver.
  */
 public class ResolverTest extends ResolverTestCase {
   private final DartClass object = makeClass("Object", null);
   private final DartClass array = makeClass("Array", makeType("Object"), "E");
@@ skipping 924 matching lines @@
         "class MyClass<E> {",
         "  foo() {",
         "    a: b: while (true) { break a; } // ok",
         "    a: b: while (true) { break b; } // ok",
         "    a: b: while (true) { break c; } // error, no such label",
         "  }",
         "}"),
         ErrorExpectation.errEx(ResolverErrorCode.CANNOT_RESOLVE_LABEL, 6, 32, 1));
   }
 
+  public void test_multipleLabelsSwitch() {
+    resolveAndTest(Joiner.on("\n").join(
+        "class Object {}",
+        "foo() {",
+        "  switch(1) {",
+        "  a: case (0): break;",
+        "  a: case (1): break;",
+        "  }",
+        "}"),
+        ErrorExpectation.errEx(ResolverErrorCode.DUPLICATE_LABEL_IN_SWITCH_STATEMENT, 5, 3, 2));
+  }
+
   public void test_new_noSuchType() throws Exception {
     resolveAndTest(Joiner.on("\n").join(
         "class Object {}",
         "class MyClass {",
         "  foo() {",
         "    new Unknown();",
         "  }",
         "}"),
         ResolverErrorCode.NO_SUCH_TYPE);
   }
@@ skipping 367 matching lines @@
             "// filler filler filler filler filler filler filler filler filler filler",
             "class Object {}",
             "class A {",
             "  var x;",
             "  A() : x = foo() {}",
             "  foo() {}",
             "}",
             ""),
         errEx(ResolverErrorCode.INSTANCE_METHOD_FROM_INITIALIZER, 5, 13, 5));
   }
-  
+
   /**
    * "this" is not accessible to initializers, so reference of instance method is error.
    * <p>
    * http://code.google.com/p/dart/issues/detail?id=2477
    */
   public void test_referenceInstanceMethod_fromInitializer() throws Exception {
     resolveAndTest(
         Joiner.on("\n").join(
             "// filler filler filler filler filler filler filler filler filler filler",
             "class Object {}",
@@ skipping 17 matching lines @@
         "class C {",
         "  C(arg){}",
         "  C.named1() : this(topLevel());", // ok
         "  C.named2() : this(method());", // error, not a static method
         "  C.named3() : this(new A().method());", // ok
         "  method() {}",
         "}"),
         errEx(ResolverErrorCode.INSTANCE_METHOD_FROM_REDIRECT, 10, 21, 8));
   }
 }