Use ReturnedValue for Managed::get().

Change-Id: Ia8f35d227b69d32e1f6a041283abbbd083aa34ca
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

43 files changed, 320 insertions, 190 deletions

diff --git a/src/qml/jsapi/qjsvalue.cpp b/src/qml/jsapi/qjsvalue.cpp
index eb2390fa01..7b0b8bc2fd 100644
--- a/src/qml/jsapi/qjsvalue.cpp
+++ b/src/qml/jsapi/qjsvalue.cpp
@@ -791,11 +791,15 @@ bool QJSValue::strictlyEquals(const QJSValue& other) const
 */
 QJSValue QJSValue::property(const QString& name) const
 {
+    ExecutionEngine *engine = d->engine;
+    if (!engine)
+        return QJSValue();
+    QV4::Scope scope(engine);
+
     Object *o = d->value.asObject();
     if (!o)
         return QJSValue();
 
-    ExecutionEngine *engine = d->engine;
     String *s = engine->newString(name);
     uint idx = s->asArrayIndex();
     if (idx < UINT_MAX)
@@ -804,7 +808,7 @@ QJSValue QJSValue::property(const QString& name) const
     s->makeIdentifier();
     QV4::ExecutionContext *ctx = engine->current;
     try {
-        QV4::Value v = o->get(s);
+        QV4::ScopedValue v(scope, o->get(s));
         return new QJSValuePrivate(engine, v);
     } catch (QV4::Exception &e) {
         e.accept(ctx);
@@ -826,14 +830,18 @@ QJSValue QJSValue::property(const QString& name) const
 */
 QJSValue QJSValue::property(quint32 arrayIndex) const
 {
+    ExecutionEngine *engine = d->engine;
+    if (!engine)
+        return QJSValue();
+
+    QV4::Scope scope(engine);
     Object *o = d->value.asObject();
     if (!o)
         return QJSValue();
 
-    ExecutionEngine *engine = d->engine;
     QV4::ExecutionContext *ctx = engine->current;
     try {
-        QV4::Value v = arrayIndex == UINT_MAX ? o->get(engine->id_uintMax) : o->getIndexed(arrayIndex);
+        QV4::ScopedValue v(scope, arrayIndex == UINT_MAX ? o->get(engine->id_uintMax) : o->getIndexed(arrayIndex).asReturnedValue());
         return new QJSValuePrivate(engine, v);
     } catch (QV4::Exception &e) {
         e.accept(ctx);
diff --git a/src/qml/jsapi/qjsvalueiterator.cpp b/src/qml/jsapi/qjsvalueiterator.cpp
index 545250f27a..2b074c3cb2 100644
--- a/src/qml/jsapi/qjsvalueiterator.cpp
+++ b/src/qml/jsapi/qjsvalueiterator.cpp
@@ -174,9 +174,11 @@ QJSValue QJSValueIterator::value() const
 
     QV4::Object *o = d_ptr->iterator.object;
     QV4::ExecutionEngine *engine = o->internalClass->engine;
+    QV4::Scope scope(engine);
+
     QV4::ExecutionContext *ctx = engine->current;
     try {
-        QV4::Value v;
+        QV4::ScopedValue v(scope);
         if (d_ptr->currentName)
             v = o->get(d_ptr->currentName);
         else if (d_ptr->currentIndex != UINT_MAX)
diff --git a/src/qml/jsruntime/qv4arrayobject.cpp b/src/qml/jsruntime/qv4arrayobject.cpp
index 280062eb0d..8942df0c22 100644
--- a/src/qml/jsruntime/qv4arrayobject.cpp
+++ b/src/qml/jsruntime/qv4arrayobject.cpp
@@ -123,7 +123,9 @@ uint ArrayPrototype::getLength(ExecutionContext *ctx, Object *o)
 {
     if (o->isArrayObject())
         return o->arrayLength();
-    return o->get(ctx->engine->id_length).toUInt32();
+    Scope scope(ctx);
+    ScopedValue v(scope, o->get(ctx->engine->id_length));
+    return v->toUInt32();
 }
 
 Value ArrayPrototype::method_isArray(SimpleCallContext *ctx)
@@ -135,10 +137,11 @@ Value ArrayPrototype::method_isArray(SimpleCallContext *ctx)
 
 Value ArrayPrototype::method_toString(SimpleCallContext *ctx)
 {
+    QV4::Scope scope(ctx);
     QV4::Object *o = ctx->thisObject.toObject(ctx);
-    FunctionObject *f = o->get(ctx->engine->newString("join")).asFunctionObject();
+    ScopedValue v(scope, o->get(ctx->engine->newString("join")));
+    FunctionObject *f = v->asFunctionObject();
     if (f) {
-        Scope scope(ctx);
         ScopedCallData d(scope, 0);
         d->thisObject = ctx->thisObject;
         return Value::fromReturnedValue(f->call(d));
@@ -183,6 +186,7 @@ Value ArrayPrototype::method_concat(SimpleCallContext *ctx)
 
 Value ArrayPrototype::method_join(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
     Value arg = ctx->argument(0);
 
     QString r4;
@@ -191,22 +195,22 @@ Value ArrayPrototype::method_join(SimpleCallContext *ctx)
     else
         r4 = arg.toString(ctx)->toQString();
 
-    Value self = ctx->thisObject;
-    const Value length = self.property(ctx, ctx->engine->id_length);
-    const quint32 r2 = Value::toUInt32(length.isUndefined() ? 0 : length.toNumber());
+    Scoped<Object> self(scope, ctx->thisObject);
+    ScopedValue length(scope, self->get(ctx->engine->id_length));
+    const quint32 r2 = Value::toUInt32(length->isUndefined() ? 0 : length->toNumber());
 
     static QSet<Object *> visitedArrayElements;
 
-    if (! r2 || visitedArrayElements.contains(self.objectValue()))
+    if (! r2 || visitedArrayElements.contains(self.getPointer()))
         return Value::fromString(ctx, QString());
 
     // avoid infinite recursion
-    visitedArrayElements.insert(self.objectValue());
+    visitedArrayElements.insert(self.getPointer());
 
     QString R;
 
     // ### FIXME
-    if (ArrayObject *a = self.asArrayObject()) {
+    if (ArrayObject *a = self->asArrayObject()) {
         for (uint i = 0; i < a->arrayLength(); ++i) {
             if (i)
                 R += r4;
@@ -219,22 +223,23 @@ Value ArrayPrototype::method_join(SimpleCallContext *ctx)
         //
         // crazy!
         //
-        Value r6 = self.property(ctx, ctx->engine->newString(QStringLiteral("0")));
-        if (!(r6.isUndefined() || r6.isNull()))
-            R = r6.toString(ctx)->toQString();
+        ScopedValue r6(scope, self->get(ctx->engine->newString(QStringLiteral("0"))));
+        if (!r6->isNullOrUndefined())
+            R = r6->toString(ctx)->toQString();
 
+        ScopedValue r12(scope);
         for (quint32 k = 1; k < r2; ++k) {
             R += r4;
 
             String *name = Value::fromDouble(k).toString(ctx);
-            Value r12 = self.property(ctx, name);
+            r12 = self->get(name);
 
-            if (! (r12.isUndefined() || r12.isNull()))
-                R += r12.toString(ctx)->toQString();
+            if (!r12->isNullOrUndefined())
+                R += r12->toString(ctx)->toQString();
         }
     }
 
-    visitedArrayElements.remove(self.objectValue());
+    visitedArrayElements.remove(self.getPointer());
     return Value::fromString(ctx, R);
 }
 
@@ -351,7 +356,7 @@ Value ArrayPrototype::method_shift(SimpleCallContext *ctx)
     if (pidx < UINT_MAX && (!instance->arrayAttributes || !instance->arrayAttributes[0].isGeneric()))
             front = instance->arrayData + pidx;
 
-    Value result = front ? instance->getValue(front, instance->arrayAttributes ? instance->arrayAttributes[pidx] : Attr_Data) : Value::undefinedValue();
+    Value result = front ? Value::fromReturnedValue(instance->getValue(front, instance->arrayAttributes ? instance->arrayAttributes[pidx] : Attr_Data)) : Value::undefinedValue();
 
     if (!instance->protoHasArray() && instance->arrayDataLen <= len) {
         if (!instance->sparseArray) {
@@ -392,7 +397,7 @@ Value ArrayPrototype::method_slice(SimpleCallContext *ctx)
     Object *o = ctx->thisObject.toObject(ctx);
 
     ArrayObject *result = ctx->engine->newArrayObject();
-    uint len = o->get(ctx->engine->id_length).toUInt32();
+    uint len = ArrayPrototype::getLength(ctx, o);
     double s = ctx->argument(0).toInteger();
     uint start;
     if (s < 0)
diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index 0bcee14064..1a1efc0b4c 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -405,6 +405,8 @@ void ExecutionContext::setProperty(String *name, const Value& value)
 
 ReturnedValue ExecutionContext::getProperty(String *name)
 {
+    Scope scope(this);
+    ScopedValue v(scope);
     name->makeIdentifier();
 
     if (name->isEqualTo(engine->id_this))
@@ -417,7 +419,7 @@ ReturnedValue ExecutionContext::getProperty(String *name)
             Object *w = static_cast<WithContext *>(ctx)->withObject;
             hasWith = true;
             bool hasProperty = false;
-            Value v = w->get(name, &hasProperty);
+            v = w->get(name, &hasProperty);
             if (hasProperty) {
                 return v.asReturnedValue();
             }
@@ -444,7 +446,7 @@ ReturnedValue ExecutionContext::getProperty(String *name)
             }
             if (c->activation) {
                 bool hasProperty = false;
-                Value v = c->activation->get(name, &hasProperty);
+                v = c->activation->get(name, &hasProperty);
                 if (hasProperty)
                     return v.asReturnedValue();
             }
@@ -456,7 +458,7 @@ ReturnedValue ExecutionContext::getProperty(String *name)
         else if (ctx->type == Type_GlobalContext) {
             GlobalContext *g = static_cast<GlobalContext *>(ctx);
             bool hasProperty = false;
-            Value v = g->global->get(name, &hasProperty);
+            v = g->global->get(name, &hasProperty);
             if (hasProperty)
                 return v.asReturnedValue();
         }
@@ -467,6 +469,8 @@ ReturnedValue ExecutionContext::getProperty(String *name)
 
