Merge pull request #6930 from m-kuhn/fixSearchCrash

Fix crash with uninitialized search widget

Author: m-kuhn

src/gui/qgsattributeformrelationeditorwidget.cpp

@@ -39,5 +39,9 @@ void QgsAttributeFormRelationEditorWidget::createSearchWidgetWrappers( const Qgs
 
 QString QgsAttributeFormRelationEditorWidget::currentFilterExpression() const
 {
-  return mSearchWidget->expression();
+  QString filterExpression;
+  if ( mSearchWidget )
+    filterExpression = mSearchWidget->expression();
+
+  return filterExpression;
 }