Don't crash when project has no layers

This only crashes when Qt is built in debug mode because there is an assert in the item model class that checks for index range validity.
qgis · Dec 1, 2017 · 31c79da · 31c79da
1 parent 19b062c
commit 31c79da
Showing 1 changed file with 12 additions and 9 deletions.
diff --git a/src/core/qgsmaplayermodel.cpp b/src/core/qgsmaplayermodel.cpp
@@ -154,17 +154,20 @@ void QgsMapLayerModel::removeLayers( const QStringList &layerIds )
 
 void QgsMapLayerModel::addLayers( const QList<QgsMapLayer *> &layers )
 {
-  int offset = 0;
-  if ( mAllowEmpty )
-    offset++;
-
-  beginInsertRows( QModelIndex(), mLayers.count() + offset, mLayers.count() + layers.count() - 1  + offset );
-  Q_FOREACH ( QgsMapLayer *layer, layers )
+  if ( layers.count( ) )
   {
-    mLayers.append( layer );
-    mLayersChecked.insert( layer->id(), Qt::Unchecked );
+    int offset = 0;
+    if ( mAllowEmpty )
+      offset++;
+
+    beginInsertRows( QModelIndex(), mLayers.count() + offset, mLayers.count() + layers.count() - 1  + offset );
+    Q_FOREACH ( QgsMapLayer *layer, layers )
+    {
+      mLayers.append( layer );
+      mLayersChecked.insert( layer->id(), Qt::Unchecked );
+    }
+    endInsertRows();
   }
-  endInsertRows();
 }
 
 QModelIndex QgsMapLayerModel::index( int row, int column, const QModelIndex &parent ) const