Support preventExtensions in Proxy handlers

Change-Id: I03aaacc260bdb46eb09c597598a45fbb25d6d7b6
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

6 files changed, 46 insertions, 3 deletions

diff --git a/src/qml/jsruntime/qv4object.cpp b/src/qml/jsruntime/qv4object.cpp
index 751010fa4e..02acc1a5e0 100644
--- a/src/qml/jsruntime/qv4object.cpp
+++ b/src/qml/jsruntime/qv4object.cpp
@@ -1025,6 +1025,14 @@ bool Object::isExtensible(const Managed *m)
     return m->d()->internalClass->extensible;
 }
 
+bool Object::preventExtensions(Managed *m)
+{
+    Q_ASSERT(m->isObject());
+    Object *o = static_cast<Object *>(m);
+    o->setInternalClass(o->internalClass()->nonExtensible());
+    return true;
+}
+
 bool Object::setArrayLength(uint newLen)
 {
     Q_ASSERT(isArrayObject());
diff --git a/src/qml/jsruntime/qv4object_p.h b/src/qml/jsruntime/qv4object_p.h
index a9851984e1..b55e8f25e2 100644
--- a/src/qml/jsruntime/qv4object_p.h
+++ b/src/qml/jsruntime/qv4object_p.h
@@ -178,6 +178,7 @@ struct ObjectVTable
     bool (*hasProperty)(const Managed *m, Identifier id);
     PropertyAttributes (*getOwnProperty)(Managed *m, Identifier id, Property *p);
     bool (*isExtensible)(const Managed *);
+    bool (*preventExtensions)(Managed *);
     qint64 (*getLength)(const Managed *m);
     void (*advanceIterator)(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
     ReturnedValue (*instanceOf)(const Object *typeObject, const Value &var);
@@ -198,6 +199,7 @@ const QV4::ObjectVTable classname::static_vtbl =    \
     hasProperty,                                \
     getOwnProperty,                             \
     isExtensible,                               \
+    preventExtensions,                          \
     getLength,                                  \
     advanceIterator,                            \
     instanceOf                                  \
@@ -304,6 +306,7 @@ struct Q_QML_EXPORT Object: Managed {
     void insertMember(StringOrSymbol *s, const Property *p, PropertyAttributes attributes);
 
     bool isExtensible() const { return vtable()->isExtensible(this); }
+    bool preventExtensions() { return vtable()->preventExtensions(this); }
 
     // Array handling
 
@@ -441,6 +444,7 @@ protected:
     static bool hasProperty(const Managed *m, Identifier id);
     static PropertyAttributes getOwnProperty(Managed *m, Identifier id, Property *p);
     static bool isExtensible(const Managed *m);
+    static bool preventExtensions(Managed *);
     static void advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
     static qint64 getLength(const Managed *m);
     static ReturnedValue instanceOf(const Object *typeObject, const Value &var);
diff --git a/src/qml/jsruntime/qv4objectproto.cpp b/src/qml/jsruntime/qv4objectproto.cpp
index 72b2816dd9..84238477fd 100644
--- a/src/qml/jsruntime/qv4objectproto.cpp
+++ b/src/qml/jsruntime/qv4objectproto.cpp
@@ -401,7 +401,7 @@ ReturnedValue ObjectPrototype::method_preventExtensions(const FunctionObject *b,
     if (!o)
         return argv[0].asReturnedValue();
 
-    o->setInternalClass(o->internalClass()->nonExtensible());
+    o->preventExtensions();
     return o.asReturnedValue();
 }
 
diff --git a/src/qml/jsruntime/qv4proxy.cpp b/src/qml/jsruntime/qv4proxy.cpp
index 637a3c16df..e499dfbcf1 100644
--- a/src/qml/jsruntime/qv4proxy.cpp
+++ b/src/qml/jsruntime/qv4proxy.cpp
@@ -330,6 +330,37 @@ bool ProxyObject::isExtensible(const Managed *m)
     return result;
 }
 
+bool ProxyObject::preventExtensions(Managed *m)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler)
+        return scope.engine->throwTypeError();
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString hasProp(scope, scope.engine->newString(QStringLiteral("preventExtensions")));
+    ScopedValue trap(scope, handler->get(hasProp));
+    if (scope.hasException())
+        return Encode::undefined();
+    if (trap->isUndefined())
+        return target->preventExtensions();
+    if (!trap->isFunctionObject())
+        return scope.engine->throwTypeError();
+
+    JSCallData cdata(scope, 1, nullptr, handler);
+    cdata.args[0] = target;
+
+    ScopedValue trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    bool result = trapResult->toBoolean();
+    if (result && target->isExtensible()) {
+        scope.engine->throwTypeError();
+        return false;
+    }
+    return result;
+}
+
 //ReturnedValue ProxyObject::callAsConstructor(const FunctionObject *f, const Value *argv, int argc)
 //{
 
diff --git a/src/qml/jsruntime/qv4proxy_p.h b/src/qml/jsruntime/qv4proxy_p.h
index 36cf00aa47..a8b5b63a6c 100644
--- a/src/qml/jsruntime/qv4proxy_p.h
+++ b/src/qml/jsruntime/qv4proxy_p.h
@@ -94,6 +94,7 @@ struct ProxyObject: Object {
     static bool hasProperty(const Managed *m, Identifier id);
     static PropertyAttributes getOwnProperty(Managed *m, Identifier id, Property *p);
     static bool isExtensible(const Managed *m);
+    static bool preventExtensions(Managed *);
 
     // those might require a second proxy object that derives from FunctionObject...
 //    static ReturnedValue callAsConstructor(const FunctionObject *f, const Value *argv, int argc);
diff --git a/src/qml/jsruntime/qv4reflect.cpp b/src/qml/jsruntime/qv4reflect.cpp
index 69baecd337..219e28b6e7 100644
--- a/src/qml/jsruntime/qv4reflect.cpp
+++ b/src/qml/jsruntime/qv4reflect.cpp
@@ -232,8 +232,7 @@ ReturnedValue Reflect::method_preventExtensions(const FunctionObject *f, const V
         return scope.engine->throwTypeError();
 
     ScopedObject o(scope, static_cast<const Object *>(argv));
-    o->setInternalClass(o->internalClass()->nonExtensible());
-    return Encode(true);
+    return Encode(o->preventExtensions());
 }
 
 ReturnedValue Reflect::method_set(const FunctionObject *f, const Value *, const Value *argv, int argc)