 ReturnedValue ExecutionContext::getPropertyNoThrow(String *name)
 {
+    Scope scope(this);
+    ScopedValue v(scope);
     name->makeIdentifier();
 
     if (name->isEqualTo(engine->id_this))
@@ -479,7 +483,7 @@ ReturnedValue ExecutionContext::getPropertyNoThrow(String *name)
             Object *w = static_cast<WithContext *>(ctx)->withObject;
             hasWith = true;
             bool hasProperty = false;
-            Value v = w->get(name, &hasProperty);
+            v = w->get(name, &hasProperty);
             if (hasProperty) {
                 return v.asReturnedValue();
             }
@@ -506,7 +510,7 @@ ReturnedValue ExecutionContext::getPropertyNoThrow(String *name)
             }
             if (c->activation) {
                 bool hasProperty = false;
-                Value v = c->activation->get(name, &hasProperty);
+                v = c->activation->get(name, &hasProperty);
                 if (hasProperty)
                     return v.asReturnedValue();
             }
@@ -518,7 +522,7 @@ ReturnedValue ExecutionContext::getPropertyNoThrow(String *name)
         else if (ctx->type == Type_GlobalContext) {
             GlobalContext *g = static_cast<GlobalContext *>(ctx);
             bool hasProperty = false;
-            Value v = g->global->get(name, &hasProperty);
+            v = g->global->get(name, &hasProperty);
             if (hasProperty)
                 return v.asReturnedValue();
         }
@@ -528,6 +532,8 @@ ReturnedValue ExecutionContext::getPropertyNoThrow(String *name)
 
 ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Object **base)
 {
+    Scope scope(this);
+    ScopedValue v(scope);
     *base = 0;
     name->makeIdentifier();
 
@@ -541,7 +547,7 @@ ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Object **base)
             Object *w = static_cast<WithContext *>(ctx)->withObject;
             hasWith = true;
             bool hasProperty = false;
-            Value v = w->get(name, &hasProperty);
+            v = w->get(name, &hasProperty);
             if (hasProperty) {
                 *base = w;
                 return v.asReturnedValue();
@@ -569,7 +575,7 @@ ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Object **base)
             }
             if (c->activation) {
                 bool hasProperty = false;
-                Value v = c->activation->get(name, &hasProperty);
+                v = c->activation->get(name, &hasProperty);
                 if (hasProperty) {
                     if (ctx->type == Type_QmlContext)
                         *base = c->activation;
@@ -584,7 +590,7 @@ ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Object **base)
         else if (ctx->type == Type_GlobalContext) {
             GlobalContext *g = static_cast<GlobalContext *>(ctx);
             bool hasProperty = false;
-            Value v = g->global->get(name, &hasProperty);
+            v = g->global->get(name, &hasProperty);
             if (hasProperty)
                 return v.asReturnedValue();
         }
diff --git a/src/qml/jsruntime/qv4dateobject.cpp b/src/qml/jsruntime/qv4dateobject.cpp
index c2a15b8725..de56fcd5f3 100644
--- a/src/qml/jsruntime/qv4dateobject.cpp
+++ b/src/qml/jsruntime/qv4dateobject.cpp
@@ -1298,7 +1298,8 @@ Value DatePrototype::method_toJSON(SimpleCallContext *ctx)
     if (tv->isNumber() && !std::isfinite(tv->toNumber()))
         return Value::nullValue();
 
-    FunctionObject *toIso = O->objectValue()->get(ctx->engine->newString(QStringLiteral("toISOString"))).asFunctionObject();
+    ScopedValue v(scope, O->objectValue()->get(ctx->engine->newString(QStringLiteral("toISOString"))));
+    FunctionObject *toIso = v->asFunctionObject();
 
     if (!toIso)
         ctx->throwTypeError();
diff --git a/src/qml/jsruntime/qv4debugging.cpp b/src/qml/jsruntime/qv4debugging.cpp
index 6879e432e8..8080ed6c62 100644
--- a/src/qml/jsruntime/qv4debugging.cpp
+++ b/src/qml/jsruntime/qv4debugging.cpp
@@ -275,7 +275,7 @@ static void realDumpValue(QV4::Value v, QV4::ExecutionContext *ctx, std::string
         cout << prefix << "\t\"" << qPrintable(name.stringValue()->toQString()) << "\"" << endl;
         PropertyAttributes attrs;
         Property *d = o->__getOwnProperty__(name.stringValue(), &attrs);
-        Value pval = o->getValue(d, attrs);
+        Value pval = Value::fromReturnedValue(o->getValue(d, attrs));
         cout << prefix << "\tvalue:" << endl;
         realDumpValue(pval, ctx, prefix + "\t");
     }
diff --git a/src/qml/jsruntime/qv4functionobject.cpp b/src/qml/jsruntime/qv4functionobject.cpp
index 475874ce01..03d09a7bc4 100644
--- a/src/qml/jsruntime/qv4functionobject.cpp
+++ b/src/qml/jsruntime/qv4functionobject.cpp
@@ -138,7 +138,9 @@ bool FunctionObject::hasInstance(Managed *that, const Value &value)
         return false;
 
     ExecutionContext *ctx = f->engine()->current;
-    Object *o = f->get(ctx->engine->id_prototype).asObject();
+    QV4::Scope scope(ctx);
+
+    Scoped<Object> o(scope, f->get(ctx->engine->id_prototype));
     if (!o)
         ctx->throwTypeError();
 
@@ -147,7 +149,7 @@ bool FunctionObject::hasInstance(Managed *that, const Value &value)
 
         if (! v)
             break;
-        else if (o == v)
+        else if (o.getPointer() == v)
             return true;
     }
 
@@ -158,11 +160,12 @@ ReturnedValue FunctionObject::construct(Managed *that, CallData *)
 {
     FunctionObject *f = static_cast<FunctionObject *>(that);
     ExecutionEngine *v4 = f->engine();
+    Scope scope(v4);
 
     InternalClass *ic = v4->objectClass;
-    Value proto = f->get(v4->id_prototype);
-    if (proto.isObject())
-        ic = v4->emptyClass->changePrototype(proto.objectValue());
+    Scoped<Object> proto(scope, f->get(v4->id_prototype));
+    if (!!proto)
+        ic = v4->emptyClass->changePrototype(proto.getPointer());
     Object *obj = v4->newObject(ic);
     return Value::fromObject(obj).asReturnedValue();
 }
@@ -647,7 +650,7 @@ BoundFunction::BoundFunction(ExecutionContext *scope, FunctionObject *target, Va
     , boundArgs(boundArgs)
 {
     vtbl = &static_vtbl;
-    int len = target->get(scope->engine->id_length).toUInt32();
+    int len = Value::fromReturnedValue(target->get(scope->engine->id_length)).toUInt32();
     len -= boundArgs.size();
     if (len < 0)
         len = 0;
diff --git a/src/qml/jsruntime/qv4functionobject_p.h b/src/qml/jsruntime/qv4functionobject_p.h
index bc5bc5c8df..8869083d08 100644
--- a/src/qml/jsruntime/qv4functionobject_p.h
+++ b/src/qml/jsruntime/qv4functionobject_p.h
@@ -126,6 +126,10 @@ struct Q_QML_EXPORT FunctionObject: Object {
         return vtbl->call(this, callData);
     }
 
+    static FunctionObject *cast(const Value &v) {
+        return v.asFunctionObject();
+    }
+
     static FunctionObject *creatScriptFunction(ExecutionContext *scope, Function *function);
 
 protected:
diff --git a/src/qml/jsruntime/qv4jsonobject.cpp b/src/qml/jsruntime/qv4jsonobject.cpp
index 56e8d1ffe7..ea8afcbaf9 100644
--- a/src/qml/jsruntime/qv4jsonobject.cpp
+++ b/src/qml/jsruntime/qv4jsonobject.cpp
@@ -702,8 +702,8 @@ QString Stringify::Str(const QString &key, Value value)
     QString result;
 
     if (Object *o = value.asObject()) {
-        FunctionObject *toJSON = o->get(ctx->engine->newString(QStringLiteral("toJSON"))).asFunctionObject();
-        if (toJSON) {
+        Scoped<FunctionObject> toJSON(scope, o->get(ctx->engine->newString(QStringLiteral("toJSON"))));
+        if (!!toJSON) {
             ScopedCallData callData(scope, 1);
             callData->thisObject = value;
             callData->args[0] = Value::fromString(ctx, key);
@@ -773,6 +773,8 @@ QString Stringify::JO(Object *o)
     if (stack.contains(o))
         ctx->throwTypeError();
 
+    Scope scope(o->engine());
+
     QString result;
     stack.push(o);
     QString stepback = indent;
@@ -795,7 +797,7 @@ QString Stringify::JO(Object *o)
     } else {
         for (int i = 0; i < propertyList.size(); ++i) {
             bool exists;
-            Value v = o->get(propertyList.at(i), &exists);
+            ScopedValue v(scope, o->get(propertyList.at(i), &exists));
             if (!exists)
                 continue;
             QString member = makeMember(propertyList.at(i)->toQString(), v);
diff --git a/src/qml/jsruntime/qv4lookup.cpp b/src/qml/jsruntime/qv4lookup.cpp
index 35aaa1918a..e2392d84f5 100644
--- a/src/qml/jsruntime/qv4lookup.cpp
+++ b/src/qml/jsruntime/qv4lookup.cpp
@@ -137,7 +137,7 @@ void Lookup::getterGeneric(QV4::Lookup *l, QV4::Value *result, const QV4::Value
                 l->getter = Lookup::primitiveGetterAccessor1;
             if (result)
                 *result = p->value;
-            Value res = proto->getValue(object, p, attrs);
+            Value res = Value::fromReturnedValue(proto->getValue(object, p, attrs));
             if (result)
                 *result = res;
             return;
@@ -383,7 +383,7 @@ void Lookup::globalGetterGeneric(Lookup *l, ExecutionContext *ctx, Value *result
                 l->globalGetter = globalGetterAccessor1;
             else if (l->level == 2)
                 l->globalGetter = globalGetterAccessor2;
-            Value res = o->getValue(p, attrs);
+            Value res = Value::fromReturnedValue(o->getValue(p, attrs));
             if (result)
                 *result = res;
             return;
diff --git a/src/qml/jsruntime/qv4managed.cpp b/src/qml/jsruntime/qv4managed.cpp
index 711c7cf259..a8f70778c4 100644
--- a/src/qml/jsruntime/qv4managed.cpp
+++ b/src/qml/jsruntime/qv4managed.cpp
@@ -201,7 +201,7 @@ bool Managed::isEqualTo(Managed *, Managed *)
     return false;
 }
 
-Value Managed::get(String *name, bool *hasProperty)
+ReturnedValue Managed::get(String *name, bool *hasProperty)
 {
     return vtbl->get(this, name, hasProperty);
 }
diff --git a/src/qml/jsruntime/qv4managed_p.h b/src/qml/jsruntime/qv4managed_p.h
index 44d809c605..e72cf10bf8 100644
--- a/src/qml/jsruntime/qv4managed_p.h
+++ b/src/qml/jsruntime/qv4managed_p.h
@@ -97,7 +97,7 @@ struct ManagedVTable
     void (*destroy)(Managed *);
     void (*collectDeletables)(Managed *, GCDeletable **deletable);
     bool (*hasInstance)(Managed *, const Value &value);
-    Value (*get)(Managed *, String *name, bool *hasProperty);
+    ReturnedValue (*get)(Managed *, String *name, bool *hasProperty);
     Value (*getIndexed)(Managed *, uint index, bool *hasProperty);
     void (*put)(Managed *, String *name, const Value &value);
     void (*putIndexed)(Managed *, uint index, const Value &value);
@@ -223,6 +223,14 @@ public:
         return vtbl == &T::static_vtbl ? static_cast<const T *>(this) : 0;
     }
 
