Import wpt@357b83b809e3cbc7a1805e7c3ca108a7980d782f

third_party/WebKit/LayoutTests/imported/wpt/html/semantics/forms/the-form-element/form-indexed-element.html

Index: third_party/WebKit/LayoutTests/imported/wpt/html/semantics/forms/the-form-element/form-indexed-element.html
diff --git a/third_party/WebKit/LayoutTests/imported/wpt/html/semantics/forms/the-form-element/form-indexed-element.html b/third_party/WebKit/LayoutTests/imported/wpt/html/semantics/forms/the-form-element/form-indexed-element.html
index 44471aa8ca309675167584f8b63d6de6e16162b4..66f00e7615d59d1649b9793f3d475bc7ce39b810 100644
--- a/third_party/WebKit/LayoutTests/imported/wpt/html/semantics/forms/the-form-element/form-indexed-element.html
+++ b/third_party/WebKit/LayoutTests/imported/wpt/html/semantics/forms/the-form-element/form-indexed-element.html
@@ -18,5 +18,28 @@ test(function() {
   assert_equals(form[1], document.getElementById("r2"));
   assert_equals(form[2], undefined);
   assert_equals(form[-1], undefined);
-  }, "form.elements should be accessed correctly by index")
+}, "form.elements should be accessed correctly by index")
+
+test(function(){
+  var form = document.getElementById("form");
+  var old_item = form[0];
+  var old_desc = Object.getOwnPropertyDescriptor(form, 0);
+  assert_equals(old_desc.value, old_item);
+  assert_true(old_desc.enumerable);
+  assert_true(old_desc.configurable);
+  assert_false(old_desc.writable);
+
+  Object.prototype[0] = 5;
+  this.add_cleanup(function () { delete Object.prototype[0]; });
+  assert_equals(form[0], old_item);
+
+  delete form[0];
+  assert_equals(form[0], old_item);
+
+  assert_throws(new TypeError(), function() {
+    "use strict";
+    delete form[0];
+  });
+  assert_equals(form[0], old_item);
+}, 'Trying to delete an indexed property name should never work');
 </script>