Use StringRef for most methods in Object

Change-Id: I8e2dad0e9e34c5a549952bc0765cd57f6aa8aadf
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

16 files changed, 103 insertions, 70 deletions

diff --git a/src/qml/jsapi/qjsvalue.cpp b/src/qml/jsapi/qjsvalue.cpp
index 6b3d15df59..87c45e4779 100644
--- a/src/qml/jsapi/qjsvalue.cpp
+++ b/src/qml/jsapi/qjsvalue.cpp
@@ -974,12 +974,16 @@ bool QJSValue::deleteProperty(const QString &name)
 */
 bool QJSValue::hasProperty(const QString &name) const
 {
-    Object *o = d->value.asObject();
+    ExecutionEngine *engine = d->engine;
+    if (!engine)
+        return false;
+
+    Scope scope(engine);
+    ScopedObject o(scope, d->value);
     if (!o)
         return false;
 
-    ExecutionEngine *engine = d->engine;
-    String *s = engine->newIdentifier(name);
+    ScopedString s(scope, engine->newIdentifier(name));
     return o->__hasProperty__(s);
 }
 
@@ -991,12 +995,16 @@ bool QJSValue::hasProperty(const QString &name) const
 */
 bool QJSValue::hasOwnProperty(const QString &name) const
 {
-    Object *o = d->value.asObject();
+    ExecutionEngine *engine = d->engine;
+    if (!engine)
+        return false;
+
+    Scope scope(engine);
+    ScopedObject o(scope, d->value);
     if (!o)
         return false;
 
-    ExecutionEngine *engine = d->engine;
-    String *s = engine->newIdentifier(name);
+    ScopedString s(scope, engine->newIdentifier(name));
     return o->__getOwnProperty__(s);
 }
 
diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index 01cb2dd780..449ec21b05 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -174,6 +174,8 @@ CallContext *ExecutionContext::newQmlContext(FunctionObject *f, Object *qml)
 
 void ExecutionContext::createMutableBinding(String *name, bool deletable)
 {
+    Scope scope(this);
+    ScopedString n(scope, name);
 
     // find the right context to create the binding on
     Object *activation = engine->globalObject;
@@ -189,12 +191,12 @@ void ExecutionContext::createMutableBinding(String *name, bool deletable)
         ctx = ctx->outer;
     }
 
-    if (activation->__hasProperty__(name))
+    if (activation->__hasProperty__(n))
         return;
     Property desc = Property::fromValue(Value::undefinedValue());
     PropertyAttributes attrs(Attr_Data);
     attrs.setConfigurable(deletable);
-    activation->__defineOwnProperty__(this, name, desc, attrs);
+    activation->__defineOwnProperty__(this, n, desc, attrs);
 }
 
 String * const *ExecutionContext::formals() const
@@ -286,12 +288,14 @@ void CallContext::initQmlContext(ExecutionContext *parentContext, Object *qml, F
 
 bool ExecutionContext::deleteProperty(String *name)
 {
+    Scope scope(this);
+    ScopedString n(scope, name);
     bool hasWith = false;
     for (ExecutionContext *ctx = this; ctx; ctx = ctx->outer) {
         if (ctx->type == Type_WithContext) {
             hasWith = true;
             WithContext *w = static_cast<WithContext *>(ctx);
-            if (w->withObject->__hasProperty__(name))
+            if (w->withObject->__hasProperty__(n))
                 return w->withObject->deleteProperty(name);
         } else if (ctx->type == Type_CatchContext) {
             CatchContext *c = static_cast<CatchContext *>(ctx);
@@ -308,11 +312,11 @@ bool ExecutionContext::deleteProperty(String *name)
                     if (f->formalParameterList[i]->isEqualTo(name))
                         return false;
             }
-            if (c->activation && c->activation->__hasProperty__(name))
+            if (c->activation && c->activation->__hasProperty__(n))
                 return c->activation->deleteProperty(name);
         } else if (ctx->type == Type_GlobalContext) {
             GlobalContext *g = static_cast<GlobalContext *>(ctx);
-            if (g->global->__hasProperty__(name))
+            if (g->global->__hasProperty__(n))
                 return g->global->deleteProperty(name);
         }
     }
@@ -366,10 +370,11 @@ void ExecutionContext::mark()
 void ExecutionContext::setProperty(String *name, const Value& value)
 {
     Scope scope(this);
+    ScopedString n(scope, name);
     for (ExecutionContext *ctx = this; ctx; ctx = ctx->outer) {
         if (ctx->type == Type_WithContext) {
             Object *w = static_cast<WithContext *>(ctx)->withObject;
-            if (w->__hasProperty__(name)) {
+            if (w->__hasProperty__(n)) {
                 w->put(name, value);
                 return;
             }
@@ -395,7 +400,7 @@ void ExecutionContext::setProperty(String *name, const Value& value)
                 activation = static_cast<GlobalContext *>(ctx)->global;
             }
 
