Modify Object.{freeze,seal,isFrozen,isSealed} to avoid the problematic "caller" method on Functions.

src/v8natives.js

Index: src/v8natives.js
diff --git a/src/v8natives.js b/src/v8natives.js
index 20fc74dc440dcf28dd64ece1de30133611aadf0b..7c8381812bb86158ad554bd6e774f42cab974eb5 100644
--- a/src/v8natives.js
+++ b/src/v8natives.js
@@ -1154,6 +1154,17 @@ function ProxyFix(obj) {
   ObjectDefineProperties(obj, props);
 }
 
+function GetOwnPropertyNamesForSealOrFreeze(obj) {
+  var names = ObjectGetOwnPropertyNames(obj);
+  if (IS_SPEC_FUNCTION(obj)) {

[rossberg, 2012/11/16 12:28:55]

IS_FUNCTION probably is more adequate here, since it shouldn't be a proxy.

[arv (Not doing code reviews), 2012/11/16 14:38:06]

There are more poison pills than functionObj.caller

function.arguments
arguments.caller
arguments.callee

[rossberg, 2012/11/16 15:52:46]

Yes, but this issue affects only "caller", because it is due to its special
casing in 15.3.5.4.

+    // The "caller" property on Functions is always non-writable and
+    // non-configurable, so there's no need to check it or redefine it.
+    // Thus, we skip it to avoid the strict-mode check the getter enforces.
+    names = names.filter(function(name) { return name != "caller"; });
+  }
+  return names;
+}
+
 
 // ES5 section 15.2.3.8.
 function ObjectSeal(obj) {
@@ -1163,7 +1174,7 @@ function ObjectSeal(obj) {
   if (%IsJSProxy(obj)) {
     ProxyFix(obj);
   }
-  var names = ObjectGetOwnPropertyNames(obj);
+  var names = GetOwnPropertyNamesForSealOrFreeze(obj);
   for (var i = 0; i < names.length; i++) {
     var name = names[i];
     var desc = GetOwnProperty(obj, name);
@@ -1185,7 +1196,7 @@ function ObjectFreeze(obj) {
   if (%IsJSProxy(obj)) {
     ProxyFix(obj);
   }
-  var names = ObjectGetOwnPropertyNames(obj);
+  var names = GetOwnPropertyNamesForSealOrFreeze(obj);
   for (var i = 0; i < names.length; i++) {
     var name = names[i];
     var desc = GetOwnProperty(obj, name);
@@ -1221,7 +1232,7 @@ function ObjectIsSealed(obj) {
   if (%IsJSProxy(obj)) {
     return false;
   }
-  var names = ObjectGetOwnPropertyNames(obj);
+  var names = GetOwnPropertyNamesForSealOrFreeze(obj);
   for (var i = 0; i < names.length; i++) {
     var name = names[i];
     var desc = GetOwnProperty(obj, name);
@@ -1242,7 +1253,7 @@ function ObjectIsFrozen(obj) {
   if (%IsJSProxy(obj)) {
     return false;
   }
-  var names = ObjectGetOwnPropertyNames(obj);
+  var names = GetOwnPropertyNamesForSealOrFreeze(obj);
   for (var i = 0; i < names.length; i++) {
     var name = names[i];
     var desc = GetOwnProperty(obj, name);