diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
--- a/src/MainWindow.cpp
+++ b/src/MainWindow.cpp
@@ -203,13 +203,13 @@
     layout()->setSpacing( 0 );
 
     //create main toolbar
-    m_mainToolbar = new MainToolbar( 0 );
+    m_mainToolbar = new MainToolbar( this );
     m_mainToolbar.data()->setAllowedAreas( Qt::TopToolBarArea | Qt::BottomToolBarArea );
     m_mainToolbar.data()->setMovable ( true );
     addToolBar( Qt::TopToolBarArea, m_mainToolbar.data() );
 
     //create slim toolbar
-    m_slimToolbar = new SlimToolbar( 0 );
+    m_slimToolbar = new SlimToolbar( this );
     m_slimToolbar.data()->setAllowedAreas( Qt::TopToolBarArea | Qt::BottomToolBarArea );
     m_slimToolbar.data()->setMovable ( true );
     addToolBar( Qt::TopToolBarArea, m_slimToolbar.data() );
@@ -1256,33 +1256,29 @@
 {
     DEBUG_BLOCK
 
-    if( locked )
-    {
-        m_browserDock.data()->setMovable( false );
-        m_contextDock.data()->setMovable( false );
-        m_playlistDock.data()->setMovable( false );
+    if( m_browserDock )
+        m_browserDock.data()->setMovable( !locked );
 
-        m_slimToolbar.data()->setFloatable( false );
-        m_slimToolbar.data()->setMovable( false );
+    if( m_contextDock )
+        m_contextDock.data()->setMovable( !locked );
 
-        m_mainToolbar.data()->setFloatable( false );
-        m_mainToolbar.data()->setMovable( false );
-    }
-    else
-    {
-        m_browserDock.data()->setMovable( true );
-        m_contextDock.data()->setMovable( true );
-        m_playlistDock.data()->setMovable( true );
+    if( m_playlistDock )
+        m_playlistDock.data()->setMovable( !locked );
 
-        m_slimToolbar.data()->setFloatable( true );
-        m_slimToolbar.data()->setMovable( true );
+    if( m_slimToolbar )
+    {
+        m_slimToolbar.data()->setFloatable( !locked );
+        m_slimToolbar.data()->setMovable( !locked );
+    }
 
-        m_mainToolbar.data()->setFloatable( true );
-        m_mainToolbar.data()->setMovable( true );
+    if( m_mainToolbar )
+    {
+        m_mainToolbar.data()->setFloatable( !locked );
+        m_mainToolbar.data()->setMovable( !locked );
     }
 
     AmarokConfig::setLockLayout( locked );
-    AmarokConfig::self()->writeConfig();
+    AmarokConfig::self()->save();
 }
 
 void
diff --git a/src/SvgHandler.cpp b/src/SvgHandler.cpp
--- a/src/SvgHandler.cpp
+++ b/src/SvgHandler.cpp
@@ -244,7 +244,8 @@
     //redraw entire app....
     reTint();
     m_cache->clear();
-    App::instance()->mainWindow()->update();
+    if( auto window = App::instance()->mainWindow() )
+        window->update();
 }
 
 QPixmap
diff --git a/src/browsers/CollectionTreeView.cpp b/src/browsers/CollectionTreeView.cpp
--- a/src/browsers/CollectionTreeView.cpp
+++ b/src/browsers/CollectionTreeView.cpp
@@ -145,6 +145,9 @@
             QQueue<QModelIndex> pendingIndices;
             while( !m_indicesToCheck.isEmpty() )
             {
+                if( !m_filterModel )
+                    return;
+
                 QModelIndex current = m_indicesToCheck.dequeue();
 
                 if( m_filterModel->canFetchMore( current ) )
@@ -174,7 +177,7 @@
         Q_DISABLE_COPY(AutoExpander)
 
         CollectionTreeView *m_treeView;
-        QAbstractItemModel *m_filterModel;
+        QPointer<QAbstractItemModel> m_filterModel;
         QQueue<QModelIndex> m_indicesToCheck;
 };
 
diff --git a/src/configdialog/ConfigDialog.h b/src/configdialog/ConfigDialog.h
--- a/src/configdialog/ConfigDialog.h
+++ b/src/configdialog/ConfigDialog.h
@@ -17,12 +17,13 @@
 #ifndef AMAROK2CONFIGDIALOG_H
 #define AMAROK2CONFIGDIALOG_H
 