-            if (activation && (ctx->type == Type_QmlContext || activation->__hasProperty__(name))) {
+            if (activation && (ctx->type == Type_QmlContext || activation->__hasProperty__(n))) {
                 activation->put(name, value);
                 return;
             }
diff --git a/src/qml/jsruntime/qv4debugging.cpp b/src/qml/jsruntime/qv4debugging.cpp
index 34b72e95fb..b4da4bba87 100644
--- a/src/qml/jsruntime/qv4debugging.cpp
+++ b/src/qml/jsruntime/qv4debugging.cpp
@@ -273,11 +273,11 @@ static void realDumpValue(QV4::Value v, QV4::ExecutionContext *ctx, std::string
 
     cout << prefix << "properties:" << endl;
     ForEachIteratorObject it(ctx, o);
-    QV4::ScopedValue name(scope);
+    ScopedValue name(scope);
     for (name = it.nextPropertyName(); !name->isNull(); name = it.nextPropertyName()) {
         cout << prefix << "\t\"" << qPrintable(name->stringValue()->toQString()) << "\"" << endl;
         PropertyAttributes attrs;
-        Property *d = o->__getOwnProperty__(name->stringValue(), &attrs);
+        Property *d = o->__getOwnProperty__(ScopedString(scope, name), &attrs);
         Value pval = Value::fromReturnedValue(o->getValue(d, attrs));
         cout << prefix << "\tvalue:" << endl;
         realDumpValue(pval, ctx, prefix + "\t");
diff --git a/src/qml/jsruntime/qv4identifiertable.cpp b/src/qml/jsruntime/qv4identifiertable.cpp
index 618696a124..6553e78b22 100644
--- a/src/qml/jsruntime/qv4identifiertable.cpp
+++ b/src/qml/jsruntime/qv4identifiertable.cpp
@@ -135,7 +135,7 @@ String *IdentifierTable::insertString(const QString &s)
 }
 
 
-Identifier *IdentifierTable::identifierImpl(String *str)
+Identifier *IdentifierTable::identifierImpl(const String *str)
 {
     if (str->identifier)
         return str->identifier;
@@ -153,7 +153,7 @@ Identifier *IdentifierTable::identifierImpl(String *str)
         idx %= alloc;
     }
 
-    addEntry(str);
+    addEntry(const_cast<QV4::String *>(str));
     return str->identifier;
 }
 
diff --git a/src/qml/jsruntime/qv4identifiertable_p.h b/src/qml/jsruntime/qv4identifiertable_p.h
index 6450a874d2..a02d90e7e2 100644
--- a/src/qml/jsruntime/qv4identifiertable_p.h
+++ b/src/qml/jsruntime/qv4identifiertable_p.h
@@ -68,7 +68,7 @@ public:
 
     String *insertString(const QString &s);
 
-    Identifier *identifier(String *str) {
+    Identifier *identifier(const String *str) {
         if (str->identifier)
             return str->identifier;
         return identifierImpl(str);
@@ -77,7 +77,7 @@ public:
     Identifier *identifier(const QString &s);
     Identifier *identifier(const char *s, int len);
 
-    Identifier *identifierImpl(String *str);
+    Identifier *identifierImpl(const String *str);
 
     void mark() {
         for (int i = 0; i < alloc; ++i)
diff --git a/src/qml/jsruntime/qv4internalclass.cpp b/src/qml/jsruntime/qv4internalclass.cpp
index 16038b0b68..4f6adc2c88 100644
--- a/src/qml/jsruntime/qv4internalclass.cpp
+++ b/src/qml/jsruntime/qv4internalclass.cpp
@@ -255,7 +255,7 @@ void InternalClass::removeMember(Object *object, Identifier *id)
     transitions.insert(t, object->internalClass);
 }
 
