Bug 843840 part 1. Add a way to ask DOM proxies with a named getter whether a property is enumerable or not and use that information in getOwnPropertyDescriptor. r=peterv

content/base/src/nsDOMAttributeMap.cpp

@@ -217,6 +217,12 @@ nsDOMAttributeMap::NamedGetter(const nsAString& aAttrName, bool& aFound)
   return GetAttribute(ni, false);
 }
 
+bool
+nsDOMAttributeMap::NameIsEnumerable(const nsAString& aName)
+{
+  return true;
+}
+
 Attr*
 nsDOMAttributeMap::GetNamedItem(const nsAString& aAttrName)
 {

content/base/src/nsDOMAttributeMap.h

@@ -146,6 +146,7 @@ public:
   // WebIDL
   Attr* GetNamedItem(const nsAString& aAttrName);
   Attr* NamedGetter(const nsAString& aAttrName, bool& aFound);
+  bool NameIsEnumerable(const nsAString& aName);
   already_AddRefed<Attr>
   SetNamedItem(Attr& aAttr, ErrorResult& aError)
   {

content/html/content/public/nsIHTMLCollection.h

@@ -69,6 +69,10 @@ public:
   {
     return GetFirstNamedElement(aName, aFound);
   }
+  bool NameIsEnumerable(const nsAString& aName)
+  {
+    return false;
+  }
   virtual mozilla::dom::Element*
   GetFirstNamedElement(const nsAString& aName, bool& aFound) = 0;
 

content/html/content/src/HTMLFormElement.cpp

@@ -1434,6 +1434,12 @@ HTMLFormElement::NamedGetter(const nsAString& aName, bool &aFound)
   return nullptr;
 }
 
+bool
+HTMLFormElement::NameIsEnumerable(const nsAString& aName)
+{
+  return true;
+}
+
 void
 HTMLFormElement::GetSupportedNames(nsTArray<nsString >& aRetval)
 {

content/html/content/src/HTMLFormElement.h

@@ -395,6 +395,8 @@ public:
   already_AddRefed<nsISupports>
   NamedGetter(const nsAString& aName, bool &aFound);
 
+  bool NameIsEnumerable(const nsAString& aName);
+
   void GetSupportedNames(nsTArray<nsString >& aRetval);
 
   static int32_t

content/html/content/src/HTMLPropertiesCollection.h

@@ -86,6 +86,10 @@ public:
     aFound = IsSupportedNamedProperty(aName);
     return aFound ? NamedItem(aName) : nullptr;
   }
+  bool NameIsEnumerable(const nsAString& aName)
+  {
+    return true;
+  }
   DOMStringList* Names()
   {
     EnsureFresh();

content/html/content/src/nsDOMStringMap.cpp

@@ -91,6 +91,12 @@ nsDOMStringMap::NamedGetter(const nsAString& aProp, bool& found,
   found = mElement->GetAttr(attr, aResult);
 }
 
+bool
+nsDOMStringMap::NameIsEnumerable(const nsAString& aName)
+{
+  return true;
+}
+
 void
 nsDOMStringMap::NamedSetter(const nsAString& aProp,
                             const nsAString& aValue,

content/html/content/src/nsDOMStringMap.h

@@ -42,6 +42,7 @@ public:
   void NamedSetter(const nsAString& aProp, const nsAString& aValue,
                    mozilla::ErrorResult& rv);
   void NamedDeleter(const nsAString& aProp, bool &found);
+  bool NameIsEnumerable(const nsAString& aName);
   void GetSupportedNames(nsTArray<nsString>& aNames);
 
   js::ExpandoAndGeneration mExpandoAndGeneration;

content/html/document/src/nsHTMLDocument.cpp

@@ -2264,6 +2264,12 @@ nsHTMLDocument::NamedGetter(JSContext* cx, const nsAString& aName, bool& aFound,
   return &val.toObject();
 }
 
