Fix tst_qjsvalue::castToPointer test failure

In order for casting the variant's data() to work,
we need to get at the actual QVariant wrapped in
the JS object; copying the variant caused a stale
pointer to be returned.

Task-number: QTBUG-21000
Change-Id: I1a32a70d5a043c94dbbd07ef2c8048e7df7fc7bf
Reviewed-on: http://codereview.qt.nokia.com/3309
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Simon Hausmann <simon.hausmann@nokia.com>

5 files changed, 14 insertions, 11 deletions

diff --git a/src/declarative/qml/v8/qv8engine.cpp b/src/declarative/qml/v8/qv8engine.cpp
index 84892d785c..4f5caa13f4 100644
--- a/src/declarative/qml/v8/qv8engine.cpp
+++ b/src/declarative/qml/v8/qv8engine.cpp
@@ -2107,14 +2107,14 @@ bool QV8Engine::metaTypeFromJS(v8::Handle<v8::Value> value, int type, void *data
     }
 #endif
 
-    // Try to use magic.
+    // Try to use magic; for compatibility with qscriptvalue_cast.
 
     QByteArray name = QMetaType::typeName(type);
     if (convertToNativeQObject(value, name, reinterpret_cast<void* *>(data)))
         return true;
     if (isVariant(value) && name.endsWith('*')) {
         int valueType = QMetaType::type(name.left(name.size()-1));
-        QVariant var = variantValue(value);
+        QVariant &var = variantValue(value);
         if (valueType == var.userType()) {
             // We have T t, T* is requested, so return &t.
             *reinterpret_cast<void* *>(data) = var.data();
@@ -2235,10 +2235,9 @@ QObject *QV8Engine::qtObjectFromJS(v8::Handle<v8::Value> value)
 }
 
 
-QVariant QV8Engine::variantValue(v8::Handle<v8::Value> value)
+QVariant &QV8Engine::variantValue(v8::Handle<v8::Value> value)
 {
-    Q_ASSERT(isVariant(value));
-    return QV8Engine::toVariant(value, -1 /*whateever magic hint is*/);
+    return variantWrapper()->variantValue(value);
 }
 
 // Creates a QVariant wrapper object.
diff --git a/src/declarative/qml/v8/qv8engine_p.h b/src/declarative/qml/v8/qv8engine_p.h
index f20d867a81..43ef9821ac 100644
--- a/src/declarative/qml/v8/qv8engine_p.h
+++ b/src/declarative/qml/v8/qv8engine_p.h
@@ -387,7 +387,7 @@ public:
                                 const QByteArray &targetType,
                                 void **result);
 
-    QVariant variantValue(v8::Handle<v8::Value> value);
+    QVariant &variantValue(v8::Handle<v8::Value> value);
 
     QJSValue scriptValueFromInternal(v8::Handle<v8::Value>) const;
 
diff --git a/src/declarative/qml/v8/qv8variantwrapper.cpp b/src/declarative/qml/v8/qv8variantwrapper.cpp
index 27d0b3116b..de4f0ce2d7 100644
--- a/src/declarative/qml/v8/qv8variantwrapper.cpp
+++ b/src/declarative/qml/v8/qv8variantwrapper.cpp
@@ -159,7 +159,14 @@ QVariant QV8VariantWrapper::toVariant(QV8ObjectResource *r)
     return static_cast<QV8VariantResource *>(r)->data;
 }
 
-v8::Handle<v8::Value> QV8VariantWrapper::Getter(v8::Local<v8::String> property, 
+QVariant &QV8VariantWrapper::variantValue(v8::Handle<v8::Value> value)
+{
+    Q_ASSERT(isVariant(value));
+    QV8VariantResource *r =  v8_resource_cast<QV8VariantResource>(value->ToObject());
+    return static_cast<QV8VariantResource *>(r)->data;
+}
+
+v8::Handle<v8::Value> QV8VariantWrapper::Getter(v8::Local<v8::String> property,
                                                 const v8::AccessorInfo &info)
 {
     return v8::Handle<v8::Value>();
diff --git a/src/declarative/qml/v8/qv8variantwrapper_p.h b/src/declarative/qml/v8/qv8variantwrapper_p.h
index de74bc9e12..7e9924b3c0 100644
--- a/src/declarative/qml/v8/qv8variantwrapper_p.h
+++ b/src/declarative/qml/v8/qv8variantwrapper_p.h
@@ -74,6 +74,7 @@ public:
     bool isVariant(v8::Handle<v8::Value>);
     QVariant toVariant(v8::Handle<v8::Object>);
     QVariant toVariant(QV8ObjectResource *);
+    QVariant &variantValue(v8::Handle<v8::Value>);
 
 private:
     static v8::Handle<v8::Value> Getter(v8::Local<v8::String> property, 
diff --git a/tests/auto/declarative/qjsvalue/tst_qjsvalue.cpp b/tests/auto/declarative/qjsvalue/tst_qjsvalue.cpp
index 4eef465ddd..24330c9f2e 100644
--- a/tests/auto/declarative/qjsvalue/tst_qjsvalue.cpp
+++ b/tests/auto/declarative/qjsvalue/tst_qjsvalue.cpp
@@ -3705,11 +3705,7 @@ void tst_QJSValue::castToPointer()
         QJSValue v = eng.newVariant(int(123));
         int *ip = qjsvalue_cast<int*>(v);
         QVERIFY(ip != 0);
-#ifdef Q_WS_QPA
-        QEXPECT_FAIL("", "QTBUG-21000 fails", Abort);
-#endif
         QCOMPARE(*ip, 123);
-        QEXPECT_FAIL("", "Pointer magic for variants is currently not supported by QJSEngine", Abort);
         *ip = 456;
         QCOMPARE(qjsvalue_cast<int>(v), 456);