-uint InternalClass::find(String *string)
+uint InternalClass::find(const String *string)
 {
     engine->identifierTable->identifier(string);
     const Identifier *id = string->identifier;
diff --git a/src/qml/jsruntime/qv4internalclass_p.h b/src/qml/jsruntime/qv4internalclass_p.h
index 1fba947a37..ecb5c0bfab 100644
--- a/src/qml/jsruntime/qv4internalclass_p.h
+++ b/src/qml/jsruntime/qv4internalclass_p.h
@@ -140,7 +140,7 @@ struct InternalClass {
     InternalClass *addMember(String *string, PropertyAttributes data, uint *index = 0);
     InternalClass *changeMember(String *string, PropertyAttributes data, uint *index = 0);
     void removeMember(Object *object, Identifier *id);
-    uint find(String *s);
+    uint find(const String *s);
 
     InternalClass *sealed();
     InternalClass *frozen();
diff --git a/src/qml/jsruntime/qv4object.cpp b/src/qml/jsruntime/qv4object.cpp
index 3acf4bf9ab..68469f1f2d 100644
--- a/src/qml/jsruntime/qv4object.cpp
+++ b/src/qml/jsruntime/qv4object.cpp
@@ -318,7 +318,7 @@ Property *Object::insertMember(const StringRef s, PropertyAttributes attributes)
 }
 
 // Section 8.12.1
-Property *Object::__getOwnProperty__(String *name, PropertyAttributes *attrs)
+Property *Object::__getOwnProperty__(const StringRef name, PropertyAttributes *attrs)
 {
     uint idx = name->asArrayIndex();
     if (idx != UINT_MAX)
@@ -363,7 +363,7 @@ Property *Object::__getOwnProperty__(uint index, PropertyAttributes *attrs)
 }
 
 // Section 8.12.2
-Property *Object::__getPropertyDescriptor__(String *name, PropertyAttributes *attrs) const
+Property *Object::__getPropertyDescriptor__(const StringRef name, PropertyAttributes *attrs) const
 {
     uint idx = name->asArrayIndex();
     if (idx != UINT_MAX)
@@ -372,7 +372,7 @@ Property *Object::__getPropertyDescriptor__(String *name, PropertyAttributes *at
 
     const Object *o = this;
     while (o) {
-        uint idx = o->internalClass->find(name);
+        uint idx = o->internalClass->find(name.getPointer());
         if (idx < UINT_MAX) {
             if (attrs)
                 *attrs = o->internalClass->propertyData[idx];
@@ -414,14 +414,14 @@ Property *Object::__getPropertyDescriptor__(uint index, PropertyAttributes *attr
     return 0;
 }
 
-bool Object::__hasProperty__(String *name) const
+bool Object::__hasProperty__(const StringRef name) const
 {
     if (__getPropertyDescriptor__(name))
         return true;
 
     const Object *o = this;
     while (o) {
-        if (!o->query(name).isEmpty())
+        if (!o->query(name.getPointer()).isEmpty())
             return true;
         o = o->prototype();
     }
@@ -456,7 +456,9 @@ ReturnedValue Object::getIndexed(Managed *m, uint index, bool *hasProperty)
 
 void Object::put(Managed *m, String *name, const Value &value)
 {
-    static_cast<Object *>(m)->internalPut(name, value);
+    Scope scope(m->engine());
+    ScopedString s(scope, name);
+    static_cast<Object *>(m)->internalPut(s, value);
 }
 
 void Object::putIndexed(Managed *m, uint index, const Value &value)
@@ -704,7 +706,7 @@ ReturnedValue Object::internalGetIndexed(uint index, bool *hasProperty)
 
 
 // Section 8.12.5
-void Object::internalPut(String *name, const Value &value)
+void Object::internalPut(const StringRef name, const Value &value)
 {
     uint idx = name->asArrayIndex();
     if (idx != UINT_MAX)
@@ -712,7 +714,7 @@ void Object::internalPut(String *name, const Value &value)
 
     name->makeIdentifier();
 
-    uint member = internalClass->find(name);
+    uint member = internalClass->find(name.getPointer());
     Property *pd = 0;
     PropertyAttributes attrs;
     if (member < UINT_MAX) {
@@ -772,9 +774,7 @@ void Object::internalPut(String *name, const Value &value)
     }
 