+    template<typename T>
+    static T *cast(const Value &v) {
+        return v.as<T>();
+    }
+    static Managed *cast(const Value &v) {
+        return v.asManaged();
+    }
+
     ArrayObject *asArrayObject() { return type == Type_ArrayObject ? reinterpret_cast<ArrayObject *>(this) : 0; }
     FunctionObject *asFunctionObject() { return type == Type_FunctionObject ? reinterpret_cast<FunctionObject *>(this) : 0; }
     BooleanObject *asBooleanObject() { return type == Type_BooleanObject ? reinterpret_cast<BooleanObject *>(this) : 0; }
@@ -254,7 +262,7 @@ public:
     }
     ReturnedValue construct(CallData *d);
     ReturnedValue call(CallData *d);
-    Value get(String *name, bool *hasProperty = 0);
+    ReturnedValue get(String *name, bool *hasProperty = 0);
     Value getIndexed(uint index, bool *hasProperty = 0);
     void put(String *name, const Value &value)
     { vtbl->put(this, name, value); }
diff --git a/src/qml/jsruntime/qv4object.cpp b/src/qml/jsruntime/qv4object.cpp
index 8b68b4811a..056430d5ea 100644
--- a/src/qml/jsruntime/qv4object.cpp
+++ b/src/qml/jsruntime/qv4object.cpp
@@ -127,18 +127,18 @@ void Object::put(ExecutionContext *ctx, const QString &name, const Value &value)
     put(ctx->engine->newString(name), value);
 }
 
-Value Object::getValue(const Value &thisObject, const Property *p, PropertyAttributes attrs)
+ReturnedValue Object::getValue(const Value &thisObject, const Property *p, PropertyAttributes attrs)
 {
     if (!attrs.isAccessor())
-        return p->value;
+        return p->value.asReturnedValue();
     FunctionObject *getter = p->getter();
     if (!getter)
-        return Value::undefinedValue();
+        return Value::undefinedValue().asReturnedValue();
 
     Scope scope(getter->engine());
     ScopedCallData callData(scope, 0);
     callData->thisObject = thisObject;
-    return Value::fromReturnedValue(getter->call(callData));
+    return getter->call(callData);
 }
 
 void Object::putValue(Property *pd, PropertyAttributes attrs, const Value &value)
@@ -449,7 +449,7 @@ bool Object::__hasProperty__(uint index) const
     return false;
 }
 
-Value Object::get(Managed *m, String *name, bool *hasProperty)
+ReturnedValue Object::get(Managed *m, String *name, bool *hasProperty)
 {
     return static_cast<Object *>(m)->internalGet(name, hasProperty);
 }
@@ -535,7 +535,7 @@ void Object::getLookup(Managed *m, Lookup *l, Value *result)
                 l->getter = Lookup::getterAccessor2;
             if (result)
                 *result = p->value;
-            Value res = o->getValue(p, attrs);
+            Value res = Value::fromReturnedValue(o->getValue(p, attrs));
             if (result)
                 *result = res;
             return;
@@ -654,11 +654,11 @@ Property *Object::advanceIterator(Managed *m, ObjectIterator *it, String **name,
 }
 
 // Section 8.12.3
-Value Object::internalGet(String *name, bool *hasProperty)
+ReturnedValue Object::internalGet(String *name, bool *hasProperty)
 {
     uint idx = name->asArrayIndex();
     if (idx != UINT_MAX)
-        return getIndexed(idx, hasProperty);
+        return getIndexed(idx, hasProperty).asReturnedValue();
 
     name->makeIdentifier();
 
@@ -676,7 +676,7 @@ Value Object::internalGet(String *name, bool *hasProperty)
 
     if (hasProperty)
         *hasProperty = false;
-    return Value::undefinedValue();
+    return Value::undefinedValue().asReturnedValue();
 }
 
 Value Object::internalGetIndexed(uint index, bool *hasProperty)
@@ -707,7 +707,7 @@ Value Object::internalGetIndexed(uint index, bool *hasProperty)
     if (pd) {
         if (hasProperty)
             *hasProperty = true;
-        return getValue(pd, attrs);
+        return Value::fromReturnedValue(getValue(pd, attrs));
     }
 
     if (hasProperty)
@@ -1244,11 +1244,11 @@ void Object::arraySort(ExecutionContext *context, Object *thisObject, const Valu
                 while (--len > i)
                     if (!arrayAttributes[len].isGeneric())
                         break;
-                arrayData[i].value = getValue(arrayData + len, arrayAttributes[len]);
+                arrayData[i].value = Value::fromReturnedValue(getValue(arrayData + len, arrayAttributes[len]));
                 arrayAttributes[i] = Attr_Data;
                 arrayAttributes[len].clear();
             } else if (arrayAttributes[i].isAccessor()) {
-                arrayData[i].value = getValue(arrayData + i, arrayAttributes[i]);
+                arrayData[i].value = Value::fromReturnedValue(getValue(arrayData + i, arrayAttributes[i]));
                 arrayAttributes[i] = Attr_Data;
             }
         }
diff --git a/src/qml/jsruntime/qv4object_p.h b/src/qml/jsruntime/qv4object_p.h
index c656985aea..738bfbf524 100644
--- a/src/qml/jsruntime/qv4object_p.h
+++ b/src/qml/jsruntime/qv4object_p.h
@@ -149,8 +149,8 @@ struct Q_QML_EXPORT Object: Managed {
     //
     void put(ExecutionContext *ctx, const QString &name, const Value &value);
 
-    static Value getValue(const Value &thisObject, const Property *p, PropertyAttributes attrs);
-    Value getValue(const Property *p, PropertyAttributes attrs) const {
+    static ReturnedValue getValue(const Value &thisObject, const Property *p, PropertyAttributes attrs);
+    ReturnedValue getValue(const Property *p, PropertyAttributes attrs) const {
         return getValue(Value::fromObject(const_cast<Object *>(this)), p, attrs);
     }
 
@@ -179,6 +179,10 @@ struct Q_QML_EXPORT Object: Managed {
 
     ReturnedValue asReturnedValue() { return Value::fromObject(this).asReturnedValue(); }
 
+    static Object *cast(const Value &v) {
+        return v.asObject();
+    }
+
     // Array handling
 
     uint allocArrayValue() {
@@ -289,7 +293,7 @@ public:
     }
     void ensureMemberIndex(uint idx);
 
-    inline Value get(String *name, bool *hasProperty = 0)
+    inline ReturnedValue get(String *name, bool *hasProperty = 0)
     { return vtbl->get(this, name, hasProperty); }
     inline Value getIndexed(uint idx, bool *hasProperty = 0)
     { return vtbl->getIndexed(this, idx, hasProperty); }
@@ -312,7 +316,7 @@ protected:
     static const ManagedVTable static_vtbl;
     static void destroy(Managed *that);
     static void markObjects(Managed *that);
-    static Value get(Managed *m, String *name, bool *hasProperty);
+    static ReturnedValue get(Managed *m, String *name, bool *hasProperty);
     static Value getIndexed(Managed *m, uint index, bool *hasProperty);
     static void put(Managed *m, String *name, const Value &value);
     static void putIndexed(Managed *m, uint index, const Value &value);
@@ -326,7 +330,7 @@ protected:
 
 
 private:
-    Value internalGet(String *name, bool *hasProperty);
+    ReturnedValue internalGet(String *name, bool *hasProperty);
     Value internalGetIndexed(uint index, bool *hasProperty);
     void internalPut(String *name, const Value &value);
     void internalPutIndexed(uint index, const Value &value);
diff --git a/src/qml/jsruntime/qv4objectiterator.cpp b/src/qml/jsruntime/qv4objectiterator.cpp
index 338398c0d8..8fdf281c7f 100644
--- a/src/qml/jsruntime/qv4objectiterator.cpp
+++ b/src/qml/jsruntime/qv4objectiterator.cpp
@@ -102,7 +102,7 @@ Value ObjectIterator::nextPropertyName(Value *value)
         return Value::nullValue();
 
     if (value)
-        *value = object->getValue(p, attrs);
+        *value = Value::fromReturnedValue(object->getValue(p, attrs));
 
     if (name)
         return Value::fromString(name);
@@ -120,7 +120,7 @@ Value ObjectIterator::nextPropertyNameAsString(Value *value)
         return Value::nullValue();
 
     if (value)
-        *value = object->getValue(p, attrs);
+        *value = Value::fromReturnedValue(object->getValue(p, attrs));
 
     if (name)
         return Value::fromString(name);
diff --git a/src/qml/jsruntime/qv4objectproto.cpp b/src/qml/jsruntime/qv4objectproto.cpp
index 37becf8deb..1192dd5952 100644
--- a/src/qml/jsruntime/qv4objectproto.cpp
+++ b/src/qml/jsruntime/qv4objectproto.cpp
@@ -81,13 +81,14 @@ ObjectCtor::ObjectCtor(ExecutionContext *scope)
 
 ReturnedValue ObjectCtor::construct(Managed *that, CallData *callData)
 {
-    ObjectCtor *ctor = static_cast<ObjectCtor *>(that);
     ExecutionEngine *v4 = that->engine();
+    Scope scope(v4);
+    ObjectCtor *ctor = static_cast<ObjectCtor *>(that);
     if (!callData->argc || callData->args[0].isUndefined() || callData->args[0].isNull()) {
         Object *obj = v4->newObject();
-        Value proto = ctor->get(v4->id_prototype);
-        if (proto.isObject())
-            obj->setPrototype(proto.objectValue());
+        Scoped<Object> proto(scope, ctor->get(v4->id_prototype));
+        if (!!proto)
+            obj->setPrototype(proto.getPointer());
         return Value::fromObject(obj).asReturnedValue();
     }
     return Value::fromReturnedValue(__qmljs_to_object(v4->current, ValueRef(&callData->args[0]))).asReturnedValue();
@@ -221,7 +222,7 @@ Value ObjectPrototype::method_defineProperties(SimpleCallContext *ctx)
             break;
         Property n;
         PropertyAttributes nattrs;
-        toPropertyDescriptor(ctx, o->getValue(pd, attrs), &n, &nattrs);
+        toPropertyDescriptor(ctx, Value::fromReturnedValue(o->getValue(pd, attrs)), &n, &nattrs);
         bool ok;
         if (name)
             ok = O.objectValue()->__defineOwnProperty__(ctx, name, n, nattrs);
@@ -383,8 +384,7 @@ Value ObjectPrototype::method_toLocaleString(SimpleCallContext *ctx)
 {
     Scope scope(ctx);
     Object *o = ctx->thisObject.toObject(ctx);
-    Value ts = o->get(ctx->engine->newString(QStringLiteral("toString")));
-    FunctionObject *f = ts.asFunctionObject();
+    Scoped<FunctionObject> f(scope, o->get(ctx->engine->newString(QStringLiteral("toString"))));
     if (!f)
         ctx->throwTypeError();
     ScopedCallData callData(scope, 0);
@@ -514,6 +514,7 @@ void ObjectPrototype::toPropertyDescriptor(ExecutionContext *ctx, Value v, Prope
     if (!v.isObject())
         ctx->throwTypeError();
 