-#include "ConfigDialogBase.h"
-
 #include <KConfigDialog>
 #include <KConfigSkeleton>
 #include <KWindowConfig>
 
+
+class ConfigDialogBase;
+
 class Amarok2ConfigDialog : public KConfigDialog
 {
     Q_OBJECT
@@ -48,15 +49,13 @@
         void updateButtons();
 
     protected Q_SLOTS:
-        void updateSettings();
-        void updateWidgets();
-        void updateWidgetsDefault();
-
-    private Q_SLOTS:
+        void updateSettings() Q_DECL_OVERRIDE;
+        void updateWidgets() Q_DECL_OVERRIDE;
+        void updateWidgetsDefault() Q_DECL_OVERRIDE;
 
     protected:
-        bool hasChanged();
-        bool isDefault();
+        bool hasChanged() Q_DECL_OVERRIDE;
+        bool isDefault() Q_DECL_OVERRIDE;
 
     private:
         QList<ConfigDialogBase*> m_pageList;
diff --git a/src/configdialog/ConfigDialog.cpp b/src/configdialog/ConfigDialog.cpp
--- a/src/configdialog/ConfigDialog.cpp
+++ b/src/configdialog/ConfigDialog.cpp
@@ -19,6 +19,7 @@
 #include "ConfigDialog.h"
 
 #include "amarokconfig.h"
+#include "ConfigDialogBase.h"
 #include "configdialog/dialogs/CollectionConfig.h"
 #include "configdialog/dialogs/DatabaseConfig.h"
 #include "configdialog/dialogs/GeneralConfig.h"
@@ -77,7 +78,7 @@
     okButton->setShortcut(Qt::CTRL | Qt::Key_Return);
     connect(buttonBox, &QDialogButtonBox::accepted, this, &Amarok2ConfigDialog::accept);
     connect(buttonBox, &QDialogButtonBox::rejected, this, &Amarok2ConfigDialog::reject);
-    mainLayout->addWidget(buttonBox);
+    setButtonBox(buttonBox);
     KWindowConfig::restoreWindowSize(windowHandle(), Amarok::config( "ConfigDialog" ));
 }
 
@@ -98,7 +99,7 @@
 
     KConfigGroup config = Amarok::config( "ConfigDialog" );
     KWindowConfig::saveWindowSize(windowHandle(), config);
-    AmarokConfig::self()->writeConfig();
+    AmarokConfig::self()->save();
 }
 
 void Amarok2ConfigDialog::updateButtons() //SLOT
diff --git a/src/configdialog/ConfigDialogBase.h b/src/configdialog/ConfigDialogBase.h
--- a/src/configdialog/ConfigDialogBase.h
+++ b/src/configdialog/ConfigDialogBase.h
@@ -19,6 +19,7 @@
 
 #include <QWidget>
 
+class Amarok2ConfigDialog;
 
 class ConfigDialogBase : public QWidget
 {
@@ -36,7 +37,7 @@
         virtual bool isDefault() = 0;
 
     protected:
-        ConfigDialogBase( QWidget* parent ) : QWidget( parent ) {}
+        ConfigDialogBase( Amarok2ConfigDialog* parent );
 };
 
 
diff --git a/src/configdialog/ConfigDialogBase.cpp b/src/configdialog/ConfigDialogBase.cpp
--- a/src/configdialog/ConfigDialogBase.cpp
+++ b/src/configdialog/ConfigDialogBase.cpp
@@ -15,4 +15,8 @@
  ****************************************************************************************/
 
 #include "ConfigDialogBase.h"
+#include "ConfigDialog.h"
 
+ConfigDialogBase::ConfigDialogBase(Amarok2ConfigDialog* parent) : QWidget(parent)
+{
+}
diff --git a/src/configdialog/dialogs/CollectionConfig.h b/src/configdialog/dialogs/CollectionConfig.h
--- a/src/configdialog/dialogs/CollectionConfig.h
+++ b/src/configdialog/dialogs/CollectionConfig.h
@@ -27,12 +27,12 @@
     Q_OBJECT
 
     public:
-        CollectionConfig( QWidget* parent );
+        CollectionConfig( Amarok2ConfigDialog* parent );
         virtual ~CollectionConfig();
 
