Fix crash when editing marker through symbol manager (fix #13077)

Author: nyalldawson

src/gui/symbology-ng/qgsrendererv2widget.h

@@ -57,24 +57,24 @@ class GUI_EXPORT QgsRendererV2Widget : public QWidget
     QAction* mCopyAction;
     QAction* mPasteAction;
 
-    /**Subclasses may provide the capability of changing multiple symbols at once by implementing the following two methods
+    /** Subclasses may provide the capability of changing multiple symbols at once by implementing the following two methods
       and by connecting the slot contextMenuViewCategories(const QPoint&)*/
     virtual QList<QgsSymbolV2*> selectedSymbols() { return QList<QgsSymbolV2*>(); }
     virtual void refreshSymbolView() {}
 
   protected slots:
     void  contextMenuViewCategories( const QPoint& p );
-    /**Change color of selected symbols*/
+    /** Change color of selected symbols*/
     void changeSymbolColor();
-    /**Change opacity of selected symbols*/
+    /** Change opacity of selected symbols*/
     void changeSymbolTransparency();
-    /**Change units mm/map units of selected symbols*/
+    /** Change units mm/map units of selected symbols*/
     void changeSymbolUnit();
-    /**Change line widths of selected symbols*/
+    /** Change line widths of selected symbols*/
     void changeSymbolWidth();
-    /**Change marker sizes of selected symbols*/
+    /** Change marker sizes of selected symbols*/
     void changeSymbolSize();
-    /**Change marker angles of selected symbols*/
+    /** Change marker angles of selected symbols*/
     void changeSymbolAngle();
 
     virtual void copy() {}
@@ -173,7 +173,7 @@ class GUI_EXPORT QgsDataDefinedSizeDialog : public QgsDataDefinedValueDialog
         : QgsDataDefinedValueDialog( symbolList, layer, tr( "Size" ) )
     {
       init( tr( "Symbol size" ) );
-      if ( symbolList.length() )
+      if ( symbolList.length() && mLayer )
         mDDBtn->setAssistant( tr( "Size Assistant..." ), new QgsSizeScaleWidget( mLayer, static_cast<const QgsMarkerSymbolV2*>( symbolList[0] ) ) );
     }
 

src/gui/symbology-ng/qgssizescalewidget.cpp

@@ -82,13 +82,20 @@ QgsSizeScaleWidget::QgsSizeScaleWidget( const QgsVectorLayer * layer, const QgsM
     : mSymbol( symbol )
     // we just use the minimumValue and maximumValue from the layer, unfortunately they are
     // non const, so we get the layer from the registry instead
-    , mLayer( dynamic_cast<QgsVectorLayer *>( QgsMapLayerRegistry::instance()->mapLayer( layer->id() ) ) )
+    , mLayer( layer ? dynamic_cast<QgsVectorLayer *>( QgsMapLayerRegistry::instance()->mapLayer( layer->id() ) ) : 0 )
 {
   setupUi( this );
   setWindowFlags( Qt::WindowStaysOnTopHint );
 
-  mLayerTreeLayer = new QgsLayerTreeLayer( mLayer );
-  mRoot.addChildNode( mLayerTreeLayer ); // takes ownership
+  if ( mLayer )
+  {
+    mLayerTreeLayer = new QgsLayerTreeLayer( mLayer );
+    mRoot.addChildNode( mLayerTreeLayer ); // takes ownership
+  }
+  else
+  {
+    mLayerTreeLayer = 0;
+  }
 
   treeView->setModel( &mPreviewList );
   treeView->setItemDelegate( new ItemDelegate( &mPreviewList ) );
@@ -104,7 +111,10 @@ QgsSizeScaleWidget::QgsSizeScaleWidget( const QgsVectorLayer * layer, const QgsM
   connect( computeValuesButton, SIGNAL( clicked() ), computeValuesButton, SLOT( showMenu() ) );
 