+    Scope scope(ctx);
     Object *o = v.objectValue();
 
     attrs->clear();
@@ -521,17 +522,17 @@ void ObjectPrototype::toPropertyDescriptor(ExecutionContext *ctx, Value v, Prope
     desc->setSetter(0);
 
     if (o->__hasProperty__(ctx->engine->id_enumerable))
-        attrs->setEnumerable(o->get(ctx->engine->id_enumerable).toBoolean());
+        attrs->setEnumerable(Value::fromReturnedValue(o->get(ctx->engine->id_enumerable)).toBoolean());
 
     if (o->__hasProperty__(ctx->engine->id_configurable))
-        attrs->setConfigurable(o->get(ctx->engine->id_configurable).toBoolean());
+        attrs->setConfigurable(Value::fromReturnedValue(o->get(ctx->engine->id_configurable)).toBoolean());
 
     if (o->__hasProperty__(ctx->engine->id_get)) {
-        Value get = o->get(ctx->engine->id_get);
-        FunctionObject *f = get.asFunctionObject();
+        ScopedValue get(scope, o->get(ctx->engine->id_get));
+        FunctionObject *f = get->asFunctionObject();
         if (f) {
             desc->setGetter(f);
-        } else if (get.isUndefined()) {
+        } else if (get->isUndefined()) {
             desc->setGetter((FunctionObject *)0x1);
         } else {
             ctx->throwTypeError();
@@ -540,11 +541,11 @@ void ObjectPrototype::toPropertyDescriptor(ExecutionContext *ctx, Value v, Prope
     }
 
     if (o->__hasProperty__(ctx->engine->id_set)) {
-        Value set = o->get(ctx->engine->id_set);
-        FunctionObject *f = set.asFunctionObject();
+        ScopedValue set(scope, o->get(ctx->engine->id_set));
+        FunctionObject *f = set->asFunctionObject();
         if (f) {
             desc->setSetter(f);
-        } else if (set.isUndefined()) {
+        } else if (set->isUndefined()) {
             desc->setSetter((FunctionObject *)0x1);
         } else {
             ctx->throwTypeError();
@@ -555,7 +556,7 @@ void ObjectPrototype::toPropertyDescriptor(ExecutionContext *ctx, Value v, Prope
     if (o->__hasProperty__(ctx->engine->id_writable)) {
         if (attrs->isAccessor())
             ctx->throwTypeError();
-        attrs->setWritable(o->get(ctx->engine->id_writable).toBoolean());
+        attrs->setWritable(Value::fromReturnedValue(o->get(ctx->engine->id_writable)).toBoolean());
         // writable forces it to be a data descriptor
         desc->value = Value::undefinedValue();
     }
@@ -563,7 +564,7 @@ void ObjectPrototype::toPropertyDescriptor(ExecutionContext *ctx, Value v, Prope
     if (o->__hasProperty__(ctx->engine->id_value)) {
         if (attrs->isAccessor())
             ctx->throwTypeError();
-        desc->value = o->get(ctx->engine->id_value);
+        desc->value = Value::fromReturnedValue(o->get(ctx->engine->id_value));
         attrs->setType(PropertyAttributes::Data);
     }
 
diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index 2f3301e298..da05fe2f9e 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -311,7 +311,7 @@ Value QObjectWrapper::getQmlProperty(ExecutionContext *ctx, QQmlContextData *qml
                 }
             }
         }
-        return QV4::Object::get(this, name, hasProperty);
+        return QV4::Value::fromReturnedValue(QV4::Object::get(this, name, hasProperty));
     }
 
     QQmlData::flushPendingBinding(m_object, result->coreIndex);
@@ -340,8 +340,8 @@ Value QObjectWrapper::getQmlProperty(ExecutionContext *ctx, QQmlContextData *qml
 
             QV4::String *connect = ctx->engine->newIdentifier(QStringLiteral("connect"));
             QV4::String *disconnect = ctx->engine->newIdentifier(QStringLiteral("disconnect"));
-            handler->put(connect, ctx->engine->functionClass->prototype->get(connect));
-            handler->put(disconnect, ctx->engine->functionClass->prototype->get(disconnect));
+            handler->put(connect, QV4::Value::fromReturnedValue(ctx->engine->functionClass->prototype->get(connect)));
+            handler->put(disconnect, QV4::Value::fromReturnedValue(ctx->engine->functionClass->prototype->get(disconnect)));
 
             return QV4::Value::fromObject(handler);
         } else {
@@ -601,12 +601,12 @@ QV4::Value QObjectWrapper::create(ExecutionEngine *engine, QQmlData *ddata, QObj
     return Value::fromObject(new (engine->memoryManager) QV4::QObjectWrapper(engine, object));
 }
 
-QV4::Value QObjectWrapper::get(Managed *m, String *name, bool *hasProperty)
+QV4::ReturnedValue QObjectWrapper::get(Managed *m, String *name, bool *hasProperty)
 {
     QObjectWrapper *that = static_cast<QObjectWrapper*>(m);
     ExecutionEngine *v4 = m->engine();
     QQmlContextData *qmlContext = QV4::QmlContextWrapper::callingContext(v4);
-    return that->getQmlProperty(v4->current, qmlContext, name, IgnoreRevision, hasProperty, /*includeImports*/ true);
+    return that->getQmlProperty(v4->current, qmlContext, name, IgnoreRevision, hasProperty, /*includeImports*/ true).asReturnedValue();
 }
 
 void QObjectWrapper::put(Managed *m, String *name, const Value &value)
@@ -655,7 +655,7 @@ Property *QObjectWrapper::advanceIterator(Managed *m, ObjectIterator *it, String
         ++it->arrayIndex;
         if (attributes)
             *attributes = QV4::Attr_Data;
-        it->tmpDynamicProperty.value = that->get(*name);
+        it->tmpDynamicProperty.value = QV4::Value::fromReturnedValue(that->get(*name));
         return &it->tmpDynamicProperty;
     }
     const int methodCount = mo->methodCount();
@@ -664,7 +664,7 @@ Property *QObjectWrapper::advanceIterator(Managed *m, ObjectIterator *it, String
         ++it->arrayIndex;
         if (attributes)
             *attributes = QV4::Attr_Data;
-        it->tmpDynamicProperty.value = that->get(*name);
+        it->tmpDynamicProperty.value = QV4::Value::fromReturnedValue(that->get(*name));
         return &it->tmpDynamicProperty;
     }
     return QV4::Object::advanceIterator(m, it, name, index, attributes);
diff --git a/src/qml/jsruntime/qv4qobjectwrapper_p.h b/src/qml/jsruntime/qv4qobjectwrapper_p.h
index 4034e14cf5..716e72d375 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper_p.h
+++ b/src/qml/jsruntime/qv4qobjectwrapper_p.h
@@ -105,7 +105,7 @@ private:
     String *m_destroy;
     String *m_toString;
 
-    static Value get(Managed *m, String *name, bool *hasProperty);
+    static ReturnedValue get(Managed *m, String *name, bool *hasProperty);
     static void put(Managed *m, String *name, const Value &value);
     static PropertyAttributes query(const Managed *, String *name);
     static Property *advanceIterator(Managed *m, ObjectIterator *it, String **name, uint *index, PropertyAttributes *attributes);
diff --git a/src/qml/jsruntime/qv4regexp.cpp b/src/qml/jsruntime/qv4regexp.cpp
index ab01ce7650..7483abd2ae 100644
--- a/src/qml/jsruntime/qv4regexp.cpp
+++ b/src/qml/jsruntime/qv4regexp.cpp
@@ -136,9 +136,9 @@ void RegExp::markObjects(Managed *that)
 {
 }
 
-Value RegExp::get(Managed *m, String *name, bool *hasProperty)
+ReturnedValue RegExp::get(Managed *, String *, bool *)
 {
-    return Value::undefinedValue();
+    return Value::undefinedValue().asReturnedValue();
 }
 
 Value RegExp::getIndexed(Managed *m, uint index, bool *hasProperty)
diff --git a/src/qml/jsruntime/qv4regexp_p.h b/src/qml/jsruntime/qv4regexp_p.h
index 6edbd4b2ad..3032952ec5 100644
--- a/src/qml/jsruntime/qv4regexp_p.h
+++ b/src/qml/jsruntime/qv4regexp_p.h
@@ -111,7 +111,7 @@ public:
 protected:
     static void destroy(Managed *that);
     static void markObjects(Managed *that);
-    static Value get(Managed *m, String *name, bool *hasProperty);
+    static ReturnedValue get(Managed *, String *, bool *);
     static Value getIndexed(Managed *m, uint index, bool *hasProperty);
     static void put(Managed *m, String *name, const Value &value);
     static void putIndexed(Managed *m, uint index, const Value &value);
diff --git a/src/qml/jsruntime/qv4regexpobject.cpp b/src/qml/jsruntime/qv4regexpobject.cpp
index 4ad8c4a0a1..3dcd49f6a5 100644
--- a/src/qml/jsruntime/qv4regexpobject.cpp
+++ b/src/qml/jsruntime/qv4regexpobject.cpp
@@ -206,7 +206,8 @@ QString RegExpObject::toString() const
 
 QString RegExpObject::source() const
 {
-    return const_cast<RegExpObject *>(this)->get(internalClass->engine->newIdentifier(QStringLiteral("source"))).stringValue()->toQString();
+    Value s = Value::fromReturnedValue(const_cast<RegExpObject *>(this)->get(internalClass->engine->newIdentifier(QStringLiteral("source"))));
+    return s.stringValue()->toQString();
 }
 
 uint RegExpObject::flags() const
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index a6257958b4..31f477bedd 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -692,7 +692,7 @@ ReturnedValue __qmljs_get_element(ExecutionContext *ctx, const ValueRef object,
     }
 