-        virtual bool hasChanged();
-        virtual bool isDefault();
-        virtual void updateSettings();
+        bool hasChanged() Q_DECL_OVERRIDE;
+        bool isDefault() Q_DECL_OVERRIDE;
+        void updateSettings() Q_DECL_OVERRIDE;
 
     private:
         CollectionSetup* m_collectionSetup;
diff --git a/src/configdialog/dialogs/CollectionConfig.cpp b/src/configdialog/dialogs/CollectionConfig.cpp
--- a/src/configdialog/dialogs/CollectionConfig.cpp
+++ b/src/configdialog/dialogs/CollectionConfig.cpp
@@ -23,7 +23,7 @@
 #include "core-impl/collections/db/sql/SqlCollection.h"
 #include "dialogs/CollectionSetup.h"
 
-CollectionConfig::CollectionConfig( QWidget* parent )
+CollectionConfig::CollectionConfig( Amarok2ConfigDialog* parent )
     : ConfigDialogBase( parent )
 {
     m_collectionSetup = new CollectionSetup( this );
@@ -35,12 +35,10 @@
     KConfigGroup transcodeGroup = Amarok::config( Collections::SQL_TRANSCODING_GROUP_NAME );
     m_collectionSetup->transcodingConfig()->fillInChoices( Transcoding::Configuration::fromConfigGroup( transcodeGroup ) );
 
-    if (auto dialog = qobject_cast<Amarok2ConfigDialog*>(parent))
-    {
-        connect( m_collectionSetup, &CollectionSetup::changed, dialog, &Amarok2ConfigDialog::updateButtons );
-        connect( m_collectionSetup->transcodingConfig(), QOverload<int>::of(&QComboBox::currentIndexChanged),
-                 dialog, &Amarok2ConfigDialog::updateButtons );
-    }
+
+    connect( m_collectionSetup, &CollectionSetup::changed, parent, &Amarok2ConfigDialog::updateButtons );
+    connect( m_collectionSetup->transcodingConfig(), QOverload<int>::of(&QComboBox::currentIndexChanged),
+             parent, &Amarok2ConfigDialog::updateButtons );
 }
 
 CollectionConfig::~CollectionConfig()
diff --git a/src/configdialog/dialogs/DatabaseConfig.h b/src/configdialog/dialogs/DatabaseConfig.h
--- a/src/configdialog/dialogs/DatabaseConfig.h
+++ b/src/configdialog/dialogs/DatabaseConfig.h
@@ -29,12 +29,12 @@
     Q_OBJECT
 
     public:
-        DatabaseConfig( QWidget* parent, KConfigSkeleton *config );
+        DatabaseConfig( Amarok2ConfigDialog* parent, KConfigSkeleton *config );
         virtual ~DatabaseConfig();
 
-        virtual bool hasChanged();
-        virtual bool isDefault();
-        virtual void updateSettings();
+        virtual bool hasChanged() Q_DECL_OVERRIDE;
+        virtual bool isDefault() Q_DECL_OVERRIDE;
+        virtual void updateSettings() Q_DECL_OVERRIDE;
 
     public Q_SLOTS:
         void toggleExternalConfigAvailable( int checkBoxState );
diff --git a/src/configdialog/dialogs/DatabaseConfig.cpp b/src/configdialog/dialogs/DatabaseConfig.cpp
--- a/src/configdialog/dialogs/DatabaseConfig.cpp
+++ b/src/configdialog/dialogs/DatabaseConfig.cpp
@@ -25,7 +25,7 @@
 #include <KCMultiDialog>
 
 
-DatabaseConfig::DatabaseConfig( QWidget* parent, KConfigSkeleton *config )
+DatabaseConfig::DatabaseConfig( Amarok2ConfigDialog* parent, KConfigSkeleton *config )
     : ConfigDialogBase( parent )
     , m_configManager( new KConfigDialogManager( this, config ) )
 {
diff --git a/src/configdialog/dialogs/GeneralConfig.h b/src/configdialog/dialogs/GeneralConfig.h
--- a/src/configdialog/dialogs/GeneralConfig.h
+++ b/src/configdialog/dialogs/GeneralConfig.h
@@ -25,12 +25,12 @@
     Q_OBJECT
 
     public:
-        GeneralConfig( QWidget* parent );
+        GeneralConfig( Amarok2ConfigDialog* parent );
         virtual ~GeneralConfig();
 