     {
-        Scope scope(engine());
-        ScopedString s(scope, name);
-        Property *p = insertMember(s, Attr_Data);
+        Property *p = insertMember(name, Attr_Data);
         p->value = value;
         return;
     }
@@ -910,7 +910,7 @@ bool Object::internalDeleteIndexedProperty(uint index)
 }
 
 // Section 8.12.9
-bool Object::__defineOwnProperty__(ExecutionContext *ctx, String *name, const Property &p, PropertyAttributes attrs)
+bool Object::__defineOwnProperty__(ExecutionContext *ctx, const StringRef name, const Property &p, PropertyAttributes attrs)
 {
     uint idx = name->asArrayIndex();
     if (idx != UINT_MAX)
@@ -948,7 +948,7 @@ bool Object::__defineOwnProperty__(ExecutionContext *ctx, String *name, const Pr
 
     // Clause 1
     {
-        uint member = internalClass->find(name);
+        uint member = internalClass->find(name.getPointer());
         current = (member < UINT_MAX) ? memberData + member : 0;
         cattrs = internalClass->propertyData.data() + member;
     }
@@ -958,9 +958,7 @@ bool Object::__defineOwnProperty__(ExecutionContext *ctx, String *name, const Pr
         if (!extensible)
             goto reject;
         // clause 4
-        Scope scope(engine());
-        ScopedString s(scope, name);
-        Property *pd = insertMember(s, attrs);
+        Property *pd = insertMember(name, attrs);
         *pd = p;
         pd->fullyPopulated(&attrs);
         return true;
@@ -1004,21 +1002,21 @@ bool Object::__defineOwnProperty__(ExecutionContext *ctx, uint index, const Prop
         return true;
     }
 
-    return __defineOwnProperty__(ctx, current, 0 /*member*/, p, attrs);
+    return __defineOwnProperty__(ctx, current, StringRef::null(), p, attrs);
 reject:
   if (ctx->strictMode)
       ctx->throwTypeError();
   return false;
 }
 
-bool Object::__defineOwnProperty__(ExecutionContext *ctx, Property *current, String *member, const Property &p, PropertyAttributes attrs)
+bool Object::__defineOwnProperty__(ExecutionContext *ctx, Property *current, const StringRef member, const Property &p, PropertyAttributes attrs)
 {
     // clause 5
     if (attrs.isEmpty())
         return true;
 
     PropertyAttributes cattrs = Attr_Data;
-    if (member)
+    if (!member.isNull())
         cattrs = internalClass->propertyData[current - memberData];
     else if (arrayAttributes)
         cattrs = arrayAttributes[current - arrayData];
@@ -1074,8 +1072,8 @@ bool Object::__defineOwnProperty__(ExecutionContext *ctx, Property *current, Str
   accept:
 
     current->merge(cattrs, p, attrs);
-    if (member) {
-        internalClass = internalClass->changeMember(member, cattrs);
+    if (!member.isNull()) {
+        internalClass = internalClass->changeMember(member.getPointer(), cattrs);
     } else {
         if (cattrs != Attr_Data)
             ensureArrayAttributes();
@@ -1094,7 +1092,9 @@ bool Object::__defineOwnProperty__(ExecutionContext *ctx, Property *current, Str
 
 bool Object::__defineOwnProperty__(ExecutionContext *ctx, const QString &name, const Property &p, PropertyAttributes attrs)
 {
-    return __defineOwnProperty__(ctx, ctx->engine->newString(name), p, attrs);
+    Scope scope(ctx);
+    ScopedString s(scope, ctx->engine->newString(name));
+    return __defineOwnProperty__(ctx, s, p, attrs);
 }
 
 
diff --git a/src/qml/jsruntime/qv4object_p.h b/src/qml/jsruntime/qv4object_p.h
index 0ca64f71fe..17e0b6dcf5 100644
--- a/src/qml/jsruntime/qv4object_p.h
+++ b/src/qml/jsruntime/qv4object_p.h
@@ -131,17 +131,17 @@ struct Q_QML_EXPORT Object: Managed {
     Object *prototype() const { return internalClass->prototype; }
     bool setPrototype(Object *proto);
 
-    Property *__getOwnProperty__(String *name, PropertyAttributes *attrs = 0);
+    Property *__getOwnProperty__(const StringRef name, PropertyAttributes *attrs = 0);
     Property *__getOwnProperty__(uint index, PropertyAttributes *attrs = 0);
 
