First cut at bug 992

src/v8natives.js

 // Copyright 2006-2008 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
@@ skipping 527 matching lines @@
 // ES5 8.12.9.
 function DefineOwnProperty(obj, p, desc, should_throw) {
   var current = GetOwnProperty(obj, p);
   var extensible = %IsExtensible(ToObject(obj));
 
   // Error handling according to spec.
   // Step 3
   if (IS_UNDEFINED(current) && !extensible)
     throw MakeTypeError("define_disallowed", ["defineProperty"]);
 
-  if (!IS_UNDEFINED(current) && !current.isConfigurable()) {
+  if (!IS_UNDEFINED(current)) {
     // Step 5 and 6
-    if ((!desc.hasEnumerable() ||
-         SameValue(desc.isEnumerable() && current.isEnumerable())) &&
+    if ((IsGenericDescriptor(desc) ||
+         IsDataDescriptor(desc) == IsDataDescriptor(current)) &&
+        (!desc.hasEnumerable() ||
+         SameValue(desc.isEnumerable(), current.isEnumerable())) &&
         (!desc.hasConfigurable() ||
          SameValue(desc.isConfigurable(), current.isConfigurable())) &&
         (!desc.hasWritable() ||
          SameValue(desc.isWritable(), current.isWritable())) &&
         (!desc.hasValue() ||
          SameValue(desc.getValue(), current.getValue())) &&
         (!desc.hasGetter() ||
          SameValue(desc.getGet(), current.getGet())) &&
         (!desc.hasSetter() ||
          SameValue(desc.getSet(), current.getSet()))) {
       return true;
     }
-
-    // Step 7
-    if (desc.isConfigurable() || desc.isEnumerable() != current.isEnumerable())
-      throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
-    // Step 9
-    if (IsDataDescriptor(current) != IsDataDescriptor(desc))
-      throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
-    // Step 10
-    if (IsDataDescriptor(current) && IsDataDescriptor(desc)) {
-      if (!current.isWritable() && desc.isWritable())
+    if (!current.isConfigurable()) {
+      // Step 7
+      if (desc.isConfigurable() ||
+          (desc.hasEnumerable() &&
+           desc.isEnumerable() != current.isEnumerable()))
         throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
-      if (!current.isWritable() && desc.hasValue() &&
-          !SameValue(desc.getValue(), current.getValue())) {
-        throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
+      // Step 8
+      if (!IsGenericDescriptor(desc)) {
+        // Step 9a
+        if (IsDataDescriptor(current) != IsDataDescriptor(desc))
+          throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
+        // Step 10a
+        if (IsDataDescriptor(current) && IsDataDescriptor(desc)) {
+          if (!current.isWritable() && desc.isWritable())
+            throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
+          if (!current.isWritable() && desc.hasValue() &&
+              !SameValue(desc.getValue(), current.getValue())) {
+            throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
+          }
+        }
+        // Step 11
+        if (IsAccessorDescriptor(desc) && IsAccessorDescriptor(current)) {
+          if (desc.hasSetter() && !SameValue(desc.getSet(), current.getSet())){
+            throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
+          }
+          if (desc.hasGetter() && !SameValue(desc.getGet(),current.getGet()))
+            throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
+        }
       }
     }
-    // Step 11
-    if (IsAccessorDescriptor(desc) && IsAccessorDescriptor(current)) {
-      if (desc.hasSetter() && !SameValue(desc.getSet(), current.getSet())){
-        throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
-      }
-      if (desc.hasGetter() && !SameValue(desc.getGet(),current.getGet()))
-        throw MakeTypeError("redefine_disallowed", ["defineProperty"]);
-    }
   }
 
   // Send flags - enumerable and configurable are common - writable is
   // only send to the data descriptor.
   // Take special care if enumerable and configurable is not defined on
   // desc (we need to preserve the existing values from current).
   var flag = NONE;
   if (desc.hasEnumerable()) {
     flag |= desc.isEnumerable() ? 0 : DONT_ENUM;
   } else if (!IS_UNDEFINED(current)) {
     flag |= current.isEnumerable() ? 0 : DONT_ENUM;
   } else {
     flag |= DONT_ENUM;
   }
 
   if (desc.hasConfigurable()) {
     flag |= desc.isConfigurable() ? 0 : DONT_DELETE;
   } else if (!IS_UNDEFINED(current)) {
     flag |= current.isConfigurable() ? 0 : DONT_DELETE;
   } else
     flag |= DONT_DELETE;
 
-  if (IsDataDescriptor(desc) || IsGenericDescriptor(desc)) {
+  if (IsDataDescriptor(desc) ||
+      (IsGenericDescriptor(desc) &&
+       (IS_UNDEFINED(current) || IsDataDescriptor(current)))) {
+    // There are 3 cases that lead here:
+    // Step 4a - defining a new data property.
+    // Steps 9b & 12 - replacing an existing accessor property with a data
+    //                 property.
+    // Step 12 - updating an existing data property with a data or generic
+    //           descriptor.
+
     if (desc.hasWritable()) {
       flag |= desc.isWritable() ? 0 : READ_ONLY;
     } else if (!IS_UNDEFINED(current)) {
       flag |= current.isWritable() ? 0 : READ_ONLY;
     } else {
       flag |= READ_ONLY;
     }
+
     var value = void 0;  // Default value is undefined.
     if (desc.hasValue()) {
       value = desc.getValue();
-    } else if (!IS_UNDEFINED(current)) {
+    } else if (!IS_UNDEFINED(current) && IsDataDescriptor(current)) {
       value = current.getValue();
     }
+
     %DefineOrRedefineDataProperty(obj, p, value, flag);
+  } else if (IsGenericDescriptor(desc)) {
+    // Step 12 - updating an existing accessor property with generic

[Rico, 2011/01/07 09:47:30]

with generic -> with a generic

+    //           descriptor. Changing flags only.
+    %DefineOrRedefineAccessorProperty(obj, p, GETTER, current.getGet(), flag);
   } else {
-    if (desc.hasGetter() &&
-        (IS_FUNCTION(desc.getGet()) || IS_UNDEFINED(desc.getGet()))) {
-       %DefineOrRedefineAccessorProperty(obj, p, GETTER, desc.getGet(), flag);
+    // There are 3 cases that lead here:
+    // Step 4b - defining a new accessor property.
+    // Steps 9c & 12 - replacing an existing data property with an accessor
+    //                 property.
+    // Step 12 - updating an existing accessor property with an accessor
+    //           descriptor.
+    if (desc.hasGetter()) {
+      %DefineOrRedefineAccessorProperty(obj, p, GETTER, desc.getGet(), flag);
     }
-    if (desc.hasSetter() &&
-        (IS_FUNCTION(desc.getSet()) || IS_UNDEFINED(desc.getSet()))) {
+    if (desc.hasSetter()) {
       %DefineOrRedefineAccessorProperty(obj, p, SETTER, desc.getSet(), flag);
     }
   }
   return true;
 }
 
 
 // ES5 section 15.2.3.2.
 function ObjectGetPrototypeOf(obj) {
   if (!IS_SPEC_OBJECT(obj))
@@ skipping 533 matching lines @@
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "bind", FunctionBind,
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();