-        virtual bool hasChanged();
-        virtual bool isDefault();
-        virtual void updateSettings();
+        bool hasChanged() Q_DECL_OVERRIDE;
+        bool isDefault() Q_DECL_OVERRIDE;
+        void updateSettings() Q_DECL_OVERRIDE;
 };
 
 #endif
diff --git a/src/configdialog/dialogs/GeneralConfig.cpp b/src/configdialog/dialogs/GeneralConfig.cpp
--- a/src/configdialog/dialogs/GeneralConfig.cpp
+++ b/src/configdialog/dialogs/GeneralConfig.cpp
@@ -17,7 +17,10 @@
 
 #include "GeneralConfig.h"
 
-GeneralConfig::GeneralConfig( QWidget* parent )
+#include "amarokconfig.h"
+
+
+GeneralConfig::GeneralConfig( Amarok2ConfigDialog* parent )
     : ConfigDialogBase( parent )
 {
     setupUi( this );
@@ -47,3 +50,5 @@
 {
 }
 
+
+
diff --git a/src/configdialog/dialogs/MetadataConfig.h b/src/configdialog/dialogs/MetadataConfig.h
--- a/src/configdialog/dialogs/MetadataConfig.h
+++ b/src/configdialog/dialogs/MetadataConfig.h
@@ -29,12 +29,12 @@
     Q_OBJECT
 
     public:
-        MetadataConfig( QWidget *parent );
+        MetadataConfig( Amarok2ConfigDialog *parent );
         virtual ~MetadataConfig();
 
-        virtual bool isDefault();
-        virtual bool hasChanged();
-        virtual void updateSettings();
+        bool isDefault() Q_DECL_OVERRIDE;
+        bool hasChanged() Q_DECL_OVERRIDE;
+        void updateSettings() Q_DECL_OVERRIDE;
 
     Q_SIGNALS:
         void changed();
diff --git a/src/configdialog/dialogs/MetadataConfig.cpp b/src/configdialog/dialogs/MetadataConfig.cpp
--- a/src/configdialog/dialogs/MetadataConfig.cpp
+++ b/src/configdialog/dialogs/MetadataConfig.cpp
@@ -27,11 +27,11 @@
 
 #include "MetaValues.h"
 
-MetadataConfig::MetadataConfig( QWidget *parent )
+MetadataConfig::MetadataConfig( Amarok2ConfigDialog *parent )
     : ConfigDialogBase( parent )
 {
-    if( auto p = static_cast<Amarok2ConfigDialog*>(parent) )
-        connect( this, &MetadataConfig::changed, p, &Amarok2ConfigDialog::updateButtons );
+    connect( this, &MetadataConfig::changed,
+             parent, &Amarok2ConfigDialog::updateButtons );
 
     setupUi( this );
 
@@ -150,7 +150,10 @@
 MetadataConfig::~MetadataConfig()
 {
     if( m_statSyncingConfig )
+    {
+        disconnect( this, &MetadataConfig::changed, 0, 0 );
         m_statSyncingConfig.data()->read(); // reset unsaved changes
+    }
 }
 
 bool
diff --git a/src/configdialog/dialogs/NotificationsConfig.h b/src/configdialog/dialogs/NotificationsConfig.h
--- a/src/configdialog/dialogs/NotificationsConfig.h
+++ b/src/configdialog/dialogs/NotificationsConfig.h
@@ -29,12 +29,12 @@
     Q_OBJECT
 
     public:
-        NotificationsConfig( QWidget* parent );
+        NotificationsConfig( Amarok2ConfigDialog* parent );
         virtual ~NotificationsConfig();
 
-        virtual bool hasChanged();
-        virtual bool isDefault();
-        virtual void updateSettings();
+        bool hasChanged() Q_DECL_OVERRIDE;
+        bool isDefault() Q_DECL_OVERRIDE;
+        void updateSettings() Q_DECL_OVERRIDE;
 
     Q_SIGNALS:
         void changed();
diff --git a/src/configdialog/dialogs/NotificationsConfig.cpp b/src/configdialog/dialogs/NotificationsConfig.cpp
--- a/src/configdialog/dialogs/NotificationsConfig.cpp
+++ b/src/configdialog/dialogs/NotificationsConfig.cpp
@@ -26,15 +26,15 @@
 
