Add safety check to avoid crash

qgis · Oct 1, 2016 · 9c11814 · 9c11814
1 parent 4a7a8ff
commit 9c11814
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/src/core/qgsexpression.cpp b/src/core/qgsexpression.cpp
@@ -3826,6 +3826,9 @@ QStringList QgsExpression::referencedColumns() const
 
 QSet<int> QgsExpression::referencedAttributeIndexes( const QgsFields& fields ) const
 {
+  if ( !d->mRootNode )
+    return QSet<int>();
+
   QStringList referencedFields = d->mRootNode->referencedColumns();
   QSet<int> referencedIndexes;