[strong] Implement per-object restrictions behaviour of property freezing

src/v8natives.js

Index: src/v8natives.js
diff --git a/src/v8natives.js b/src/v8natives.js
index 180c05e1ebc81c4385dba9e6a347f0863ee93d47..08555a3d452ca883c3d1437f359f6894b40d586a 100644
--- a/src/v8natives.js
+++ b/src/v8natives.js
@@ -805,14 +805,24 @@ function DefineObjectProperty(obj, p, desc, should_throw) {
         }
         // Step 10a
         if (IsDataDescriptor(current) && IsDataDescriptor(desc)) {
-          if (!current.isWritable() && desc.isWritable()) {
-            if (should_throw) {
-              throw MakeTypeError(kRedefineDisallowed, p);
-            } else {
-              return false;
+          var currentIsWritable = current.isWritable();
+          if (currentIsWritable != desc.isWritable()) {
+            if (!currentIsWritable) {

[rossberg, 2015/05/22 13:10:28]

Nit:  if (!currentIsWritable || IS_STRONG(obj))  here

[conradw, 2015/05/22 14:07:08]

Done. Silly to miss this.

+              if (should_throw) {
+                throw MakeTypeError(kRedefineDisallowed, p);

[rossberg, 2015/05/22 13:10:28]

...and then  throw currentIsWritable ? MakeTypeError(...) : MakeTypeError(...) 
here

[conradw, 2015/05/22 14:07:08]

Done.

+              } else {
+                return false;
+              }
+            }
+            if (IS_STRONG(obj)) {

[rossberg, 2015/05/22 13:10:28]

...and eliminate this duplication

[conradw, 2015/05/22 14:07:08]

Done.

+              if (should_throw) {
+                throw MakeTypeError(kStrongRedefineDisallowed, p, obj);
+              } else {
+                return false;
+              }
             }
           }
-          if (!current.isWritable() && desc.hasValue() &&
+          if (!currentIsWritable && desc.hasValue() &&
               !$sameValue(desc.getValue(), current.getValue())) {
             if (should_throw) {
               throw MakeTypeError(kRedefineDisallowed, p);