+bool
+nsHTMLDocument::NameIsEnumerable(const nsAString& aName)
+{
+  return true;
+}
+
 static PLDHashOperator
 IdentifierMapEntryAddNames(nsIdentifierMapEntry* aEntry, void* aArg)
 {

content/html/document/src/nsHTMLDocument.h

@@ -174,6 +174,7 @@ public:
   void SetCookie(const nsAString& aCookie, mozilla::ErrorResult& rv);
   JSObject* NamedGetter(JSContext* cx, const nsAString& aName, bool& aFound,
                         mozilla::ErrorResult& rv);
+  bool NameIsEnumerable(const nsAString& aName);
   void GetSupportedNames(nsTArray<nsString>& aNames);
   nsGenericHTMLElement *GetBody();
   void SetBody(nsGenericHTMLElement* aBody, mozilla::ErrorResult& rv);

dom/base/nsMimeTypeArray.cpp

@@ -173,6 +173,12 @@ nsMimeTypeArray::NamedGetter(const nsAString& aName, bool &aFound)
   return mt;
 }
 
+bool
+nsMimeTypeArray::NameIsEnumerable(const nsAString& aName)
+{
+  return true;
+}
+
 uint32_t
 nsMimeTypeArray::Length()
 {

dom/base/nsMimeTypeArray.h

@@ -36,6 +36,7 @@ public:
   nsMimeType* NamedItem(const nsAString& name);
   nsMimeType* IndexedGetter(uint32_t index, bool &found);
   nsMimeType* NamedGetter(const nsAString& name, bool &found);
+  bool NameIsEnumerable(const nsAString& name);
   uint32_t Length();
   void GetSupportedNames(nsTArray< nsString >& retval);
 

dom/base/nsPluginArray.cpp

@@ -222,6 +222,12 @@ nsPluginArray::NamedGetter(const nsAString& aName, bool &aFound)
   return plugin;
 }
 
+bool
+nsPluginArray::NameIsEnumerable(const nsAString& aName)
+{
+  return true;
+}
+
 uint32_t
 nsPluginArray::Length()
 {
@@ -440,6 +446,12 @@ nsPluginElement::NamedGetter(const nsAString& aName, bool &aFound)
   return nullptr;
 }
 
+bool
+nsPluginElement::NameIsEnumerable(const nsAString& aName)
+{
+  return true;
+}
+
 uint32_t
 nsPluginElement::Length()
 {

dom/base/nsPluginArray.h

@@ -52,6 +52,7 @@ public:
   void Refresh(bool aReloadDocuments);
   nsPluginElement* IndexedGetter(uint32_t aIndex, bool &aFound);
   nsPluginElement* NamedGetter(const nsAString& aName, bool &aFound);
+  bool NameIsEnumerable(const nsAString& aName);
   uint32_t Length();
   void GetSupportedNames(nsTArray< nsString >& aRetval);
 
@@ -101,6 +102,7 @@ public:
   nsMimeType* NamedItem(const nsAString& name);
   nsMimeType* IndexedGetter(uint32_t index, bool &found);
   nsMimeType* NamedGetter(const nsAString& name, bool &found);
+  bool NameIsEnumerable(const nsAString& aName);
   uint32_t Length();
   void GetSupportedNames(nsTArray< nsString >& retval);
 

dom/bindings/Codegen.py

@@ -8847,8 +8847,17 @@ MOZ_ASSERT_IF(desc.object(), desc.object() == ${holder});"""
             setOrIndexedGet += getUnforgeable
 
         if self.descriptor.supportsNamedProperties():
-            readonly = toStringBool(self.descriptor.operations['NamedSetter'] is None)
-            fillDescriptor = "FillPropertyDescriptor(desc, proxy, %s);\nreturn true;" % readonly
+            operations = self.descriptor.operations
+            readonly = toStringBool(operations['NamedSetter'] is None)
+            enumerable = (
+                "self->NameIsEnumerable(Constify(%s))" %
+                # First [0] means first (and only) signature, [1] means
+                # "arguments" as opposed to return type, [0] means first (and
+                # only) argument.
+                operations['NamedGetter'].signatures()[0][1][0].identifier.name)
+            fillDescriptor = (
+                "FillPropertyDescriptor(desc, proxy, %s, %s);\n"
+                "return true;" % (readonly, enumerable))
             templateValues = {'jsvalRef': 'desc.value()', 'jsvalHandle': 'desc.value()',
                               'obj': 'proxy', 'successCode': fillDescriptor}
             condition = "!HasPropertyOnPrototype(cx, proxy, id)"
@@ -11121,7 +11130,7 @@ class CGBindingImplClass(CGClass):
                                     []),
                                    {"infallible": True}))
         # And if we support named properties we need to be able to
-        # enumerate the supported names.
+        # enumerate the supported names and test whether they're enumerable.
         if descriptor.supportsNamedProperties():
             self.methodDecls.append(
                 CGNativeMember(
@@ -11131,6 +11140,15 @@ class CGBindingImplClass(CGClass):
                                      BuiltinTypes[IDLBuiltinType.Types.domstring]),
                      []),
                     {"infallible": True}))
+            self.methodDecls.append(
+                CGNativeMember(
+                    descriptor, FakeMember(),
+                    "NameIsEnumerable",
+                    (BuiltinTypes[IDLBuiltinType.Types.boolean],
+                     [FakeArgument(BuiltinTypes[IDLBuiltinType.Types.domstring],
+                                   FakeMember(),
+                                   name="aName")]),
+                    { "infallible": True }))
 
