Fix issue with skipping global object during lookup through

the prototype chain. In case we're skipping a global object,
we have to be careful not to use ICs for the load, because
it's possible to introduce variables on the global object
without a map change.
Review URL: http://codereview.chromium.org/149316

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2385 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects.cc

@@ -1711,6 +1711,10 @@ void JSObject::LocalLookupRealNamedProperty(String* name,
       if (IsGlobalObject()) {
         PropertyDetails d = property_dictionary()->DetailsAt(entry);
         if (d.IsDeleted()) {
+          // We've skipped a global object during lookup, so we cannot
+          // use inline caching because the map of the global object
+          // doesn't change if the property should be re-added.
+          result->DisallowCaching();
           result->NotFound();
           return;
         }

test/mjsunit/global-deleted-property-ic.js

@@ -0,0 +1,45 @@
+// Copyright 2009 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.
+
+function LoadX(obj) { return obj.x; }
+
+// Load x from the prototype of this. Make sure to initialize the IC.
+this.__proto__ = { x: 42 };
+for (var i = 0; i < 3; i++) assertEquals(42, LoadX(this));
+
+// Introduce a global variable and make sure we load that from LoadX.
+this.x = 87;
+for (var i = 0; i < 3; i++) assertEquals(87, LoadX(this));
+
+// Delete the global variable and make sure we get back to loading from
+// the prototype.
+delete this.x;
+for (var i = 0; i < 3; i++) assertEquals(42, LoadX(this));
+
+// ... and go back again to loading directly from the object.
+this.x = 99;
+for (var i = 0; i < 3; i++) assertEquals(99, LoadX(this));