Null pointer check for the layer tree

rldhont · rldhont · commit 388f8630f36a · 2017-09-19T09:23:24.000+02:00
diff --git a/src/core/layertree/qgslayertreemodellegendnode.cpp b/src/core/layertree/qgslayertreemodellegendnode.cpp
@@ -137,6 +137,7 @@ QgsSymbolLegendNode::QgsSymbolLegendNode( QgsLayerTreeLayer *nodeLayer, const Qg
 {
   updateLabel();
   connect( qobject_cast<QgsVectorLayer *>( nodeLayer->layer() ), &QgsVectorLayer::symbolFeatureCountMapChanged, this, &QgsSymbolLegendNode::updateLabel );
+  connect( nodeLayer, &QObject::destroyed, this, [ = ]() { mLayerNode = nullptr; } );
 
   if ( mItem.symbol() )
     mSymbolUsesMapUnits = ( mItem.symbol()->outputUnit() != QgsUnitTypes::RenderMillimeters );
@@ -444,6 +445,9 @@ void QgsSymbolLegendNode::invalidateMapBasedData()
 
 void QgsSymbolLegendNode::updateLabel()
 {
+  if ( !mLayerNode )
+    return;
+
   bool showFeatureCount = mLayerNode->customProperty( QStringLiteral( "showFeatureCount" ), 0 ).toBool();
   QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( mLayerNode->layer() );
 

Original file line number	Diff line number	Diff line change
`@@ -137,6 +137,7 @@ QgsSymbolLegendNode::QgsSymbolLegendNode( QgsLayerTreeLayer *nodeLayer, const Qg`
`137`	`137`	`{`
`138`	`138`	`updateLabel();`
`139`	`139`	`connect( qobject_cast<QgsVectorLayer *>( nodeLayer->layer() ), &QgsVectorLayer::symbolFeatureCountMapChanged, this, &QgsSymbolLegendNode::updateLabel );`
	`140`	`+ connect( nodeLayer, &QObject::destroyed, this, [ = ]() { mLayerNode = nullptr; } );`
`140`	`141`
`141`	`142`	`if ( mItem.symbol() )`
`142`	`143`	`mSymbolUsesMapUnits = ( mItem.symbol()->outputUnit() != QgsUnitTypes::RenderMillimeters );`
`@@ -444,6 +445,9 @@ void QgsSymbolLegendNode::invalidateMapBasedData()`
`444`	`445`
`445`	`446`	`void QgsSymbolLegendNode::updateLabel()`
`446`	`447`	`{`
	`448`	`+ if ( !mLayerNode )`
	`449`	`+ return;`
	`450`	`+`
`447`	`451`	`bool showFeatureCount = mLayerNode->customProperty( QStringLiteral( "showFeatureCount" ), 0 ).toBool();`
`448`	`452`	`QgsVectorLayer vl = qobject_cast<QgsVectorLayer >( mLayerNode->layer() );`
`449`	`453`