     String *name = index->toString(ctx);
-    return o->get(name).asReturnedValue();
+    return o->get(name);
 }
 
 void __qmljs_set_element(ExecutionContext *ctx, const ValueRef object, const ValueRef index, const ValueRef value)
@@ -769,7 +769,7 @@ ReturnedValue __qmljs_get_property(ExecutionContext *ctx, const ValueRef object,
     Value res;
     Managed *m = object->asManaged();
     if (m)
-        return m->get(name).asReturnedValue();
+        return m->get(name);
 
     if (object->isNullOrUndefined()) {
         QString message = QStringLiteral("Cannot read property '%1' of %2").arg(name->toQString()).arg(object->toQStringNoThrow());
@@ -777,7 +777,7 @@ ReturnedValue __qmljs_get_property(ExecutionContext *ctx, const ValueRef object,
     }
 
     m = __qmljs_convert_to_object(ctx, object);
-    return m->get(name).asReturnedValue();
+    return m->get(name);
 }
 
 ReturnedValue __qmljs_get_activation_property(ExecutionContext *ctx, String *name)
@@ -974,6 +974,7 @@ ReturnedValue __qmljs_call_activation_property(ExecutionContext *context, String
 
 ReturnedValue __qmljs_call_property(ExecutionContext *context, String *name, CallDataRef callData)
 {
+    Scope scope(context);
     Managed *baseObject = callData->thisObject.asManaged();
     if (!baseObject) {
         if (callData->thisObject.isNullOrUndefined()) {
@@ -985,7 +986,7 @@ ReturnedValue __qmljs_call_property(ExecutionContext *context, String *name, Cal
         callData->thisObject = Value::fromObject(static_cast<Object *>(baseObject));
     }
 
-    FunctionObject *o = baseObject->get(name).asFunctionObject();
+    Scoped<FunctionObject> o(scope, baseObject->get(name));
     if (!o) {
         QString error = QString("Property '%1' of object %2 is not a function").arg(name->toQString(), callData->thisObject.toQStringNoThrow());
         context->throwTypeError(error);
@@ -1010,10 +1011,11 @@ ReturnedValue __qmljs_call_property_lookup(ExecutionContext *context, uint index
 
 ReturnedValue __qmljs_call_element(ExecutionContext *context, const ValueRef index, CallDataRef callData)
 {
+    Scope scope(context);
     Object *baseObject = callData->thisObject.toObject(context);
     callData->thisObject = Value::fromObject(baseObject);
 
-    Object *o = baseObject->get(index->toString(context)).asObject();
+    Scoped<Object> o(scope, baseObject->get(index->toString(context)));
     if (!o)
         context->throwTypeError();
 
@@ -1069,10 +1071,10 @@ ReturnedValue __qmljs_construct_value(ExecutionContext *context, const ValueRef
 
 ReturnedValue __qmljs_construct_property(ExecutionContext *context, const ValueRef base, String *name, CallDataRef callData)
 {
+    Scope scope(context);
     Object *thisObject = base->toObject(context);
 
-    Value func = thisObject->get(name);
-    Object *f = func.asObject();
+    Scoped<Object> f(scope, thisObject->get(name));
     if (!f)
         context->throwTypeError();
 
diff --git a/src/qml/jsruntime/qv4scopedvalue_p.h b/src/qml/jsruntime/qv4scopedvalue_p.h
index 7bb98e7a62..4fe0362c46 100644
--- a/src/qml/jsruntime/qv4scopedvalue_p.h
+++ b/src/qml/jsruntime/qv4scopedvalue_p.h
@@ -170,6 +170,87 @@ struct ScopedValue
     Value *ptr;
 };
 
+template<typename T>
+struct Scoped
+{
+    Scoped(const Scope &scope)
+    {
+        ptr = scope.engine->jsStackTop++;
+#ifndef QT_NO_DEBUG
+        ++scope.size;
+#endif
+    }
+
+    Scoped(const Scope &scope, const Value &v)
+    {
+        ptr = scope.engine->jsStackTop++;
+        if (T::cast(v))
+            *ptr = v;
+        else
+            *ptr = QV4::Value::undefinedValue();
+#ifndef QT_NO_DEBUG
+        ++scope.size;
+#endif
+    }
+
+    Scoped(const Scope &scope, const ReturnedValue &v)
+    {
+        ptr = scope.engine->jsStackTop++;
+        if (T::cast(QV4::Value::fromReturnedValue(v)))
+            ptr->val = v;
+        else
+            *ptr = QV4::Value::undefinedValue();
+#ifndef QT_NO_DEBUG
+        ++scope.size;
+#endif
+    }
+
+    Scoped<T> &operator=(const Value &v) {
+        if (T::cast(v))
+            *ptr = v;
+        else
+            *ptr = QV4::Value::undefinedValue();
+        return *this;
+    }
+
+    Scoped<T> &operator=(const ReturnedValue &v) {
+        if (T::cast(QV4::Value::fromReturnedValue(v)))
+            ptr->val = v;
+        else
+            *ptr = QV4::Value::undefinedValue();
+        return *this;
+    }
+
+    Scoped<T> &operator=(const Scoped<T> &other) {
+        *ptr = *other.ptr;
+        return *this;
+    }
+
+    T *operator->() {
+        return static_cast<T *>(ptr->asManaged());
+    }
+
+//    const Value *operator->() const {
+//        return T::cast(*ptr);
+//    }
+
+    bool operator!() const {
+        return !ptr->asManaged();
+    }
+
+    T *getPointer() {
+        return static_cast<T *>(ptr->asManaged());
+    }
+
+    Value asValue() const {
+        return *ptr;
+    }
+
+    ReturnedValue asReturnedValue() const { return ptr->val; }
+
+    Value *ptr;
+};
+
 struct ScopedCallData {
     ScopedCallData(Scope &scope, int argc)
     {
diff --git a/src/qml/jsruntime/qv4serialize.cpp b/src/qml/jsruntime/qv4serialize.cpp
index f7389dc6d7..b183baf0c2 100644
--- a/src/qml/jsruntime/qv4serialize.cpp
+++ b/src/qml/jsruntime/qv4serialize.cpp
@@ -150,6 +150,8 @@ static inline void *popPtr(const char *&data)
 void Serialize::serialize(QByteArray &data, const QV4::Value &v, QV8Engine *engine)
 {
     QV4::ExecutionEngine *v4 = QV8Engine::getV4(engine);
+    QV4::Scope scope(v4);
+
     if (v.isEmpty()) {
     } else if (v.isUndefined()) {
         push(data, valueheader(WorkerUndefined));
@@ -240,7 +242,7 @@ void Serialize::serialize(QByteArray &data, const QV4::Value &v, QV8Engine *engi
 
         if (o->isListType()) {
             // valid sequence.  we generate a length (sequence length + 1 for the sequence type)
-            uint32_t seqLength = o->get(v4->id_length).toUInt32();
+            uint32_t seqLength = ScopedValue(scope, o->get(v4->id_length))->toUInt32();
             uint32_t length = seqLength + 1;
             if (length > 0xFFFFFF) {
                 push(data, valueheader(WorkerUndefined));
@@ -264,14 +266,13 @@ void Serialize::serialize(QByteArray &data, const QV4::Value &v, QV8Engine *engi
         }
         push(data, valueheader(WorkerObject, length));
 
-        QV4::ExecutionEngine *v4 = QV8Engine::getV4(engine);
+        QV4::ScopedValue val(scope);
         for (quint32 ii = 0; ii < length; ++ii) {
             QV4::String *s = properties->getIndexed(ii).asString();
             serialize(data, QV4::Value::fromString(s), engine);
 
             bool hasCaught = false;
             QV4::ExecutionContext *ctx = v4->current;
-            QV4::Value val = QV4::Value::undefinedValue();
             try {
                 val = o->get(s);
             } catch (QV4::Exception &e) {
diff --git a/src/qml/jsruntime/qv4string.cpp b/src/qml/jsruntime/qv4string.cpp
index 11d3100180..7342b27fb8 100644
--- a/src/qml/jsruntime/qv4string.cpp
+++ b/src/qml/jsruntime/qv4string.cpp
@@ -129,21 +129,21 @@ void String::destroy(Managed *that)
     static_cast<String*>(that)->~String();
 }
 
-Value String::get(Managed *m, String *name, bool *hasProperty)
+ReturnedValue String::get(Managed *m, String *name, bool *hasProperty)
 {
     String *that = static_cast<String *>(m);
     ExecutionEngine *v4 = m->engine();
     if (name == v4->id_length) {
         if (hasProperty)
             *hasProperty = true;
-        return Value::fromInt32(that->_text.length());
+        return Value::fromInt32(that->_text.length()).asReturnedValue();
     }
     PropertyAttributes attrs;
     Property *pd = v4->stringClass->prototype->__getPropertyDescriptor__(name, &attrs);
     if (!pd || attrs.isGeneric()) {
         if (hasProperty)
             *hasProperty = false;
-        return Value::undefinedValue();
+        return Value::undefinedValue().asReturnedValue();
     }
     if (hasProperty)
         *hasProperty = true;
@@ -168,7 +168,7 @@ Value String::getIndexed(Managed *m, uint index, bool *hasProperty)
     }
     if (hasProperty)
         *hasProperty = true;
-    return engine->stringClass->prototype->getValue(Value::fromString(that), pd, attrs);
+    return Value::fromReturnedValue(engine->stringClass->prototype->getValue(Value::fromString(that), pd, attrs));
 }
 
 void String::put(Managed *m, String *name, const Value &value)
diff --git a/src/qml/jsruntime/qv4string_p.h b/src/qml/jsruntime/qv4string_p.h
index 96e3393700..49914c1485 100644
--- a/src/qml/jsruntime/qv4string_p.h
+++ b/src/qml/jsruntime/qv4string_p.h
@@ -119,6 +119,10 @@ struct Q_QML_EXPORT String : public Managed {
         return _text.length();
     }
 
+    static String *cast(const Value &v) {
+        return v.asString();
+    }
+
     ReturnedValue asReturnedValue() { return Value::fromString(this).asReturnedValue(); }
 
     QString _text;
@@ -128,7 +132,7 @@ struct Q_QML_EXPORT String : public Managed {
 
 protected:
     static void destroy(Managed *);
-    static Value get(Managed *m, String *name, bool *hasProperty);
+    static ReturnedValue get(Managed *m, String *name, bool *hasProperty);
     static Value getIndexed(Managed *m, uint index, bool *hasProperty);
     static void put(Managed *m, String *name, const Value &value);
     static void putIndexed(Managed *m, uint index, const Value &value);
diff --git a/src/qml/jsruntime/qv4stringobject.cpp b/src/qml/jsruntime/qv4stringobject.cpp
index 8df40ea488..7a5252f3ad 100644
--- a/src/qml/jsruntime/qv4stringobject.cpp
+++ b/src/qml/jsruntime/qv4stringobject.cpp
@@ -369,7 +369,7 @@ Value StringPrototype::method_match(SimpleCallContext *context)
     bool global = rx->global;
 
