Merge pull request #482 from matthias-kuhn/fix-7379

Fix issue #7379: Crash when attribute table is closed after layer has be...

Author: jef-n

src/core/qgsvectorlayercache.cpp

@@ -27,6 +27,7 @@ QgsVectorLayerCache::QgsVectorLayerCache( QgsVectorLayer* layer, int cacheSize,
 
   connect( mLayer, SIGNAL( featureDeleted( QgsFeatureId ) ), SLOT( featureDeleted( QgsFeatureId ) ) );
   connect( mLayer, SIGNAL( featureAdded( QgsFeatureId ) ), SLOT( featureAdded( QgsFeatureId ) ) );
+  connect( mLayer, SIGNAL( layerDeleted() ), SLOT( layerDeleted() ) );
 
   setCacheGeometry( true );
   setCacheSubsetOfAttributes( mLayer->pendingAllAttributesList() );
@@ -228,6 +229,13 @@ void QgsVectorLayerCache::geometryChanged( QgsFeatureId fid, QgsGeometry& geom )
   }
 }
 
+void QgsVectorLayerCache::layerDeleted()
+{
+  emit ( cachedLayerDeleted() );
+
+  mLayer = NULL;
+}
+
 QgsFeatureIterator QgsVectorLayerCache::getFeatures( const QgsFeatureRequest &featureRequest )
 {
   QgsFeatureIterator it;

src/core/qgsvectorlayercache.h

@@ -209,13 +209,21 @@ class CORE_EXPORT QgsVectorLayerCache : public QObject
      */
     void progress( int i, bool& cancel );
 
+    /**
+     * @brief Is emitted when the cached layer is deleted. Is emitted when the cached layers layerDelete()
+     * signal is being emitted, but before the local reference to it has been set to NULL. So call to
+     * @link {layer()} will still return a valid pointer for cleanup purpose.
+     */
+    void cachedLayerDeleted();
+
   public slots:
     void attributeValueChanged( QgsFeatureId fid, int field, const QVariant& value );
     void featureDeleted( QgsFeatureId fid );
     void featureAdded( QgsFeatureId fid );
     void attributeAdded( int field );
     void attributeDeleted( int field );
     void geometryChanged( QgsFeatureId fid, QgsGeometry& geom );
+    void layerDeleted();
 
   private:
 

src/gui/attributetable/qgsattributetablefiltermodel.cpp

@@ -242,6 +242,9 @@ void QgsAttributeTableFilterModel::announcedInvalidateFilter()
 
 void QgsAttributeTableFilterModel::generateListOfVisibleFeatures()
 {
+  if ( !layer() )
+    return;
+
   bool filter = false;
   QgsRectangle rect = mCanvas->mapRenderer()->mapToLayerCoordinates( layer(), mCanvas->extent() );
   QgsRenderContext renderContext;

src/gui/attributetable/qgsattributetablemodel.cpp

@@ -45,17 +45,21 @@ QgsAttributeTableModel::QgsAttributeTableModel( QgsVectorLayerCache *layerCache,
   connect( layer(), SIGNAL( featureDeleted( QgsFeatureId ) ), this, SLOT( featureDeleted( QgsFeatureId ) ) );
   connect( layer(), SIGNAL( attributeAdded( int ) ), this, SLOT( attributeAdded( int ) ) );
   connect( layer(), SIGNAL( attributeDeleted( int ) ), this, SLOT( attributeDeleted( int ) ) );
+  connect( mLayerCache, SIGNAL( cachedLayerDeleted() ), this, SLOT( layerDeleted() ) );
 }
 
 QgsAttributeTableModel::~QgsAttributeTableModel()
 {
-  const QgsFields& fields = layer()->pendingFields();
-  for ( int idx = 0; idx < fields.count(); ++idx )
+  if ( layer() )
   {
-    if ( layer()->editType( idx ) != QgsVectorLayer::ValueRelation )
-      continue;
+    const QgsFields& fields = layer()->pendingFields();
+    for ( int idx = 0; idx < fields.count(); ++idx )
+    {
+      if ( layer()->editType( idx ) != QgsVectorLayer::ValueRelation )
+        continue;
 
-    delete mValueMaps.take( idx );
+      delete mValueMaps.take( idx );
+    }
   }
 }
 
@@ -163,6 +167,15 @@ void QgsAttributeTableModel::layerDeleted()
   beginRemoveRows( QModelIndex(), 0, rowCount() - 1 );
   removeRows( 0, rowCount() );
   endRemoveRows();
+
+  const QgsFields& fields = layer()->pendingFields();
+  for ( int idx = 0; idx < fields.count(); ++idx )
+  {
+    if ( layer()->editType( idx ) != QgsVectorLayer::ValueRelation )
+      continue;
+
+    delete mValueMaps.take( idx );
+  }
 }
 
 void QgsAttributeTableModel::attributeValueChanged( QgsFeatureId fid, int idx, const QVariant &value )
@@ -393,6 +406,9 @@ int QgsAttributeTableModel::columnCount( const QModelIndex &parent ) const
 
 QVariant QgsAttributeTableModel::headerData( int section, Qt::Orientation orientation, int role ) const
 {
+  if ( !layer() )
+    return QVariant();
+
   if ( role == Qt::DisplayRole )
   {
     if ( orientation == Qt::Vertical ) //row