 #include <QDesktopWidget>
 
-NotificationsConfig::NotificationsConfig( QWidget* parent )
+NotificationsConfig::NotificationsConfig( Amarok2ConfigDialog* parent )
     : ConfigDialogBase( parent ) 
     , m_oldAlignment( static_cast<OSDWidget::Alignment>( AmarokConfig::osdAlignment() ) )
     , m_oldYOffset( AmarokConfig::osdYOffset() )
 {
     setupUi( this );
 
-    if (auto dialog = qobject_cast<Amarok2ConfigDialog*>(parent))
-        connect( this, &NotificationsConfig::changed, dialog, &Amarok2ConfigDialog::updateButtons );
+    connect( this, &NotificationsConfig::changed,
+             parent, &Amarok2ConfigDialog::updateButtons );
 
     m_osdPreview = new OSDPreviewWidget( this ); //must be child!!!
     m_osdPreview->setAlignment( static_cast<OSDWidget::Alignment>( AmarokConfig::osdAlignment() ) );
diff --git a/src/configdialog/dialogs/PlaybackConfig.h b/src/configdialog/dialogs/PlaybackConfig.h
--- a/src/configdialog/dialogs/PlaybackConfig.h
+++ b/src/configdialog/dialogs/PlaybackConfig.h
@@ -26,12 +26,12 @@
     Q_OBJECT
 
     public:
-        PlaybackConfig( QWidget* parent );
+        PlaybackConfig( Amarok2ConfigDialog* parent );
         virtual ~PlaybackConfig();
 
-        virtual bool hasChanged();
-        virtual bool isDefault();
-        virtual void updateSettings();
+        bool hasChanged() Q_DECL_OVERRIDE;
+        bool isDefault() Q_DECL_OVERRIDE;
+        void updateSettings() Q_DECL_OVERRIDE;
 
     private Q_SLOTS:
         void configurePhonon();
diff --git a/src/configdialog/dialogs/PlaybackConfig.cpp b/src/configdialog/dialogs/PlaybackConfig.cpp
--- a/src/configdialog/dialogs/PlaybackConfig.cpp
+++ b/src/configdialog/dialogs/PlaybackConfig.cpp
@@ -27,7 +27,7 @@
 #include <kmessagebox.h>
 
 
-PlaybackConfig::PlaybackConfig( QWidget* parent )
+PlaybackConfig::PlaybackConfig( Amarok2ConfigDialog* parent )
     : ConfigDialogBase( parent )
 {
     setupUi( this );
diff --git a/src/configdialog/dialogs/PluginsConfig.h b/src/configdialog/dialogs/PluginsConfig.h
--- a/src/configdialog/dialogs/PluginsConfig.h
+++ b/src/configdialog/dialogs/PluginsConfig.h
@@ -30,12 +30,12 @@
     Q_OBJECT
 
 public:
-    PluginsConfig( QWidget *parent );
+    PluginsConfig( Amarok2ConfigDialog *parent );
     virtual ~PluginsConfig();
 
-    virtual void updateSettings();
-    virtual bool hasChanged();
-    virtual bool isDefault();
+    void updateSettings() Q_DECL_OVERRIDE;
+    bool hasChanged() Q_DECL_OVERRIDE;
+    bool isDefault() Q_DECL_OVERRIDE;
 
 public Q_SLOTS:
     void slotConfigChanged( bool changed );
diff --git a/src/configdialog/dialogs/PluginsConfig.cpp b/src/configdialog/dialogs/PluginsConfig.cpp
--- a/src/configdialog/dialogs/PluginsConfig.cpp
+++ b/src/configdialog/dialogs/PluginsConfig.cpp
@@ -28,7 +28,7 @@
 
 #include <QVBoxLayout>
 
-PluginsConfig::PluginsConfig( QWidget *parent )
+PluginsConfig::PluginsConfig( Amarok2ConfigDialog *parent )
     : ConfigDialogBase( parent )
     , m_configChanged( false )
 {
@@ -51,8 +51,8 @@
 
     connect( m_selector, &KPluginSelector::changed, this, &PluginsConfig::slotConfigChanged );
 
-    if (auto dialog = qobject_cast<Amarok2ConfigDialog*>(parent))
-        connect( m_selector, &KPluginSelector::changed, dialog, &Amarok2ConfigDialog::updateButtons );
+    connect( m_selector, &KPluginSelector::changed,
+             parent, &Amarok2ConfigDialog::updateButtons );
 }
 