-    Property *__getPropertyDescriptor__(String *name, PropertyAttributes *attrs = 0) const;
+    Property *__getPropertyDescriptor__(const StringRef name, PropertyAttributes *attrs = 0) const;
     Property *__getPropertyDescriptor__(uint index, PropertyAttributes *attrs = 0) const;
 
-    bool __hasProperty__(String *name) const;
+    bool __hasProperty__(const StringRef name) const;
     bool __hasProperty__(uint index) const;
 
-    bool __defineOwnProperty__(ExecutionContext *ctx, Property *current, String *member, const Property &p, PropertyAttributes attrs);
-    bool __defineOwnProperty__(ExecutionContext *ctx, String *name, const Property &p, PropertyAttributes attrs);
+    bool __defineOwnProperty__(ExecutionContext *ctx, Property *current, const StringRef member, const Property &p, PropertyAttributes attrs);
+    bool __defineOwnProperty__(ExecutionContext *ctx, const StringRef name, const Property &p, PropertyAttributes attrs);
     bool __defineOwnProperty__(ExecutionContext *ctx, uint index, const Property &p, PropertyAttributes attrs);
     bool __defineOwnProperty__(ExecutionContext *ctx, const QString &name, const Property &p, PropertyAttributes attrs);
 
@@ -325,7 +325,7 @@ protected:
 private:
     ReturnedValue internalGet(String *name, bool *hasProperty);
     ReturnedValue internalGetIndexed(uint index, bool *hasProperty);
-    void internalPut(String *name, const Value &value);
+    void internalPut(const StringRef name, const Value &value);
     void internalPutIndexed(uint index, const Value &value);
     bool internalDeleteProperty(String *name);
     bool internalDeleteIndexedProperty(uint index);
diff --git a/src/qml/jsruntime/qv4objectiterator.cpp b/src/qml/jsruntime/qv4objectiterator.cpp
index f03c2d6b86..a9c9e817f7 100644
--- a/src/qml/jsruntime/qv4objectiterator.cpp
+++ b/src/qml/jsruntime/qv4objectiterator.cpp
@@ -70,7 +70,9 @@ Property *ObjectIterator::next(String **name, uint *index, PropertyAttributes *a
             if (current != object) {
                 Property *pp;
                 if (*name) {
-                    pp = object->__getPropertyDescriptor__(*name);
+                    Scope scope(object->engine());
+                    ScopedString n(scope, *name);
+                    pp = object->__getPropertyDescriptor__(n);
                 } else {
                     assert (*index != UINT_MAX);
                     pp = object->__getPropertyDescriptor__(*index);
diff --git a/src/qml/jsruntime/qv4objectproto.cpp b/src/qml/jsruntime/qv4objectproto.cpp
index 67aeebf0a8..9cbf14990b 100644
--- a/src/qml/jsruntime/qv4objectproto.cpp
+++ b/src/qml/jsruntime/qv4objectproto.cpp
@@ -158,7 +158,7 @@ ReturnedValue ObjectPrototype::method_getOwnPropertyDescriptor(SimpleCallContext
     ScopedValue v(scope, ctx->argument(1));
     Scoped<String> name(scope, v->toString(ctx));
     PropertyAttributes attrs;
-    Property *desc = O->__getOwnProperty__(name.getPointer(), &attrs);
+    Property *desc = O->__getOwnProperty__(name, &attrs);
     return fromPropertyDescriptor(ctx, desc, attrs);
 }
 
@@ -204,7 +204,7 @@ ReturnedValue ObjectPrototype::method_defineProperty(SimpleCallContext *ctx)
     PropertyAttributes attrs;
     toPropertyDescriptor(ctx, attributes, &pd, &attrs);
 
-    if (!O->__defineOwnProperty__(ctx, name.getPointer(), pd, attrs))
+    if (!O->__defineOwnProperty__(ctx, name, pd, attrs))
         ctx->throwTypeError();
 