         wrapArgs = [Argument('JSContext*', 'aCx')]
         self.methodDecls.insert(0,

dom/bindings/DOMJSProxyHandler.h

@@ -139,20 +139,23 @@ IsArrayIndex(int32_t index)
 }
 
 inline void
-FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc, JSObject* obj, bool readonly)
+FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc,
+                       JSObject* obj, bool readonly, bool enumerable = true)
 {
   desc.object().set(obj);
-  desc.setAttributes((readonly ? JSPROP_READONLY : 0) | JSPROP_ENUMERATE);
+  desc.setAttributes((readonly ? JSPROP_READONLY : 0) |
+                     (enumerable ? JSPROP_ENUMERATE : 0));
   desc.setGetter(nullptr);
   desc.setSetter(nullptr);
 }
 
 inline void
-FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc, JSObject* obj, JS::Value v,
-                       bool readonly)
+FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc,
+                       JSObject* obj, JS::Value v,
+                       bool readonly, bool enumerable = true)
 {
   desc.value().set(v);
-  FillPropertyDescriptor(desc, obj, readonly);
+  FillPropertyDescriptor(desc, obj, readonly, enumerable);
 }
 
 inline void

dom/bindings/test/TestBindingHeader.h

@@ -989,6 +989,7 @@ public:
   virtual nsISupports* GetParentObject();
 
   void NamedGetter(const nsAString&, bool&, nsAString&);
+  bool NameIsEnumerable(const nsAString&);
   void GetSupportedNames(nsTArray<nsString>&);
 };
 
@@ -1002,6 +1003,7 @@ public:
   virtual nsISupports* GetParentObject();
 
   void NamedGetter(const nsAString&, bool&, nsAString&);
+  bool NameIsEnumerable(const nsAString&);
   void GetSupportedNames(nsTArray<nsString>&);
   int32_t IndexedGetter(uint32_t, bool&);
   void IndexedSetter(uint32_t, int32_t);
@@ -1019,6 +1021,7 @@ public:
 
   uint32_t IndexedGetter(uint32_t, bool&);
   void NamedGetter(const nsAString&, bool&, nsAString&);
+  bool NameIsEnumerable(const nsAString&);
   void NamedItem(const nsAString&, nsAString&);
   uint32_t Length();
   void GetSupportedNames(nsTArray<nsString>&);
@@ -1050,6 +1053,7 @@ public:
 
   void NamedSetter(const nsAString&, TestIndexedSetterInterface&);
   TestIndexedSetterInterface* NamedGetter(const nsAString&, bool&);
+  bool NameIsEnumerable(const nsAString&);
   void GetSupportedNames(nsTArray<nsString>&);
 };
 
@@ -1067,6 +1071,7 @@ public:
   uint32_t Length();
   void NamedSetter(const nsAString&, TestIndexedSetterInterface&);
   TestIndexedSetterInterface* NamedGetter(const nsAString&, bool&);
+  bool NameIsEnumerable(const nsAString&);
   void SetNamedItem(const nsAString&, TestIndexedSetterInterface&);
   void GetSupportedNames(nsTArray<nsString>&);
 };
@@ -1077,6 +1082,7 @@ public:
   uint32_t IndexedGetter(uint32_t, bool&);
   uint32_t Item(uint32_t);
   void NamedGetter(const nsAString&, bool&, nsAString&);
+  bool NameIsEnumerable(const nsAString&);
   void NamedItem(const nsAString&, nsAString&);
   void IndexedSetter(uint32_t, int32_t&);
   void IndexedSetter(uint32_t, const nsAString&) MOZ_DELETE;
@@ -1145,6 +1151,7 @@ public:
 
   void NamedDeleter(const nsAString&, bool&);
   long NamedGetter(const nsAString&, bool&);
+  bool NameIsEnumerable(const nsAString&);
   void GetSupportedNames(nsTArray<nsString>&);
 };
 
