Bug 965898 - Implement proper behavior for [[Enumerate]] And [[OwnPropertyKeys]]. r=gabor

js/xpconnect/tests/mochitest/test_bug862380.html

@@ -20,7 +20,6 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=862380
 
   function checkNotEnumerable(obj) {
     try {
-      is(Object.getOwnPropertyNames(obj).length, 0, "Object.getOwnPropertyNames gives empty array");
       is(Object.keys(obj).length, 0, "Object.keys gives empty array");
       for (var i in obj)
         ok(false, "Enumerated something: " + i);

js/xpconnect/wrappers/AccessCheck.cpp

@@ -154,15 +154,13 @@ AccessCheck::isCrossOriginAccessPermitted(JSContext *cx, JSObject *wrapperArg, j
     if (act == Wrapper::CALL)
         return false;
 
+    if (act == Wrapper::ENUMERATE)
+        return true;
+
     RootedId id(cx, idArg);
     RootedObject wrapper(cx, wrapperArg);
     RootedObject obj(cx, Wrapper::wrappedObject(wrapper));
 
-    // For XOWs, we generally want to deny enumerate-like operations, but fail
-    // silently (see CrossOriginAccessiblePropertiesOnly::deny).
-    if (act == Wrapper::ENUMERATE)
-        return false;
-
     const char *name;
     const js::Class *clasp = js::GetObjectClass(obj);
     MOZ_ASSERT(!XrayUtils::IsXPCWNHolderClass(Jsvalify(clasp)), "shouldn't have a holder here");

js/xpconnect/wrappers/FilteringWrapper.cpp

@@ -219,6 +219,24 @@ CrossOriginXrayWrapper::getPrototypeOf(JSContext *cx, JS::HandleObject wrapper,
     return true;
 }
 
+bool
+CrossOriginXrayWrapper::getOwnPropertyNames(JSContext *cx, JS::Handle<JSObject*> wrapper,
+                                            JS::AutoIdVector &props) const
+{
+    // All properties on cross-origin objects are supposed |own|, despite what
+    // the underlying native object may report. Override the inherited trap to
+    // avoid passing JSITER_OWNONLY as a flag.
+    return SecurityXrayDOM::enumerate(cx, wrapper, JSITER_HIDDEN, props);
+}
+
+bool
+CrossOriginXrayWrapper::enumerate(JSContext *cx, JS::Handle<JSObject*> wrapper,
+                                  JS::AutoIdVector &props) const
+{
+    // Cross-origin properties are non-enumerable.
+    return true;
+}
+
 #define XOW FilteringWrapper<CrossOriginXrayWrapper, CrossOriginAccessiblePropertiesOnly>
 #define NNXOW FilteringWrapper<CrossCompartmentSecurityWrapper, Opaque>
 #define NNXOWC FilteringWrapper<CrossCompartmentSecurityWrapper, OpaqueWithCall>

js/xpconnect/wrappers/FilteringWrapper.h

@@ -69,6 +69,11 @@ class CrossOriginXrayWrapper : public SecurityXrayDOM {
                                           JS::Handle<jsid> id,
                                           JS::MutableHandle<JSPropertyDescriptor> desc) const MOZ_OVERRIDE;
 
+    virtual bool getOwnPropertyNames(JSContext *cx, JS::Handle<JSObject*> wrapper,
+                                     JS::AutoIdVector &props) const MOZ_OVERRIDE;
+    virtual bool enumerate(JSContext *cx, JS::Handle<JSObject*> wrapper,
+                           JS::AutoIdVector &props) const MOZ_OVERRIDE;
+
     virtual bool getPrototypeOf(JSContext *cx, JS::HandleObject wrapper,
                                 JS::MutableHandleObject protop) const MOZ_OVERRIDE;
 };

js/xpconnect/wrappers/XrayWrapper.cpp

@@ -1912,16 +1912,18 @@ XPCWrappedNativeXrayTraits::enumerateNames(JSContext *cx, HandleObject wrapper,
             return false;
     }
 
-    // Go through the properties we got and enumerate all native ones.
+    // Go through the properties we found on the underlying object and see if
+    // they appear on the XrayWrapper. If it throws (which may happen if the
+    // wrapper is a SecurityWrapper), just clear the exception and move on.
+    MOZ_ASSERT(!JS_IsExceptionPending(cx));
     if (!props.reserve(wnProps.length()))
         return false;
     for (size_t n = 0; n < wnProps.length(); ++n) {
         RootedId id(cx, wnProps[n]);
         bool hasProp;
-        if (!JS_HasPropertyById(cx, wrapper, id, &hasProp))
-            return false;
-        if (hasProp)
+        if (JS_HasPropertyById(cx, wrapper, id, &hasProp) && hasProp)
             props.infallibleAppend(id);
+        JS_ClearPendingException(cx);
     }
     return true;
 }
@@ -2669,10 +2671,6 @@ XrayWrapper<Base, Traits>::enumerate(JSContext *cx, HandleObject wrapper, unsign
                                      AutoIdVector &props) const
 {
     assertEnteredPolicy(cx, wrapper, JSID_VOID, BaseProxyHandler::ENUMERATE);
-    if (!AccessCheck::wrapperSubsumes(wrapper)) {
-        JS_ReportError(cx, "Not allowed to enumerate cross origin objects");
-        return false;
-    }
 
     // Enumerate expando properties first. Note that the expando object lives
     // in the target compartment.

js/xpconnect/wrappers/XrayWrapper.h

@@ -138,6 +138,7 @@ class XrayWrapper : public Base {
                                                           protop);
     }
 
+  protected:
     bool enumerate(JSContext *cx, JS::Handle<JSObject*> wrapper, unsigned flags,
                    JS::AutoIdVector &props) const;
 };