     return O.asReturnedValue();
@@ -222,9 +222,11 @@ ReturnedValue ObjectPrototype::method_defineProperties(SimpleCallContext *ctx)
     ObjectIterator it(o.getPointer(), ObjectIterator::EnumerableOnly);
     while (1) {
         uint index;
-        String *name;
+        ScopedString name(scope);
         PropertyAttributes attrs;
-        Property *pd = it.next(&name, &index, &attrs);
+        String *tmp = 0;
+        Property *pd = it.next(&tmp, &index, &attrs);
+        name = tmp;
         if (!pd)
             break;
         Property n;
@@ -416,7 +418,7 @@ ReturnedValue ObjectPrototype::method_hasOwnProperty(SimpleCallContext *ctx)
     Scope scope(ctx);
     Scoped<String> P(scope, ctx->argument(0), Scoped<String>::Convert);
     Scoped<Object> O(scope, ctx->thisObject, Scoped<Object>::Convert);
-    bool r = O->__getOwnProperty__(P.getPointer()) != 0;
+    bool r = O->__getOwnProperty__(P) != 0;
     if (!r)
         r = !O->query(P.getPointer()).isEmpty();
     return Encode(r);
@@ -446,7 +448,7 @@ ReturnedValue ObjectPrototype::method_propertyIsEnumerable(SimpleCallContext *ct
 
     Scoped<Object> o(scope, ctx->thisObject, Scoped<Object>::Convert);
     PropertyAttributes attrs;
-    o->__getOwnProperty__(p.getPointer(), &attrs);
+    o->__getOwnProperty__(p, &attrs);
     return Encode(attrs.isEnumerable());
 }
 
@@ -470,7 +472,7 @@ ReturnedValue ObjectPrototype::method_defineGetter(SimpleCallContext *ctx)
     }
 
     Property pd = Property::fromAccessor(f.getPointer(), 0);
-    o->__defineOwnProperty__(ctx, prop.getPointer(), pd, Attr_Accessor);
+    o->__defineOwnProperty__(ctx, prop, pd, Attr_Accessor);
     return Encode::undefined();
 }
 
@@ -494,7 +496,7 @@ ReturnedValue ObjectPrototype::method_defineSetter(SimpleCallContext *ctx)
     }
 
     Property pd = Property::fromAccessor(0, f.getPointer());
-    o->__defineOwnProperty__(ctx, prop.getPointer(), pd, Attr_Accessor);
+    o->__defineOwnProperty__(ctx, prop, pd, Attr_Accessor);
     return Encode::undefined();
 }
 
@@ -607,23 +609,30 @@ ReturnedValue ObjectPrototype::fromPropertyDescriptor(ExecutionContext *ctx, con
     Scope scope(engine);
 //    Let obj be the result of creating a new object as if by the expression new Object() where Object is the standard built-in constructor with that name.
     Scoped<Object> o(scope, engine->newObject());
+    ScopedString s(scope);
 
     Property pd;
     if (attrs.isData()) {
         pd.value = desc->value;
-        o->__defineOwnProperty__(ctx, engine->newString(QStringLiteral("value")), pd, Attr_Data);
+        s = engine->newString(QStringLiteral("value"));
+        o->__defineOwnProperty__(ctx, s, pd, Attr_Data);
         pd.value = Value::fromBoolean(attrs.isWritable());
-        o->__defineOwnProperty__(ctx, engine->newString(QStringLiteral("writable")), pd, Attr_Data);
+        s = engine->newString(QStringLiteral("writable"));
+        o->__defineOwnProperty__(ctx, s, pd, Attr_Data);
     } else {
         pd.value = desc->getter() ? Value::fromObject(desc->getter()) : Value::undefinedValue();
-        o->__defineOwnProperty__(ctx, engine->newString(QStringLiteral("get")), pd, Attr_Data);
+        s = engine->newString(QStringLiteral("get"));
+        o->__defineOwnProperty__(ctx, s, pd, Attr_Data);
         pd.value = desc->setter() ? Value::fromObject(desc->setter()) : Value::undefinedValue();
-        o->__defineOwnProperty__(ctx, engine->newString(QStringLiteral("set")), pd, Attr_Data);
+        s = engine->newString(QStringLiteral("set"));
+        o->__defineOwnProperty__(ctx, s, pd, Attr_Data);
     }
     pd.value = Value::fromBoolean(attrs.isEnumerable());
-    o->__defineOwnProperty__(ctx, engine->newString(QStringLiteral("enumerable")), pd, Attr_Data);
+    s = engine->newString(QStringLiteral("enumerable"));
+    o->__defineOwnProperty__(ctx, s, pd, Attr_Data);
     pd.value = Value::fromBoolean(attrs.isConfigurable());
-    o->__defineOwnProperty__(ctx, engine->newString(QStringLiteral("configurable")), pd, Attr_Data);
+    s = engine->newString(QStringLiteral("configurable"));
+    o->__defineOwnProperty__(ctx, s, pd, Attr_Data);
 