   //mExpressionWidget->setFilters( QgsFieldProxyModel::Numeric | QgsFieldProxyModel::Date );
-  mExpressionWidget->setLayer( mLayer );
+  if ( mLayer )
+  {
+    mExpressionWidget->setLayer( mLayer );
+  }
 
   scaleMethodComboBox->addItem( tr( "Flannery" ), int( QgsScaleExpression::Flannery ) );
   scaleMethodComboBox->addItem( tr( "Surface" ), int( QgsScaleExpression::Area ) );
@@ -153,7 +163,7 @@ QgsScaleExpression *QgsSizeScaleWidget::createExpression() const
 
 void QgsSizeScaleWidget::updatePreview()
 {
-  if ( !mSymbol )
+  if ( !mSymbol || !mLayer )
     return;
 
   QScopedPointer<QgsScaleExpression> expr( createExpression() );
@@ -193,6 +203,9 @@ void QgsSizeScaleWidget::updatePreview()
 
 void QgsSizeScaleWidget::computeFromLayerTriggered()
 {
+  if ( !mLayer )
+    return;
+
   QgsExpression expression( mExpressionWidget->currentField() );
   if ( ! expression.prepare( mLayer->pendingFields() ) )
     return;

src/gui/symbology-ng/qgssymbollayerv2widget.cpp

@@ -338,7 +338,8 @@ QgsSimpleMarkerSymbolLayerV2Widget::QgsSimpleMarkerSymbolLayerV2Widget( const Qg
   //make a temporary symbol for the size assistant preview
   mAssistantPreviewSymbol = new QgsMarkerSymbolV2();
 
-  mSizeDDBtn->setAssistant( tr( "Size Assistant..." ), new QgsSizeScaleWidget( mVectorLayer, mAssistantPreviewSymbol ) );
+  if ( mVectorLayer )
+    mSizeDDBtn->setAssistant( tr( "Size Assistant..." ), new QgsSizeScaleWidget( mVectorLayer, mAssistantPreviewSymbol ) );
 
   QSize size = lstNames->iconSize();
   QStringList names;
@@ -1538,7 +1539,8 @@ QgsSvgMarkerSymbolLayerV2Widget::QgsSvgMarkerSymbolLayerV2Widget( const QgsVecto
 
   //make a temporary symbol for the size assistant preview
   mAssistantPreviewSymbol = new QgsMarkerSymbolV2();
-  mSizeDDBtn->setAssistant( tr( "Size Assistant..." ), new QgsSizeScaleWidget( mVectorLayer, mAssistantPreviewSymbol ) );
+  if ( mVectorLayer )
+    mSizeDDBtn->setAssistant( tr( "Size Assistant..." ), new QgsSizeScaleWidget( mVectorLayer, mAssistantPreviewSymbol ) );
 }
 
 QgsSvgMarkerSymbolLayerV2Widget::~QgsSvgMarkerSymbolLayerV2Widget()
@@ -2504,7 +2506,8 @@ QgsFontMarkerSymbolLayerV2Widget::QgsFontMarkerSymbolLayerV2Widget( const QgsVec
   //make a temporary symbol for the size assistant preview
   mAssistantPreviewSymbol = new QgsMarkerSymbolV2();
 
-  mSizeDDBtn->setAssistant( tr( "Size Assistant..." ), new QgsSizeScaleWidget( mVectorLayer, mAssistantPreviewSymbol ) );
+  if ( mVectorLayer )
+    mSizeDDBtn->setAssistant( tr( "Size Assistant..." ), new QgsSizeScaleWidget( mVectorLayer, mAssistantPreviewSymbol ) );
 
   connect( cboFont, SIGNAL( currentFontChanged( const QFont & ) ), this, SLOT( setFontFamily( const QFont& ) ) );
   connect( spinSize, SIGNAL( valueChanged( double ) ), this, SLOT( setSize( double ) ) );