@@ -1160,6 +1167,7 @@ public:
   bool NamedDeleter(const nsAString&, bool&);
   bool NamedDeleter(const nsAString&) MOZ_DELETE;
   long NamedGetter(const nsAString&, bool&);
+  bool NameIsEnumerable(const nsAString&);
   bool DelNamedItem(const nsAString&);
   bool DelNamedItem(const nsAString&, bool&) MOZ_DELETE;
   void GetSupportedNames(nsTArray<nsString>&);
@@ -1181,6 +1189,7 @@ public:
   void NamedDeleter(const nsAString&, bool&);
   void NamedDeleter(const nsAString&) MOZ_DELETE;
   long NamedGetter(const nsAString&, bool&);
+  bool NameIsEnumerable(const nsAString&);
   void DelNamedItem(const nsAString&);
   void DelNamedItem(const nsAString&, bool&) MOZ_DELETE;
   void GetSupportedNames(nsTArray<nsString>&);

dom/bindings/test/mochitest.ini

@@ -35,6 +35,7 @@ skip-if = (toolkit == 'gonk' && debug) #debug-only failure; bug 926547
 [test_lenientThis.html]
 [test_lookupGetter.html]
 [test_namedNoIndexed.html]
+[test_named_getter_enumerability.html]
 [test_Object.prototype_props.html]
 [test_queryInterface.html]
 [test_sequence_wrapping.html]

dom/bindings/test/test_named_getter_enumerability.html

@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Test for named getter enumerability</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var list = document.getElementsByTagName("div");
+  var desc = Object.getOwnPropertyDescriptor(list, "0");
+  assert_equals(typeof desc, "object", "Should have a '0' property");
+  assert_true(desc.enumerable, "'0' property should be enumerable");
+  desc = Object.getOwnPropertyDescriptor(list, "log");
+  assert_equals(typeof desc, "object", "Should have a 'log' property");
+  assert_false(desc.enumerable, "'log' property should not be enumerable");
+}, "Correct getOwnPropertyDescriptor behavior");
+</script>

dom/imptests/html/dom/nodes/test_Document-getElementsByTagName.html

@@ -64,10 +64,15 @@ test(function() {
 
   assert_array_equals(Object.getOwnPropertyNames(list).sort(), ["0", "x"]);
 
-  var desc = Object.getOwnPropertyDescriptor(list, 'x');
+  var desc = Object.getOwnPropertyDescriptor(list, '0');
   assert_equals(typeof desc, "object", "descriptor should be an object");
   assert_true(desc.enumerable, "desc.enumerable");
   assert_true(desc.configurable, "desc.configurable");
+
+  desc = Object.getOwnPropertyDescriptor(list, 'x');
+  assert_equals(typeof desc, "object", "descriptor should be an object");
+  assert_false(desc.enumerable, "desc.enumerable");
+  assert_true(desc.configurable, "desc.configurable");
 }, "hasOwnProperty, getOwnPropertyDescriptor, getOwnPropertyNames")
 
 test(function() {

layout/xul/tree/nsTreeColumns.cpp

@@ -559,6 +559,12 @@ nsTreeColumns::NamedGetter(const nsAString& aId, bool& aFound)
   return nullptr;
 }
 
+bool
+nsTreeColumns::NameIsEnumerable(const nsAString& aName)
+{
+  return true;
+}
+
 nsTreeColumn*
 nsTreeColumns::GetNamedColumn(const nsAString& aId)
 {

layout/xul/tree/nsTreeColumns.h

@@ -157,6 +157,7 @@ public:
   nsTreeColumn* IndexedGetter(uint32_t aIndex, bool& aFound);
   nsTreeColumn* GetColumnAt(uint32_t aIndex);
   nsTreeColumn* NamedGetter(const nsAString& aId, bool& aFound);
+  bool NameIsEnumerable(const nsAString& aName);
   nsTreeColumn* GetNamedColumn(const nsAString& aId);
   void GetSupportedNames(nsTArray<nsString>& aNames);