 PluginsConfig::~PluginsConfig()
diff --git a/src/configdialog/dialogs/ScriptsConfig.h b/src/configdialog/dialogs/ScriptsConfig.h
--- a/src/configdialog/dialogs/ScriptsConfig.h
+++ b/src/configdialog/dialogs/ScriptsConfig.h
@@ -36,12 +36,12 @@
     Q_OBJECT
 
 public:
-    ScriptsConfig( QWidget *parent );
+    ScriptsConfig( Amarok2ConfigDialog *parent );
     virtual ~ScriptsConfig();
 
-    virtual void updateSettings();
-    virtual bool hasChanged();
-    virtual bool isDefault();
+    void updateSettings() Q_DECL_OVERRIDE;
+    bool hasChanged() Q_DECL_OVERRIDE;
+    bool isDefault() Q_DECL_OVERRIDE;
 
 public Q_SLOTS:
     void slotConfigChanged( bool changed );
diff --git a/src/configdialog/dialogs/ScriptsConfig.cpp b/src/configdialog/dialogs/ScriptsConfig.cpp
--- a/src/configdialog/dialogs/ScriptsConfig.cpp
+++ b/src/configdialog/dialogs/ScriptsConfig.cpp
@@ -42,7 +42,7 @@
 #include <QMimeDatabase>
 #include <QMimeType>
 
-ScriptsConfig::ScriptsConfig( QWidget *parent )
+ScriptsConfig::ScriptsConfig( Amarok2ConfigDialog *parent )
     : ConfigDialogBase( parent )
     , m_configChanged( false )
     , m_parent( parent )
@@ -216,8 +216,8 @@
     connect( m_selector, &ScriptSelector::changed, this, &ScriptsConfig::slotConfigChanged );
     connect( m_selector, &ScriptSelector::filtered, m_uninstallButton, &QPushButton::setDisabled );
 
-    if (auto dialog = qobject_cast<Amarok2ConfigDialog*>(m_parent))
-        connect( m_selector, &ScriptSelector::changed, dialog, &Amarok2ConfigDialog::updateButtons );
+    connect( m_selector, &ScriptSelector::changed,
+             qobject_cast<Amarok2ConfigDialog*>(m_parent), &Amarok2ConfigDialog::updateButtons );
 
     m_verticalLayout->insertWidget( 0, m_selector );
     m_verticalLayout->removeWidget( m_oldSelector );
diff --git a/src/core-impl/collections/support/MemoryQueryMaker.cpp b/src/core-impl/collections/support/MemoryQueryMaker.cpp
--- a/src/core-impl/collections/support/MemoryQueryMaker.cpp
+++ b/src/core-impl/collections/support/MemoryQueryMaker.cpp
@@ -23,7 +23,6 @@
 #include "MemoryQueryMakerInternal.h"
 #include "core/support/Debug.h"
 
-#include <ThreadWeaver/QObjectDecorator>
 #include <ThreadWeaver/Queue>
 
 #include <QList>
diff --git a/src/core-impl/meta/proxy/MetaProxyWorker.h b/src/core-impl/meta/proxy/MetaProxyWorker.h
--- a/src/core-impl/meta/proxy/MetaProxyWorker.h
+++ b/src/core-impl/meta/proxy/MetaProxyWorker.h
@@ -62,7 +62,6 @@
         private Q_SLOTS:
             void slotNewTrackProvider( Collections::TrackProvider *newTrackProvider );
             void slotNewCollection( Collections::Collection *newCollection );
-            void slotStepDone();
 
         private:
             QUrl m_url;
diff --git a/src/core-impl/meta/proxy/MetaProxyWorker.cpp b/src/core-impl/meta/proxy/MetaProxyWorker.cpp
--- a/src/core-impl/meta/proxy/MetaProxyWorker.cpp
+++ b/src/core-impl/meta/proxy/MetaProxyWorker.cpp
@@ -28,8 +28,6 @@
     , m_provider( provider )
     , m_stepsDoneReceived( 0 )
 {
-    connect( this, &Worker::done, this, &Worker::slotStepDone );
-    connect( this, &Worker::finishedLookup, this, &Worker::slotStepDone );
 }
 
 void
@@ -100,11 +98,3 @@
 {
     slotNewTrackProvider( newCollection );
 }
-
-void
-Worker::slotStepDone()
-{
-    m_stepsDoneReceived++;
-    if( m_stepsDoneReceived >= 2 )
-        deleteLater();
-}
diff --git a/src/core-impl/storage/sql/mysql-shared/MySqlStorage.cpp b/src/core-impl/storage/sql/mysql-shared/MySqlStorage.cpp
--- a/src/core-impl/storage/sql/mysql-shared/MySqlStorage.cpp
+++ b/src/core-impl/storage/sql/mysql-shared/MySqlStorage.cpp
@@ -50,9 +50,10 @@
 
         countMutex.lock();
         threadsCount++;
-        countMutex.unlock();
 
