Cleanup some default values from nullptr to empty non-pointers

Author: dakcarto

src/core/layertree/qgslayertreemodel.cpp

@@ -309,7 +309,7 @@ Qt::ItemFlags QgsLayerTreeModel::flags( const QModelIndex& index ) const
 {
   if ( !index.isValid() )
   {
-    Qt::ItemFlags rootFlags = nullptr;
+    Qt::ItemFlags rootFlags = Qt::ItemFlags();
     if ( testFlag( AllowNodeReorder ) )
       rootFlags |= Qt::ItemIsDropEnabled;
     return rootFlags;

src/core/qgsbrowsermodel.cpp

@@ -181,7 +181,7 @@ void QgsBrowserModel::removeRootItems()
 Qt::ItemFlags QgsBrowserModel::flags( const QModelIndex & index ) const
 {
   if ( !index.isValid() )
-    return nullptr;
+    return Qt::ItemFlags();
 
   Qt::ItemFlags flags = Qt::ItemIsEnabled | Qt::ItemIsSelectable;
 

src/core/qgscoordinatereferencesystem.cpp

@@ -1325,7 +1325,7 @@ QString QgsCoordinateReferenceSystem::proj4FromSrsId( const int theSrsId )
     if ( !myFileInfo.exists() ) //its unlikely that this condition will ever be reached
     {
       QgsDebugMsg( "users qgis.db not found" );
-      return nullptr;
+      return QString();
     }
   }
   else //must be  a system projection then

src/core/qgsproviderregistry.h

@@ -80,7 +80,7 @@ class CORE_EXPORT QgsProviderRegistry
     int providerCapabilities( const QString& providerKey ) const;
 
     QWidget *selectWidget( const QString & providerKey,
-                           QWidget * parent = nullptr, const Qt::WindowFlags& fl = nullptr );
+                           QWidget * parent = nullptr, const Qt::WindowFlags& fl = Qt::WindowFlags() );
 
 #if QT_VERSION >= 0x050000
     /** Get pointer to provider function

src/core/symbology-ng/qgscptcityarchive.cpp

@@ -1372,7 +1372,7 @@ void QgsCptCityBrowserModel::removeRootItems()
 Qt::ItemFlags QgsCptCityBrowserModel::flags( const QModelIndex & index ) const
 {
   if ( !index.isValid() )
-    return nullptr;
+    return Qt::ItemFlags();
 
   Qt::ItemFlags flags = Qt::ItemIsEnabled | Qt::ItemIsSelectable;
 

src/core/symbology-ng/qgssinglesymbolrendererv2.cpp

@@ -423,11 +423,11 @@ QgsLegendSymbolListV2 QgsSingleSymbolRendererV2::legendSymbolItemsV2() const
       QgsScaleExpression scaleExp( sizeDD.expressionString() );
       if ( scaleExp.type() != QgsScaleExpression::Unknown )
       {
-        QgsLegendSymbolItemV2 title( nullptr, scaleExp.baseExpression(), nullptr );
+        QgsLegendSymbolItemV2 title( nullptr, scaleExp.baseExpression(), QString() );
         lst << title;
         Q_FOREACH ( double v, QgsSymbolLayerV2Utils::prettyBreaks( scaleExp.minValue(), scaleExp.maxValue(), 4 ) )
         {
-          QgsLegendSymbolItemV2 si( mSymbol.data(), QString::number( v ), nullptr );
+          QgsLegendSymbolItemV2 si( mSymbol.data(), QString::number( v ), QString() );
           QgsMarkerSymbolV2 * s = static_cast<QgsMarkerSymbolV2 *>( si.symbol() );
           s->setDataDefinedSize( 0 );
           s->setSize( scaleExp.size( v ) );
@@ -438,7 +438,7 @@ QgsLegendSymbolListV2 QgsSingleSymbolRendererV2::legendSymbolItemsV2() const
     }
   }
 
-  lst << QgsLegendSymbolItemV2( mSymbol.data(), QString(), nullptr );
+  lst << QgsLegendSymbolItemV2( mSymbol.data(), QString(), QString() );
   return lst;
 }