Make sure component wrapper is not deleted in advance

Use ScriptEngine::newQObject instead of the stock QScriptEngine one.
This one (among other things) sets object ownership to Cpp, preventing
dubious "cannot call name on undefined" script failures if the garbage
collector runs.

Change-Id: Ib3275012d307533c13de3520f4630d1eeee66869
Reviewed-by: Niels Weber <niels.weber@theqtcompany.com>

2 files changed, 16 insertions, 11 deletions

diff --git a/src/libs/installer/scriptengine.cpp b/src/libs/installer/scriptengine.cpp
index 0d41e812d..6d776db88 100644
--- a/src/libs/installer/scriptengine.cpp
+++ b/src/libs/installer/scriptengine.cpp
@@ -294,6 +294,13 @@ namespace QInstaller {
     \qmlsignal gui::settingsButtonClicked();
 */
 
+QJSValue InstallerProxy::componentByName(const QString &componentName)
+{
+    if (m_core)
+        return m_engine->newQObject(m_core->componentByName(componentName));
+    return QJSValue();
+}
+
 GuiProxy::GuiProxy(ScriptEngine *engine, QObject *parent) :
     QObject(parent),
     m_engine(engine),
@@ -503,7 +510,7 @@ ScriptEngine::ScriptEngine(PackageManagerCore *core) :
     QJSValue global = m_engine.globalObject();
     global.setProperty(QLatin1String("console"), m_engine.newQObject(new ConsoleProxy));
     global.setProperty(QLatin1String("QFileDialog"), m_engine.newQObject(new QFileDialogProxy));
-    const QJSValue proxy = m_engine.newQObject(new InstallerProxy(&m_engine, core));
+    const QJSValue proxy = m_engine.newQObject(new InstallerProxy(this, core));
     global.setProperty(QLatin1String("InstallerProxy"), proxy);
     global.setProperty(QLatin1String("print"), m_engine.newQObject(new ConsoleProxy)
         .property(QLatin1String("log")));
@@ -558,6 +565,9 @@ ScriptEngine::ScriptEngine(PackageManagerCore *core) :
 QJSValue ScriptEngine::newQObject(QObject *object)
 {
     QJSValue jsValue = m_engine.newQObject(object);
+    if (!jsValue.isQObject())
+        return jsValue;
+
     QQmlEngine::setObjectOwnership(object, QQmlEngine::CppOwnership);
 
     // add findChild(), findChildren() methods known from QtScript
diff --git a/src/libs/installer/scriptengine_p.h b/src/libs/installer/scriptengine_p.h
index 696073703..eeb547a78 100644
--- a/src/libs/installer/scriptengine_p.h
+++ b/src/libs/installer/scriptengine_p.h
@@ -1,6 +1,6 @@
 /**************************************************************************
 **
-** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Copyright (C) 2015 Digia Plc and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the Qt Installer Framework.
@@ -42,7 +42,6 @@
 #include <QDebug>
 #include <QDesktopServices>
 #include <QFileDialog>
-#include <QJSEngine>
 #include <QStandardPaths>
 
 namespace QInstaller {
@@ -65,18 +64,14 @@ class InstallerProxy : public QObject
     Q_DISABLE_COPY(InstallerProxy)
 
 public:
-    InstallerProxy(QJSEngine *engine, PackageManagerCore *core)
+    InstallerProxy(ScriptEngine *engine, PackageManagerCore *core)
         : m_engine(engine), m_core(core) {}
 
-public slots :
-    QJSValue componentByName(const QString &componentName) {
-        if (m_core)
-            return m_engine->newQObject(m_core->componentByName(componentName));
-        return QJSValue();
-    }
+public slots:
+    QJSValue componentByName(const QString &componentName);
 
 private:
-    QJSEngine *m_engine;
+    ScriptEngine *m_engine;
     PackageManagerCore *m_core;
 };