Fix updating of property attributes for elements.

This fixes updating of property attributes for data elements when
attributes are already present on a dictionary element but get removed
by a subsequent redefinition of that element.

R=rossberg@chromium.org
BUG=v8:1772
TEST=test262/15.2.3.6-4-82-18

Review URL: http://codereview.chromium.org/8337017

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9691 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/runtime.cc

@@ -4232,11 +4232,11 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DefineOrRedefineDataProperty) {
   uint32_t index;
   bool is_element = name->AsArrayIndex(&index);
 
-  // Special case for elements if any of the flags are true.
+  // Special case for elements if any of the flags might be involved.
   // If elements are in fast case we always implicitly assume that:
   // DONT_DELETE: false, DONT_ENUM: false, READ_ONLY: false.
-  if (((unchecked & (DONT_DELETE | DONT_ENUM | READ_ONLY)) != 0) &&
-      is_element) {
+  if (is_element && (attr != NONE ||
+      js_object->HasLocalElement(index) == JSObject::DICTIONARY_ELEMENT)) {
     // Normalize the elements to enable attributes on the property.
     if (js_object->IsJSGlobalProxy()) {
       // We do not need to do access checks here since these has already

test/test262/test262.status

@@ -322,12 +322,6 @@ S15.4.4.3_A2_T1: FAIL_OK
 
 ######################### UNANALYZED FAILURES ##########################
 
-# Bug? Object.defineProperty - Update [[Enumerable]] attribute of 'name'
-#      property to true successfully when [[Enumerable]] attribute of 'name'
-#      is false and [[Configurable]] attribute of 'name' is true,  the 'desc'
-#      is a generic descriptor which only contains [[Enumerable]] attribute
-#      as true, 'name' property is an index data property (8.12.9 step 8)
-15.2.3.6-4-82-18: FAIL
 # Bug? Object.defineProperty - 'O' is an Arguments object of a function that has
 #      formal parameters, 'name' is own property of 'O' which is also defined in
 #      [[ParameterMap]] of 'O', and 'desc' is data descriptor, test updating