Reviewers: Michael Starzinger,

Description:
Function declarations shall not overwrite read-only global properties.

[email protected]
BUG=115452
TEST=


Please review this at https://chromiumcodereview.appspot.com/9696035/

SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge

Affected files:
  M src/runtime.cc
  A test/mjsunit/regress/regress-115452.js


Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 019851e466a363948a3338c171eeac531b0290c4..195dc8808ec1c853499f1cac52bdd3492181d910 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -1336,6 +1336,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DeclareGlobals) {
       attr |= READ_ONLY;
     }

+    LanguageMode language_mode = DeclareGlobalsLanguageMode::decode(flags);
+
     // Safari does not allow the invocation of callback setters for
     // function declarations. To mimic this behavior, we do not allow
     // the invocation of setters for function values. This makes a
@@ -1343,9 +1345,18 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DeclareGlobals) {
     // handlers such as "function onload() {}". Firefox does call the
     // 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 (is_function_declaration) {
       if (lookup.IsProperty() && (lookup.type() != INTERCEPTOR)) {
+        // Do not overwrite READ_ONLY properties.
+        if (lookup.GetAttributes() & READ_ONLY) {
+          if (language_mode != CLASSIC_MODE) {
+            Handle<Object> args[] = { name };
+            return isolate->Throw(*isolate->factory()->NewTypeError(
+ "strict_cannot_assign", HandleVector(args, ARRAY_SIZE(args))));
+          }
+          continue;
+        }
+        // Do not change DONT_DELETE to false from true.
         attr |= lookup.GetAttributes() & DONT_DELETE;
       }
PropertyAttributes attributes = static_cast<PropertyAttributes>(attr); @@ -1355,14 +1366,12 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DeclareGlobals) {
           JSObject::SetLocalPropertyIgnoreAttributes(global, name, value,
                                                      attributes));
     } else {
- LanguageMode language_mode = DeclareGlobalsLanguageMode::decode(flags);
-      StrictModeFlag strict_mode_flag = (language_mode == CLASSIC_MODE)
-          ? kNonStrictMode : kStrictMode;
       RETURN_IF_EMPTY_HANDLE(
           isolate,
           JSReceiver::SetProperty(global, name, value,
                                   static_cast<PropertyAttributes>(attr),
-                                  strict_mode_flag));
+                                  language_mode == CLASSIC_MODE
+                                      ? kNonStrictMode : kStrictMode));
     }
   }

Index: test/mjsunit/regress/regress-115452.js
diff --git a/test/mjsunit/regress/regress-115452.js b/test/mjsunit/regress/regress-115452.js
new file mode 100644
index 0000000000000000000000000000000000000000..931f9934c3a98ef19b1e83e71419d9338797feaf
--- /dev/null
+++ b/test/mjsunit/regress/regress-115452.js
@@ -0,0 +1,48 @@
+// Copyright 2012 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 a function declaration cannot overwrite a read-only property.
+
+print(0)
+function foobl() {}
+assertTrue(typeof this.foobl == "function");
+assertTrue(Object.getOwnPropertyDescriptor(this, "foobl").writable);
+
+print(1)
+Object.defineProperty(this, "foobl", {value: 1, writable: false});
+assertEquals(1, this.foobl);
+assertFalse(Object.getOwnPropertyDescriptor(this, "foobl").writable);
+
+print(2)
+eval("function foobl() {}");
+assertEquals(1, this.foobl);
+assertFalse(Object.getOwnPropertyDescriptor(this, "foobl").writable);
+
+print(3)
+eval("function foobl() {}");
+assertEquals(1, this.foobl);
+assertFalse(Object.getOwnPropertyDescriptor(this, "foobl").writable);


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