Bug 1088228 part 4. Add a version of JS_CloneFunctionObject that allows passing in a scope chain. r=shu

js/src/jsapi.cpp

@@ -3919,6 +3919,21 @@ JS_CloneFunctionObject(JSContext *cx, HandleObject funobj, HandleObject parentAr
     return CloneFunctionObject(cx, fun, parent, fun->getAllocKind());
 }
 
+namespace JS {
+
+JS_PUBLIC_API(JSObject *)
+CloneFunctionObject(JSContext *cx, HandleObject funobj, AutoObjectVector &scopeChain)
+{
+    RootedObject dynamicScope(cx);
+    RootedObject unusedStaticScope(cx);
+    if (!CreateScopeObjectsForScopeChain(cx, scopeChain, &dynamicScope, &unusedStaticScope))
+        return nullptr;
+
+    return JS_CloneFunctionObject(cx, funobj, dynamicScope);
+}
+
+} // namespace JS
+
 JS_PUBLIC_API(JSObject *)
 JS_GetFunctionObject(JSFunction *fun)
 {

js/src/jsapi.h

@@ -3534,6 +3534,18 @@ JS_DefineFunctionById(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<jsid>
 extern JS_PUBLIC_API(JSObject *)
 JS_CloneFunctionObject(JSContext *cx, JS::Handle<JSObject*> funobj, JS::Handle<JSObject*> parent);
 
+namespace JS {
+
+/*
+ * As above, but providing an explicit scope chain.  scopeChain must not include
+ * the global object on it; that's implicit.  It needs to contain the other
+ * objects that should end up on the clone's scope chain.
+ */
+extern JS_PUBLIC_API(JSObject *)
+CloneFunctionObject(JSContext *cx, HandleObject funobj, AutoObjectVector &scopeChain);
+
+} // namespace JS
+
 /*
  * Given a buffer, return false if the buffer might become a valid
  * javascript statement with the addition of more lines.  Otherwise return