     // ### use the standard builtin function, not the one that might be redefined in the proto
-    FunctionObject *exec = context->engine->regExpClass->prototype->get(context->engine->newString(QStringLiteral("exec")), 0).asFunctionObject();
+    Scoped<FunctionObject> exec(scope, context->engine->regExpClass->prototype->get(context->engine->newString(QStringLiteral("exec")), 0));
 
     ScopedCallData callData(scope, 1);
     callData->thisObject = Value::fromObject(rx);
@@ -385,12 +385,14 @@ Value StringPrototype::method_match(SimpleCallContext *context)
     uint n = 0;
     ScopedValue result(scope);
     ScopedValue matchStr(scope);
+    ScopedValue index(scope);
     while (1) {
         result = exec->call(callData);
         if (result->isNull())
             break;
         assert(result->isObject());
-        double thisIndex = rx->get(lastIndex, 0).toInteger();
+        index = rx->get(lastIndex, 0);
+        double thisIndex = index->toInteger();
         if (previousLastIndex == thisIndex) {
             previousLastIndex = thisIndex + 1;
             rx->put(lastIndex, Value::fromDouble(previousLastIndex));
diff --git a/src/qml/jsruntime/qv4value.cpp b/src/qml/jsruntime/qv4value.cpp
index d0857556b6..384df32601 100644
--- a/src/qml/jsruntime/qv4value.cpp
+++ b/src/qml/jsruntime/qv4value.cpp
@@ -316,12 +316,6 @@ Object *Value::toObject(ExecutionContext *ctx) const
 }
 
 
-Value Value::property(ExecutionContext *ctx, String *name) const
-{
-    return isObject() ? objectValue()->get(name) : undefinedValue();
-}
-
-
 PersistentValue::PersistentValue(const Value &val)
     : d(new PersistentValuePrivate(val))
 {
diff --git a/src/qml/jsruntime/qv4value_def_p.h b/src/qml/jsruntime/qv4value_def_p.h
index c55ad0c6f7..866e5e7e7d 100644
--- a/src/qml/jsruntime/qv4value_def_p.h
+++ b/src/qml/jsruntime/qv4value_def_p.h
@@ -268,8 +268,6 @@ struct Q_QML_EXPORT Value
     uint asArrayIndex() const;
     uint asArrayLength(bool *ok) const;
 
-    Value property(ExecutionContext *ctx, String *name) const;
-
     inline ExecutionEngine *engine() const;
 
     ReturnedValue asReturnedValue() const { return val; }
diff --git a/src/qml/qml/qqmlcontextwrapper.cpp b/src/qml/qml/qqmlcontextwrapper.cpp
index bd0b211403..f84f288770 100644
--- a/src/qml/qml/qqmlcontextwrapper.cpp
+++ b/src/qml/qml/qqmlcontextwrapper.cpp
@@ -124,21 +124,22 @@ void QmlContextWrapper::takeContextOwnership(const Value &qmlglobal)
 }
 
 
-Value QmlContextWrapper::get(Managed *m, String *name, bool *hasProperty)
+ReturnedValue QmlContextWrapper::get(Managed *m, String *name, bool *hasProperty)
 {
-    QmlContextWrapper *resource = m->as<QmlContextWrapper>();
     QV4::ExecutionEngine *v4 = m->engine();
+    QV4::Scope scope(v4);
+    QmlContextWrapper *resource = m->as<QmlContextWrapper>();
     if (!resource)
         v4->current->throwTypeError();
 
     // In V8 the JS global object would come _before_ the QML global object,
     // so simulate that here.
     bool hasProp;
-    QV4::Value result = v4->globalObject->get(name, &hasProp);
+    QV4::ScopedValue result(scope, v4->globalObject->get(name, &hasProp));
     if (hasProp) {
         if (hasProperty)
             *hasProperty = hasProp;
-        return result;
+        return result.asReturnedValue();
     }
 
     if (resource->isNullWrapper)
@@ -151,7 +152,7 @@ Value QmlContextWrapper::get(Managed *m, String *name, bool *hasProperty)
     if (hasProp) {
         if (hasProperty)
             *hasProperty = hasProp;
-        return result;
+        return result.asReturnedValue();
     }
 
     // Its possible we could delay the calculation of the "actual" context (in the case
@@ -162,7 +163,7 @@ Value QmlContextWrapper::get(Managed *m, String *name, bool *hasProperty)
     if (!context) {
         if (hasProperty)
             *hasProperty = true;
-        return result;
+        return result.asReturnedValue();
     }
 
     // Search type (attached property/enum/imported scripts) names
@@ -187,13 +188,13 @@ Value QmlContextWrapper::get(Managed *m, String *name, bool *hasProperty)
             if (r.scriptIndex != -1) {
                 int index = r.scriptIndex;
                 if (index < context->importedScripts.count())
-                    return context->importedScripts.at(index).value();
+                    return context->importedScripts.at(index).value().asReturnedValue();
                 else
-                    return QV4::Value::undefinedValue();
+                    return QV4::Value::undefinedValue().asReturnedValue();
             } else if (r.type) {
-                return QmlTypeWrapper::create(engine, scopeObject, r.type);
+                return QmlTypeWrapper::create(engine, scopeObject, r.type).asReturnedValue();
             } else if (r.importNamespace) {
-                return QmlTypeWrapper::create(engine, scopeObject, context->imports, r.importNamespace);
+                return QmlTypeWrapper::create(engine, scopeObject, context->imports, r.importNamespace).asReturnedValue();
             }
             Q_ASSERT(!"Unreachable");
         }
@@ -215,7 +216,7 @@ Value QmlContextWrapper::get(Managed *m, String *name, bool *hasProperty)
                     ep->captureProperty(&context->idValues[propertyIdx].bindings);
                     if (hasProperty)
                         *hasProperty = true;
-                    return QV4::QObjectWrapper::wrap(v4, context->idValues[propertyIdx]);
+                    return QV4::QObjectWrapper::wrap(v4, context->idValues[propertyIdx]).asReturnedValue();
                 } else {
 
                     QQmlContextPrivate *cp = context->asQQmlContextPrivate();
@@ -230,9 +231,9 @@ Value QmlContextWrapper::get(Managed *m, String *name, bool *hasProperty)
                         QQmlListProperty<QObject> prop(context->asQQmlContext(), (void*) qintptr(propertyIdx),
                                                                QQmlContextPrivate::context_count,
                                                                QQmlContextPrivate::context_at);
-                        return QmlListWrapper::create(engine, prop, qMetaTypeId<QQmlListProperty<QObject> >());
+                        return QmlListWrapper::create(engine, prop, qMetaTypeId<QQmlListProperty<QObject> >()).asReturnedValue();
                     } else {
-                        return engine->fromVariant(cp->propertyValues.at(propertyIdx));
+                        return engine->fromVariant(cp->propertyValues.at(propertyIdx)).asReturnedValue();
                     }
                 }
             }
@@ -245,7 +246,7 @@ Value QmlContextWrapper::get(Managed *m, String *name, bool *hasProperty)
             if (hasProp) {
                 if (hasProperty)
                     *hasProperty = true;
-                return result;
+                return result.asReturnedValue();
             }
         }
         scopeObject = 0;
@@ -254,11 +255,11 @@ Value QmlContextWrapper::get(Managed *m, String *name, bool *hasProperty)
         // Search context object
         if (context->contextObject) {
             bool hasProp = false;
-            QV4::Value result = QV4::QObjectWrapper::getQmlProperty(v4->current, context, context->contextObject, name, QV4::QObjectWrapper::CheckRevision, &hasProp);
+            result = QV4::QObjectWrapper::getQmlProperty(v4->current, context, context->contextObject, name, QV4::QObjectWrapper::CheckRevision, &hasProp);
             if (hasProp) {
                 if (hasProperty)
                     *hasProperty = true;
-                return result;
+                return result.asReturnedValue();
             }
         }
 
@@ -267,7 +268,7 @@ Value QmlContextWrapper::get(Managed *m, String *name, bool *hasProperty)
 
     expressionContext->unresolvedNames = true;
 
-    return Value::undefinedValue();
+    return Value::undefinedValue().asReturnedValue();
 }
 
 void QmlContextWrapper::put(Managed *m, String *name, const Value &value)
diff --git a/src/qml/qml/qqmlcontextwrapper_p.h b/src/qml/qml/qqmlcontextwrapper_p.h
index 0f44952567..0ed933014b 100644
--- a/src/qml/qml/qqmlcontextwrapper_p.h
+++ b/src/qml/qml/qqmlcontextwrapper_p.h
@@ -82,7 +82,7 @@ struct Q_QML_EXPORT QmlContextWrapper : Object
 
     void setReadOnly(bool b) { readOnly = b; }
 
-    static Value get(Managed *m, String *name, bool *hasProperty);
+    static ReturnedValue get(Managed *m, String *name, bool *hasProperty);
     static void put(Managed *m, String *name, const Value &value);
     static void destroy(Managed *that);
 
diff --git a/src/qml/qml/qqmljavascriptexpression.cpp b/src/qml/qml/qqmljavascriptexpression.cpp
index 4f67a1dd28..12f594ee5f 100644
--- a/src/qml/qml/qqmljavascriptexpression.cpp
+++ b/src/qml/qml/qqmljavascriptexpression.cpp
@@ -312,7 +312,7 @@ void QQmlJavaScriptExpression::exceptionToError(const QV4::Exception &e, QQmlErr
     }
     QV4::ErrorObject *errorObj = e.value().asErrorObject();
     if (errorObj && errorObj->asSyntaxError())
-        error.setDescription(errorObj->get(errorObj->engine()->newString("message")).toQStringNoThrow());
+        error.setDescription(QV4::Value::fromReturnedValue(errorObj->get(errorObj->engine()->newString("message"))).toQStringNoThrow());
     else
         error.setDescription(e.value().toQStringNoThrow());
 }
diff --git a/src/qml/qml/qqmllistwrapper.cpp b/src/qml/qml/qqmllistwrapper.cpp
index 1c1386d5b7..749702b357 100644
--- a/src/qml/qml/qqmllistwrapper.cpp
+++ b/src/qml/qml/qqmllistwrapper.cpp
@@ -98,7 +98,7 @@ QVariant QmlListWrapper::toVariant() const
 }
 
