Do not allow non-configurable global properties to be made configurable (fixes issue 1213).

We do not currently check that a global property is actually
configurable before overwriting it with a new property.


Review URL: http://codereview.chromium.org/6597045

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6978 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/runtime.cc

@@ -1104,6 +1104,11 @@ static MaybeObject* Runtime_DeclareGlobals(Arguments args) {
     // onload setter in those case and Safari does not. We follow
     // Safari for compatibility.
     if (value->IsJSFunction()) {
+      // Do not change DONT_DELETE to false from true.
+      if (lookup.IsProperty() && (lookup.type() != INTERCEPTOR)) {
+        attributes = static_cast<PropertyAttributes>(
+            attributes | (lookup.GetAttributes() & DONT_DELETE));
+      }
       RETURN_IF_EMPTY_HANDLE(SetLocalPropertyIgnoreAttributes(global,
                                                               name,
                                                               value,

test/mjsunit/regress/regress-1213.js

+// Copyright 2011 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Test that we do not allow overwriting a global property with a
+// redeclaration that makes the property configurable (and hence
+// deletable).
+
+var x = 0;
+
+function TestGlobal() {
+  for (var i = 0; i < 2; i++) {
+    x = x + 1;
+  }
+  this.eval('function x() {};');
+  delete this['x'];
+}
+
+TestGlobal();
+TestGlobal();