Bug fix for issue 4256

compiler/javatests/com/google/dart/compiler/parser/NegativeParserTest.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.parser;
 
 import com.google.common.base.Joiner;
 import com.google.dart.compiler.CompilerTestCase;
 import com.google.dart.compiler.ast.DartClass;
 import com.google.dart.compiler.ast.DartIdentifier;
 import com.google.dart.compiler.ast.DartMethodDefinition;
@@ skipping 163 matching lines @@
         "class A {void f(void cb(int a, [int b = 12345, int c])) {}}",
         errEx(ParserErrorCode.DEFAULT_VALUE_CAN_NOT_BE_SPECIFIED_IN_CLOSURE, 1, 41, 5));
   }
 
   public void test_namedParameterValue_inSetter() {
     parseExpectErrors(
         "class A { set f([int b]); }",
         errEx(ParserErrorCode.NAMED_PARAMETER_NOT_ALLOWED, 1, 18, 5));
   }
 
+  public void test_missingEndOfOptionalParameters() {
+    parseExpectErrors(
+        "class A {void m(var p1, [var p2 = const []) {} }",
+        errEx(ParserErrorCode.MISSING_NAMED_PARAMETER_END, 1, 43, 1));
+  }
+
   public void test_namedParameterValue_inOperator() {
     parseExpectErrors(
         "class A { operator []=(int a, [int b]); }",
         errEx(ParserErrorCode.NAMED_PARAMETER_NOT_ALLOWED, 1, 32, 5));
   }
 
   /**
    * If keyword "extends" is mistyped in type parameters declaration, we should report about this
    * and then recover correctly.
    * <p>
@@ skipping 825 matching lines @@
   public void test_qualifiedType_inForIn() {
     parseExpectErrors(Joiner.on("\n").join(
         "// filler filler filler filler filler filler filler filler filler filler",
         "foo() {",
         "  for (pref.A a in elements) {",
         "  }",
         "}",
         ""));
   }
 }