 
-Value QmlListWrapper::get(Managed *m, String *name, bool *hasProperty)
+ReturnedValue QmlListWrapper::get(Managed *m, String *name, bool *hasProperty)
 {
     QV4::ExecutionEngine *v4 = m->engine();
     QmlListWrapper *w = m->as<QmlListWrapper>();
@@ -107,12 +107,12 @@ Value QmlListWrapper::get(Managed *m, String *name, bool *hasProperty)
 
     if (name == v4->id_length && !w->object.isNull()) {
         quint32 count = w->property.count ? w->property.count(&w->property) : 0;
-        return Value::fromUInt32(count);
+        return Value::fromUInt32(count).asReturnedValue();
     }
 
     uint idx = name->asArrayIndex();
     if (idx != UINT_MAX)
-        return getIndexed(m, idx, hasProperty);
+        return getIndexed(m, idx, hasProperty).asReturnedValue();
 
     return Object::get(m, name, hasProperty);
 }
diff --git a/src/qml/qml/qqmllistwrapper_p.h b/src/qml/qml/qqmllistwrapper_p.h
index c87b9b22d5..797e39bedd 100644
--- a/src/qml/qml/qqmllistwrapper_p.h
+++ b/src/qml/qml/qqmllistwrapper_p.h
@@ -81,7 +81,7 @@ public:
 
     QVariant toVariant() const;
 
-    static Value get(Managed *m, String *name, bool *hasProperty);
+    static ReturnedValue get(Managed *m, String *name, bool *hasProperty);
     static Value getIndexed(Managed *m, uint index, bool *hasProperty);
     static void put(Managed *m, String *name, const Value &value);
     static Property *advanceIterator(Managed *m, ObjectIterator *it, String **name, uint *index, PropertyAttributes *attributes);
diff --git a/src/qml/qml/qqmltypewrapper.cpp b/src/qml/qml/qqmltypewrapper.cpp
index 33b8fb8e7a..8f05a877ef 100644
--- a/src/qml/qml/qqmltypewrapper.cpp
+++ b/src/qml/qml/qqmltypewrapper.cpp
@@ -112,7 +112,7 @@ Value QmlTypeWrapper::create(QV8Engine *v8, QObject *o, QQmlTypeNameCache *t, co
 }
 
 
-Value QmlTypeWrapper::get(Managed *m, String *name, bool *hasProperty)
+ReturnedValue QmlTypeWrapper::get(Managed *m, String *name, bool *hasProperty)
 {
     QmlTypeWrapper *w = m->as<QmlTypeWrapper>();
     QV4::ExecutionEngine *v4 = m->engine();
@@ -149,13 +149,13 @@ Value QmlTypeWrapper::get(Managed *m, String *name, bool *hasProperty)
                             bool ok;
                             int value = e.keyToValue(enumName.constData(), &ok);
                             if (ok)
-                                return QV4::Value::fromInt32(value);
+                                return QV4::Value::fromInt32(value).asReturnedValue();
                         }
                     }
                 }
 
                 // check for property.
-                return QV4::QObjectWrapper::getQmlProperty(v4->current, context, qobjectSingleton, name, QV4::QObjectWrapper::IgnoreRevision, hasProperty);
+                return QV4::QObjectWrapper::getQmlProperty(v4->current, context, qobjectSingleton, name, QV4::QObjectWrapper::IgnoreRevision, hasProperty).asReturnedValue();
             } else if (!siinfo->scriptApi(e).isUndefined()) {
                 QV4::ExecutionEngine *engine = QV8Engine::getV4(v8engine);
                 // NOTE: if used in a binding, changes will not trigger re-evaluation since non-NOTIFYable.
@@ -172,14 +172,14 @@ Value QmlTypeWrapper::get(Managed *m, String *name, bool *hasProperty)
                 bool ok = false;
                 int value = type->enumValue(name, &ok);
                 if (ok)
-                    return QV4::Value::fromInt32(value);
+                    return QV4::Value::fromInt32(value).asReturnedValue();
 
                 // Fall through to base implementation
 
             } else if (w->object) {
                 QObject *ao = qmlAttachedPropertiesObjectById(type->attachedPropertiesId(), object);
                 if (ao)
-                    return QV4::QObjectWrapper::getQmlProperty(v4->current, context, ao, name, QV4::QObjectWrapper::IgnoreRevision, hasProperty);
+                    return QV4::QObjectWrapper::getQmlProperty(v4->current, context, ao, name, QV4::QObjectWrapper::IgnoreRevision, hasProperty).asReturnedValue();
 
                 // Fall through to base implementation
             }
@@ -196,16 +196,16 @@ Value QmlTypeWrapper::get(Managed *m, String *name, bool *hasProperty)
         if (r.isValid()) {
             QQmlContextData *context = v8engine->callingContext();
             if (r.type) {
-                return create(w->v8, object, r.type, w->mode);
+                return create(w->v8, object, r.type, w->mode).asReturnedValue();
             } else if (r.scriptIndex != -1) {
                 int index = r.scriptIndex;
                 if (index < context->importedScripts.count())
-                    return context->importedScripts.at(index).value();
+                    return context->importedScripts.at(index).value().asReturnedValue();
             } else if (r.importNamespace) {
-                return create(w->v8, object, context->imports, r.importNamespace);
+                return create(w->v8, object, context->imports, r.importNamespace).asReturnedValue();
             }
 
-            return QV4::Value::undefinedValue();
+            return QV4::Value::undefinedValue().asReturnedValue();
 
         }
 
diff --git a/src/qml/qml/qqmltypewrapper_p.h b/src/qml/qml/qqmltypewrapper_p.h
index 944621b1d6..c545e1cc3b 100644
--- a/src/qml/qml/qqmltypewrapper_p.h
+++ b/src/qml/qml/qqmltypewrapper_p.h
@@ -82,7 +82,7 @@ public:
     static QV4::Value create(QV8Engine *, QObject *, QQmlTypeNameCache *, const void *, TypeNameMode = IncludeEnums);
 
 
-    static Value get(Managed *m, String *name, bool *hasProperty);
+    static ReturnedValue get(Managed *m, String *name, bool *hasProperty);
     static void put(Managed *m, String *name, const Value &value);
     static PropertyAttributes query(const Managed *, String *name);
     static void destroy(Managed *that);
diff --git a/src/qml/qml/qqmlvaluetypewrapper.cpp b/src/qml/qml/qqmlvaluetypewrapper.cpp
index f494fba11f..98b2497b0d 100644
--- a/src/qml/qml/qqmlvaluetypewrapper.cpp
+++ b/src/qml/qml/qqmlvaluetypewrapper.cpp
@@ -263,7 +263,7 @@ Value QmlValueTypeWrapper::method_toString(SimpleCallContext *ctx)
     }
 }
 
-Value QmlValueTypeWrapper::get(Managed *m, String *name, bool *hasProperty)
+ReturnedValue QmlValueTypeWrapper::get(Managed *m, String *name, bool *hasProperty)
 {
     QmlValueTypeWrapper *r = m->as<QmlValueTypeWrapper>();
     QV4::ExecutionEngine *v4 = m->engine();
@@ -275,7 +275,7 @@ Value QmlValueTypeWrapper::get(Managed *m, String *name, bool *hasProperty)
         QmlValueTypeReference *reference = static_cast<QmlValueTypeReference *>(r);
 
         if (!reference->object || !readReferenceValue(reference))
-            return Value::undefinedValue();
+            return Value::undefinedValue().asReturnedValue();
 
     } else {
         Q_ASSERT(r->objectType == QmlValueTypeWrapper::Copy);
@@ -301,7 +301,7 @@ Value QmlValueTypeWrapper::get(Managed *m, String *name, bool *hasProperty)
     if (result->isFunction()) {
         // calling a Q_INVOKABLE function of a value type
         QQmlContextData *qmlContext = QV4::QmlContextWrapper::callingContext(v4);
-        return QV4::QObjectWrapper::getQmlProperty(v4->current, qmlContext, r->type, name, QV4::QObjectWrapper::IgnoreRevision);
+        return QV4::QObjectWrapper::getQmlProperty(v4->current, qmlContext, r->type, name, QV4::QObjectWrapper::IgnoreRevision).asReturnedValue();
     }
 
 #define VALUE_TYPE_LOAD(metatype, cpptype, constructor) \
@@ -309,7 +309,7 @@ Value QmlValueTypeWrapper::get(Managed *m, String *name, bool *hasProperty)
         cpptype v; \
         void *args[] = { &v, 0 }; \
         r->type->qt_metacall(QMetaObject::ReadProperty, result->coreIndex, args); \
-        return constructor(v); \
+        return constructor(v).asReturnedValue(); \
     }
 
     // These four types are the most common used by the value type wrappers
@@ -321,7 +321,7 @@ Value QmlValueTypeWrapper::get(Managed *m, String *name, bool *hasProperty)
     QVariant v(result->propType, (void *)0);
     void *args[] = { v.data(), 0 };
     r->type->qt_metacall(QMetaObject::ReadProperty, result->coreIndex, args);
-    return r->v8->fromVariant(v);
+    return r->v8->fromVariant(v).asReturnedValue();
 #undef VALUE_TYPE_ACCESSOR
 }
 
diff --git a/src/qml/qml/qqmlvaluetypewrapper_p.h b/src/qml/qml/qqmlvaluetypewrapper_p.h
index f5088a5954..aa9de3330e 100644
--- a/src/qml/qml/qqmlvaluetypewrapper_p.h
+++ b/src/qml/qml/qqmlvaluetypewrapper_p.h
@@ -83,7 +83,7 @@ public:
     bool isEqual(const QVariant& value);
 
 
-    static Value get(Managed *m, String *name, bool *hasProperty);
+    static ReturnedValue get(Managed *m, String *name, bool *hasProperty);
     static void put(Managed *m, String *name, const Value &value);
     static void destroy(Managed *that);
     static bool isEqualTo(Managed *m, Managed *other);
diff --git a/src/qml/qml/qqmlxmlhttprequest.cpp b/src/qml/qml/qqmlxmlhttprequest.cpp
index 849e226a37..212f64fcef 100644
--- a/src/qml/qml/qqmlxmlhttprequest.cpp
+++ b/src/qml/qml/qqmlxmlhttprequest.cpp
@@ -204,7 +204,7 @@ public:
     static void destroy(Managed *that) {
         that->as<NamedNodeMap>()->~NamedNodeMap();
     }
-    static Value get(Managed *m, String *name, bool *hasProperty);
+    static ReturnedValue get(Managed *m, String *name, bool *hasProperty);
     static Value getIndexed(Managed *m, uint index, bool *hasProperty);
 
     QList<NodeImpl *> list; // Only used in NamedNodeMap
@@ -235,7 +235,7 @@ public:
     static void destroy(Managed *that) {
         that->as<NodeList>()->~NodeList();
     }
-    static Value get(Managed *m, String *name, bool *hasProperty);
+    static ReturnedValue get(Managed *m, String *name, bool *hasProperty);
     static Value getIndexed(Managed *m, uint index, bool *hasProperty);
 
     // C++ API
@@ -862,7 +862,7 @@ Value NamedNodeMap::getIndexed(Managed *m, uint index, bool *hasProperty)
     return Value::undefinedValue();
 }
 