-        debug() << "Initialized thread, count==" << threadsCount;
+        debug() << "Initialized thread, count ==" << threadsCount;
+
+        countMutex.unlock();
     }
 
 public:
@@ -65,12 +66,13 @@
 
         countMutex.lock();
         threadsCount--;
-        countMutex.unlock();
 
-        debug() << "Deinitialized thread, count==" << threadsCount;
+        debug() << "Deinitialized thread, count ==" << threadsCount;
 
         if( threadsCount == 0 )
             mysql_library_end();
+
+        countMutex.unlock();
     }
 
     static void init()
diff --git a/src/core-impl/storage/sql/mysqlestorage/MySqlEmbeddedStorage.cpp b/src/core-impl/storage/sql/mysqlestorage/MySqlEmbeddedStorage.cpp
--- a/src/core-impl/storage/sql/mysqlestorage/MySqlEmbeddedStorage.cpp
+++ b/src/core-impl/storage/sql/mysqlestorage/MySqlEmbeddedStorage.cpp
@@ -43,7 +43,6 @@
 bool
 MySqlEmbeddedStorage::init( const QString &storageLocation )
 {
-
     // -- figuring out and setting the database path.
     QString storagePath = storageLocation;
     QString databaseDir;
@@ -142,10 +141,7 @@
     if( m_db )
     {
         mysql_close( m_db );
-        if( !libraryInitRef.deref() )
-        {
-            mysql_library_end();
-        }
+        libraryInitRef.deref();
     }
 }
 
diff --git a/src/core-impl/storage/sql/mysqlserverstorage/MySqlServerStorage.cpp b/src/core-impl/storage/sql/mysqlserverstorage/MySqlServerStorage.cpp
--- a/src/core-impl/storage/sql/mysqlserverstorage/MySqlServerStorage.cpp
+++ b/src/core-impl/storage/sql/mysqlserverstorage/MySqlServerStorage.cpp
@@ -117,10 +117,7 @@
     if( m_db )
     {
         mysql_close( m_db );
-        if( !libraryInitRef.deref() )
-        {
-            mysql_library_end();
-        }
+        libraryInitRef.deref();
     }
 }
 
diff --git a/src/playlistgenerator/Preset.cpp b/src/playlistgenerator/Preset.cpp
--- a/src/playlistgenerator/Preset.cpp
+++ b/src/playlistgenerator/Preset.cpp
@@ -157,8 +157,6 @@
     } else {
         debug() << "Ignoring results from aborted Solver" << solver->serial();
     }
-    ThreadWeaver::QObjectDecorator *qs = new ThreadWeaver::QObjectDecorator(job.data());
-    qs->deleteLater();
 
     emit lock( false );
 }
diff --git a/src/statusbar/ProgressBar.h b/src/statusbar/ProgressBar.h
--- a/src/statusbar/ProgressBar.h
+++ b/src/statusbar/ProgressBar.h
@@ -73,7 +73,6 @@
 
     Q_SIGNALS:
         void cancelled( ProgressBar * );
-//         void cancelled();
         void complete( ProgressBar * );
         void percentageChanged( int );
 
diff --git a/src/statusbar/ProgressBar.cpp b/src/statusbar/ProgressBar.cpp
--- a/src/statusbar/ProgressBar.cpp
+++ b/src/statusbar/ProgressBar.cpp
@@ -84,7 +84,7 @@
 {
     cancelButton()->setHidden( false );
     if( receiver )
-        connect( this, SIGNAL(cancelled()), receiver, slot, type );
+        connect( this, SIGNAL(cancelled(ProgressBar*)), receiver, slot, type );
     connect( cancelButton(), &QAbstractButton::clicked, this, &ProgressBar::cancel );
 
     return this;
@@ -94,7 +94,6 @@
 {
     DEBUG_BLOCK
     debug() << "cancelling operation: " << m_descriptionLabel->text();
-//     emit( cancelled() );
     emit( cancelled( this ) );
 }