v4: Enable primitive conversation to QQmlScriptString in javascript

This makes following QML-code proper working:

ParentChange {
  x: 0
  Component.onCompleted: x = 10
}

where x is a QQmlScriptString.

Before this patch an error-message would be thrown that the
bool/int/string/etc cannot be converted to a QQmlScriptString.

With the patch primitive types including null and undefined are
proper converted to a QQmlScriptString. The patch ignores (as
in not implements) function/binding assignment.

Unfortunately since commit aa25ad8d5f4 its not possible any
longer to instanciate QQmlScriptString what means there is
otherwise no (easy) way to inject a QQmlScriptString from
within Javascript.

Change-Id: I18aac6a6e9a57f3b7d0a2d66cdab2be6c3c153c5
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

4 files changed, 20 insertions, 2 deletions

diff --git a/src/qml/compiler/qv4compileddata.cpp b/src/qml/compiler/qv4compileddata.cpp
index cd9d8fe8a9..01561eb566 100644
--- a/src/qml/compiler/qv4compileddata.cpp
+++ b/src/qml/compiler/qv4compileddata.cpp
@@ -233,7 +233,7 @@ QString Binding::valueAsString(const Unit *unit) const
 }
 
 //reverse of Lexer::singleEscape()
-static QString escapedString(const QString &string)
+QString Binding::escapedString(const QString &string)
 {
     QString tmp = QLatin1String("\"");
     for (int i = 0; i < string.length(); ++i) {
diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index 869caad8bd..78b7b4692d 100644
--- a/src/qml/compiler/qv4compileddata_p.h
+++ b/src/qml/compiler/qv4compileddata_p.h
@@ -284,6 +284,8 @@ struct Q_QML_PRIVATE_EXPORT Binding
         return false;
     }
 
+    static QString escapedString(const QString &string);
+
     bool evaluatesToString() const { return type == Type_String || type == Type_Translation || type == Type_TranslationById; }
 
     QString valueAsString(const Unit *unit) const;
diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index e12b8f1756..c5c04c0a56 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -65,6 +65,8 @@
 #include <private/qv4regexpobject_p.h>
 #include <private/qv4scopedvalue_p.h>
 #include <private/qv4mm_p.h>
+#include <private/qqmlscriptstring_p.h>
+#include <private/qv4compileddata_p.h>
 
 #include <QtQml/qjsvalue.h>
 #include <QtCore/qjsonarray.h>
@@ -511,7 +513,7 @@ void QObjectWrapper::setProperty(QObject *object, ExecutionContext *ctx, QQmlPro
         PROPERTY_STORE(QJsonValue, QJsonValue(QJsonValue::Undefined));
     } else if (!newBinding && property->propType == qMetaTypeId<QJSValue>()) {
         PROPERTY_STORE(QJSValue, new QJSValuePrivate(ctx->d()->engine, value));
-    } else if (value->isUndefined()) {
+    } else if (value->isUndefined() && property->propType != qMetaTypeId<QQmlScriptString>()) {
         QString error = QLatin1String("Cannot assign [undefined] to ");
         if (!QMetaType::typeName(property->propType))
             error += QLatin1String("[unknown property type]");
@@ -535,6 +537,16 @@ void QObjectWrapper::setProperty(QObject *object, ExecutionContext *ctx, QQmlPro
         QQmlVMEMetaObject *vmemo = QQmlVMEMetaObject::get(object);
         Q_ASSERT(vmemo);
         vmemo->setVMEProperty(property->coreIndex, value);
+    } else if (property->propType == qMetaTypeId<QQmlScriptString>() && (value->isUndefined() || value->isPrimitive())) {
+        QQmlScriptString ss(value->toQStringNoThrow(), 0 /* context */, object);
+        if (value->isNumber()) {
+            ss.d->numberValue = value->toNumber();
+            ss.d->isNumberLiteral = true;
+        } else if (value->isString()) {
+            ss.d->script = QV4::CompiledData::Binding::escapedString(ss.d->script);
+            ss.d->isStringLiteral = true;
+        }
+        PROPERTY_STORE(QQmlScriptString, ss);
     } else {
         QVariant v;
         if (property->isQList())
diff --git a/src/qml/qml/qqmlscriptstring.h b/src/qml/qml/qqmlscriptstring.h
index 2c10df6efc..d85df0e867 100644
--- a/src/qml/qml/qqmlscriptstring.h
+++ b/src/qml/qml/qqmlscriptstring.h
@@ -54,6 +54,9 @@ class QObject;
 class QQmlContext;
 class QQmlScriptStringPrivate;
 class QQmlObjectCreator;
+namespace QV4 {
+    struct QObjectWrapper;
+}
 class Q_QML_EXPORT QQmlScriptString
 {
 public:
@@ -79,6 +82,7 @@ private:
     friend class QQmlScriptStringPrivate;
     friend class QQmlExpression;
     friend class QQmlBinding;
+    friend struct QV4::QObjectWrapper;
 };
 
 QT_END_NAMESPACE