-Value NamedNodeMap::get(Managed *m, String *name, bool *hasProperty)
+ReturnedValue NamedNodeMap::get(Managed *m, String *name, bool *hasProperty)
 {
     NamedNodeMap *r = m->as<NamedNodeMap>();
     QV4::ExecutionEngine *v4 = m->engine();
@@ -871,7 +871,7 @@ Value NamedNodeMap::get(Managed *m, String *name, bool *hasProperty)
 
     name->makeIdentifier();
     if (name->isEqualTo(v4->id_length))
-        return Value::fromInt32(r->list.count());
+        return Value::fromInt32(r->list.count()).asReturnedValue();
 
     QV8Engine *engine = v4->v8Engine;
 
@@ -880,13 +880,13 @@ Value NamedNodeMap::get(Managed *m, String *name, bool *hasProperty)
         if (r->list.at(ii)->name == str) {
             if (hasProperty)
                 *hasProperty = true;
-            return Node::create(engine, r->list.at(ii));
+            return Node::create(engine, r->list.at(ii)).asReturnedValue();
         }
     }
 
     if (hasProperty)
         *hasProperty = false;
-    return Value::undefinedValue();
+    return Value::undefinedValue().asReturnedValue();
 }
 
 Value NamedNodeMap::create(QV8Engine *engine, NodeImpl *data, const QList<NodeImpl *> &list)
@@ -916,7 +916,7 @@ Value NodeList::getIndexed(Managed *m, uint index, bool *hasProperty)
     return Value::undefinedValue();
 }
 
-Value NodeList::get(Managed *m, String *name, bool *hasProperty)
+ReturnedValue NodeList::get(Managed *m, String *name, bool *hasProperty)
 {
     QV4::ExecutionEngine *v4 = m->engine();
     NodeList *r = m->as<NodeList>();
@@ -926,7 +926,7 @@ Value NodeList::get(Managed *m, String *name, bool *hasProperty)
     name->makeIdentifier();
 
     if (name->isEqualTo(v4->id_length))
-        return Value::fromInt32(r->d->children.count());
+        return Value::fromInt32(r->d->children.count()).asReturnedValue();
     return Object::get(m, name, hasProperty);
 }
 
@@ -1467,24 +1467,24 @@ void QQmlXMLHttpRequest::dispatchCallback(const Value &me)
         if (!o)
             ctx->throwError(QStringLiteral("QQmlXMLHttpRequest: internal error: empty ThisObject"));
 
-        Object *thisObj = o->get(v4->newString(QStringLiteral("ThisObject"))).asObject();
+        Scoped<Object> thisObj(scope, o->get(v4->newString(QStringLiteral("ThisObject"))));
         if (!thisObj)
             ctx->throwError(QStringLiteral("QQmlXMLHttpRequest: internal error: empty ThisObject"));
 
-        FunctionObject *callback = thisObj->get(v4->newString(QStringLiteral("onreadystatechange"))).asFunctionObject();
+        Scoped<FunctionObject> callback(scope, thisObj->get(v4->newString(QStringLiteral("onreadystatechange"))));
         if (!callback) {
             // not an error, but no onreadystatechange function to call.
             return;
         }
 
-        Value activationObject = o->get(v4->newString(QStringLiteral("ActivationObject")));
-        if (!activationObject.asObject())
+        Scoped<Object> activationObject(scope, o->get(v4->newString(QStringLiteral("ActivationObject"))));
+        if (!activationObject)
             v4->current->throwError(QStringLiteral("QQmlXMLHttpRequest: internal error: empty ActivationObject"));
 
-        QQmlContextData *callingContext = QmlContextWrapper::getContext(activationObject);
+        QQmlContextData *callingContext = QmlContextWrapper::getContext(activationObject.asValue());
         if (callingContext) {
             QV4::ScopedCallData callData(scope, 0);
-            callData->thisObject = activationObject;
+            callData->thisObject = activationObject.asValue();
             callback->call(callData);
         }
 
diff --git a/src/qml/types/qqmldelegatemodel.cpp b/src/qml/types/qqmldelegatemodel.cpp
index 0744b18197..bb75a47eef 100644
--- a/src/qml/types/qqmldelegatemodel.cpp
+++ b/src/qml/types/qqmldelegatemodel.cpp
@@ -3168,7 +3168,7 @@ public:
         return QV4::Value::fromObject(object);
     }
 
-    static QV4::Value get(QV4::Managed *m, QV4::String *name, bool *hasProperty)
+    static QV4::ReturnedValue get(QV4::Managed *m, QV4::String *name, bool *hasProperty)
     {
         QQmlDelegateModelGroupChangeArray *array = m->as<QQmlDelegateModelGroupChangeArray>();
         if (!array)
@@ -3177,7 +3177,7 @@ public:
         if (name == m->engine()->id_length) {
             if (hasProperty)
                 *hasProperty = true;
-            return QV4::Value::fromInt32(array->count());
+            return QV4::Value::fromInt32(array->count()).asReturnedValue();
         }
 
         return Object::get(m, name, hasProperty);
diff --git a/src/quick/items/context2d/qquickcontext2d.cpp b/src/quick/items/context2d/qquickcontext2d.cpp
index f17b3d45e6..81f5505245 100644
--- a/src/quick/items/context2d/qquickcontext2d.cpp
+++ b/src/quick/items/context2d/qquickcontext2d.cpp
@@ -68,6 +68,7 @@
 #include <private/qv4value_p.h>
 #include <private/qv4functionobject_p.h>
 #include <private/qv4objectproto_p.h>
+#include <private/qv4scopedvalue_p.h>
 
 #if defined(Q_OS_QNX) || defined(Q_OS_ANDROID)
 #include <ctype.h>
@@ -1673,6 +1674,7 @@ QV4::Value QQuickJSContext2DPrototype::method_createPattern(QV4::SimpleCallConte
 
     QV8Engine *engine = ctx->engine->v8Engine;
     QV4::ExecutionEngine *v4 = QV8Engine::getV4(engine);
+    QV4::Scope scope(v4);
 
     if (ctx->argumentCount == 2) {
         QQuickContext2DStyle *pattern = new (v4->memoryManager) QQuickContext2DStyle(v4);
@@ -1689,8 +1691,8 @@ QV4::Value QQuickJSContext2DPrototype::method_createPattern(QV4::SimpleCallConte
             QImage patternTexture;
 
             if (QV4::Object *o = ctx->arguments[0].asObject()) {
-                QQuickJSContext2DPixelData *pixelData = o->get(ctx->engine->newString(QStringLiteral("data"))).as<QQuickJSContext2DPixelData>();
-                if (pixelData) {
+                QV4::Scoped<QQuickJSContext2DPixelData> pixelData(scope, o->get(ctx->engine->newString(QStringLiteral("data"))));
+                if (!!pixelData) {
                     patternTexture = pixelData->image;
                 }
             } else {
diff --git a/src/quick/util/qquickglobal.cpp b/src/quick/util/qquickglobal.cpp
index 117b89e88b..1af04505b3 100644
--- a/src/quick/util/qquickglobal.cpp
+++ b/src/quick/util/qquickglobal.cpp
@@ -326,17 +326,17 @@ public:
 
         QV4::ExecutionEngine *v4 = obj->engine();
 
-        QV4::Value vbold = obj->get(v4->newString(QStringLiteral("bold")));
-        QV4::Value vcap = obj->get(v4->newString(QStringLiteral("capitalization")));
-        QV4::Value vfam = obj->get(v4->newString(QStringLiteral("family")));
-        QV4::Value vital = obj->get(v4->newString(QStringLiteral("italic")));
-        QV4::Value vlspac = obj->get(v4->newString(QStringLiteral("letterSpacing")));
-        QV4::Value vpixsz = obj->get(v4->newString(QStringLiteral("pixelSize")));
-        QV4::Value vpntsz = obj->get(v4->newString(QStringLiteral("pointSize")));
-        QV4::Value vstrk = obj->get(v4->newString(QStringLiteral("strikeout")));
-        QV4::Value vundl = obj->get(v4->newString(QStringLiteral("underline")));
-        QV4::Value vweight = obj->get(v4->newString(QStringLiteral("weight")));
-        QV4::Value vwspac = obj->get(v4->newString(QStringLiteral("wordSpacing")));
+        QV4::Value vbold = QV4::Value::fromReturnedValue(obj->get(v4->newString(QStringLiteral("bold"))));
+        QV4::Value vcap = QV4::Value::fromReturnedValue(obj->get(v4->newString(QStringLiteral("capitalization"))));
+        QV4::Value vfam = QV4::Value::fromReturnedValue(obj->get(v4->newString(QStringLiteral("family"))));
+        QV4::Value vital = QV4::Value::fromReturnedValue(obj->get(v4->newString(QStringLiteral("italic"))));
+        QV4::Value vlspac = QV4::Value::fromReturnedValue(obj->get(v4->newString(QStringLiteral("letterSpacing"))));
+        QV4::Value vpixsz = QV4::Value::fromReturnedValue(obj->get(v4->newString(QStringLiteral("pixelSize"))));
+        QV4::Value vpntsz = QV4::Value::fromReturnedValue(obj->get(v4->newString(QStringLiteral("pointSize"))));
+        QV4::Value vstrk = QV4::Value::fromReturnedValue(obj->get(v4->newString(QStringLiteral("strikeout"))));
+        QV4::Value vundl = QV4::Value::fromReturnedValue(obj->get(v4->newString(QStringLiteral("underline"))));
+        QV4::Value vweight = QV4::Value::fromReturnedValue(obj->get(v4->newString(QStringLiteral("weight"))));
+        QV4::Value vwspac = QV4::Value::fromReturnedValue(obj->get(v4->newString(QStringLiteral("wordSpacing"))));
 
         // pull out the values, set ok to true if at least one valid field is given.
         if (vbold.isBoolean()) {
diff --git a/tools/v4/main.cpp b/tools/v4/main.cpp
index 2ae21914c4..b612a5d1ab 100644
--- a/tools/v4/main.cpp
+++ b/tools/v4/main.cpp
@@ -121,7 +121,7 @@ static void showException(QV4::ExecutionContext *ctx, const QV4::Exception &exce
     if (!e) {
         std::cerr << "Uncaught exception: " << qPrintable(exception.value().toString(ctx)->toQString()) << std::endl;
     } else {
-        std::cerr << "Uncaught exception: " << qPrintable(e->get(ctx->engine->newString(QStringLiteral("message")), 0).toString(ctx)->toQString()) << std::endl;
+        std::cerr << "Uncaught exception: " << qPrintable(QV4::Value::fromReturnedValue(e->get(ctx->engine->newString(QStringLiteral("message")), 0)).toString(ctx)->toQString()) << std::endl;
     }
 
     foreach (const QV4::ExecutionEngine::StackFrame &frame, exception.stackTrace()) {