     return o.asReturnedValue();
 }
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index c01f172eb3..644db82823 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -304,7 +304,8 @@ QV4::ReturnedValue __qmljs_in(ExecutionContext *ctx, const ValueRef left, const
 {
     if (!right->isObject())
         ctx->throwTypeError();
-    String *s = left->toString(ctx);
+    Scope scope(ctx);
+    ScopedString s(scope, left->toString(ctx));
     bool r = right->objectValue()->__hasProperty__(s);
     return Value::fromBoolean(r).asReturnedValue();
 }
diff --git a/src/qml/jsruntime/qv4scopedvalue_p.h b/src/qml/jsruntime/qv4scopedvalue_p.h
index 58bad216fa..5ec0497f15 100644
--- a/src/qml/jsruntime/qv4scopedvalue_p.h
+++ b/src/qml/jsruntime/qv4scopedvalue_p.h
@@ -450,7 +450,11 @@ struct Referenced {
     }
     ReturnedValue asReturnedValue() const { return ptr->val; }
 
+    static Referenced null() { return Referenced(Null); }
+    bool isNull() const { return !ptr; }
 private:
+    enum _Null { Null };
+    Referenced(_Null) { ptr = 0; }
     Value *ptr;
 };
 
diff --git a/src/qml/jsruntime/qv4string.cpp b/src/qml/jsruntime/qv4string.cpp
index bd1f14b680..806c37b283 100644
--- a/src/qml/jsruntime/qv4string.cpp
+++ b/src/qml/jsruntime/qv4string.cpp
@@ -131,6 +131,9 @@ void String::destroy(Managed *that)
 
 ReturnedValue String::get(Managed *m, String *name, bool *hasProperty)
 {
+    Scope scope(m->engine());
+    ScopedString n(scope, name);
+
     String *that = static_cast<String *>(m);
     ExecutionEngine *v4 = m->engine();
     if (name == v4->id_length) {
@@ -139,7 +142,7 @@ ReturnedValue String::get(Managed *m, String *name, bool *hasProperty)
         return Value::fromInt32(that->_text.length()).asReturnedValue();
     }
     PropertyAttributes attrs;
-    Property *pd = v4->stringClass->prototype->__getPropertyDescriptor__(name, &attrs);
+    Property *pd = v4->stringClass->prototype->__getPropertyDescriptor__(n, &attrs);
     if (!pd || attrs.isGeneric()) {
         if (hasProperty)
             *hasProperty = false;
@@ -256,7 +259,7 @@ uint String::toUInt(bool *ok) const
     return UINT_MAX;
 }
 
-void String::makeIdentifierImpl()
+void String::makeIdentifierImpl() const
 {
     engine()->identifierTable->identifier(this);
 }
diff --git a/src/qml/jsruntime/qv4string_p.h b/src/qml/jsruntime/qv4string_p.h
index 7ad428a502..840e940802 100644
--- a/src/qml/jsruntime/qv4string_p.h
+++ b/src/qml/jsruntime/qv4string_p.h
@@ -101,13 +101,13 @@ struct Q_QML_EXPORT String : public Managed {
     }
     uint toUInt(bool *ok) const;
 
-    void makeIdentifier() {
+    void makeIdentifier() const {
         if (identifier)
             return;
         makeIdentifierImpl();
     }
 
-    void makeIdentifierImpl();
+    void makeIdentifierImpl() const;
 
     void createHashValue() const;
     static uint createHashValue(const QChar *ch, int length);
diff --git a/src/qml/qml/qqmlcontextwrapper.cpp b/src/qml/qml/qqmlcontextwrapper.cpp
index de317a2dcb..234700c675 100644
--- a/src/qml/qml/qqmlcontextwrapper.cpp
+++ b/src/qml/qml/qqmlcontextwrapper.cpp
@@ -293,7 +293,8 @@ void QmlContextWrapper::put(Managed *m, String *name, const Value &value)
     }
 
     PropertyAttributes attrs;
-    Property *pd  = wrapper->__getOwnProperty__(name, &attrs);
+    ScopedString n(scope, name);
+    Property *pd  = wrapper->__getOwnProperty__(n, &attrs);
     if (pd) {
         wrapper->putValue(pd, attrs, value);
         return;