Bug 836301 - Add Special handling to allow us to call enter() for defineProperty on Xrays. r=mrbkap

js/xpconnect/wrappers/FilteringWrapper.cpp

@@ -129,6 +129,22 @@ bool
 FilteringWrapper<Base, Policy>::enter(JSContext *cx, JSObject *wrapper, jsid id,
                                       Wrapper::Action act, bool *bp)
 {
+    // This is a super ugly hacky to get around Xray Resolve wonkiness.
+    //
+    // Basically, XPCWN Xrays sometimes call into the Resolve hook of the
+    // scriptable helper, and pass the wrapper itself as the object upon which
+    // the resolve is happening. Then, special handling happens in
+    // XrayWrapper::defineProperty to detect the resolve and redefine the
+    // property on the holder. Really, we should just pass the holder itself to
+    // NewResolve, but there's too much code in nsDOMClassInfo that assumes this
+    // isn't the case (in particular, code expects to be able to look up
+    // properties on the object, which doesn't work for the holder). Given that
+    // these hooks are going away eventually with the new DOM bindings, let's
+    // just hack around this for now.
+    if (XrayUtils::IsXrayResolving(cx, wrapper, id)) {
+        *bp = true;
+        return true;
+    }
     if (!Policy::check(cx, wrapper, id, act)) {
         if (JS_IsExceptionPending(cx)) {
             *bp = false;

js/xpconnect/wrappers/XrayWrapper.cpp

@@ -1317,6 +1317,19 @@ GetNativePropertiesObject(JSContext *cx, JSObject *wrapper)
     return holder;
 }
 
+bool
+IsXrayResolving(JSContext *cx, JSObject *wrapper, jsid id)
+{
+    if (!WrapperFactory::IsXrayWrapper(wrapper) ||
+        GetXrayType(wrapper) != XrayForWrappedNative)
+    {
+        return false;
+    }
+    JSObject *holder =
+      XPCWrappedNativeXrayTraits::singleton.ensureHolder(cx, wrapper);
+    return XPCWrappedNativeXrayTraits::isResolving(cx, holder, id);
+}
+
 }
 
 static JSBool

js/xpconnect/wrappers/XrayWrapper.h

@@ -38,6 +38,9 @@ IsTransparent(JSContext *cx, JSObject *wrapper, jsid id);
 JSObject *
 GetNativePropertiesObject(JSContext *cx, JSObject *wrapper);
 
+bool
+IsXrayResolving(JSContext *cx, JSObject *wrapper, jsid id);
+
 }
 
 class XrayTraits;