Avoid crash with invalid relation

m-kuhn · m-kuhn · commit 7fb3a4eb66cc · 2017-11-20T20:31:39.000+01:00
diff --git a/src/core/qgsaggregatecalculator.h b/src/core/qgsaggregatecalculator.h
@@ -46,7 +46,7 @@ class CORE_EXPORT QgsAggregateCalculator
     /**
      * Structured information about the available aggregates.
      *
-     * \since QGIS 3.0
+     * \since QGIS 3.2
      */
     struct AggregateInfo
     {
diff --git a/src/gui/editorwidgets/qgsrelationaggregatesearchwidgetwrapper.cpp b/src/gui/editorwidgets/qgsrelationaggregatesearchwidgetwrapper.cpp
@@ -30,7 +30,10 @@ QgsRelationAggregateSearchWidgetWrapper::QgsRelationAggregateSearchWidgetWrapper
 
 QString QgsRelationAggregateSearchWidgetWrapper::expression() const
 {
-  QString aggregateFilter = mAttributeForm->aggregateFilter();
+  QString aggregateFilter;
+
+  if ( mAttributeForm )
+    aggregateFilter = mAttributeForm->aggregateFilter();
 
   if ( aggregateFilter.isEmpty() )
     return QStringLiteral( "TRUE" );
@@ -45,10 +48,22 @@ bool QgsRelationAggregateSearchWidgetWrapper::valid() const
 
 QWidget *QgsRelationAggregateSearchWidgetWrapper::createWidget( QWidget *parent )
 {
-  QgsAttributeEditorContext subContext = QgsAttributeEditorContext( context(), mWrapper->relation(), QgsAttributeEditorContext::Multiple, QgsAttributeEditorContext::Embed );
-  mAttributeForm = new QgsAttributeForm( mWrapper->relation().referencingLayer(), QgsFeature(), subContext, parent );
-  mAttributeForm->setMode( QgsAttributeForm::AggregateSearchMode );
-  return mAttributeForm;
+  QWidget *widget;
+  QgsRelation relation = mWrapper->relation();
+
+  if ( !relation.isValid() )
+  {
+    widget = new QLabel( tr( "Relation not valid" ) );
+  }
+  else
+  {
+    QgsAttributeEditorContext subContext = QgsAttributeEditorContext( context(), mWrapper->relation(), QgsAttributeEditorContext::Multiple, QgsAttributeEditorContext::Embed );
+    mAttributeForm = new QgsAttributeForm( mWrapper->relation().referencingLayer(), QgsFeature(), subContext, parent );
+    mAttributeForm->setMode( QgsAttributeForm::AggregateSearchMode );
+    widget = mAttributeForm;
+  }
+
+  return widget;
 }
 
 bool QgsRelationAggregateSearchWidgetWrapper::applyDirectly()
diff --git a/src/gui/editorwidgets/qgsrelationaggregatesearchwidgetwrapper.h b/src/gui/editorwidgets/qgsrelationaggregatesearchwidgetwrapper.h
@@ -51,10 +51,8 @@ class GUI_EXPORT QgsRelationAggregateSearchWidgetWrapper : public QgsSearchWidge
     virtual void setExpression( const QString &value ) override;
 
   private:
-    QgsRelationWidgetWrapper *mWrapper;
-    QgsAttributeForm *mAttributeForm;
-
-
+    QgsRelationWidgetWrapper *mWrapper = nullptr;
+    QgsAttributeForm *mAttributeForm = nullptr;
 };
 
 #endif // QGSRELATIONAGGREGATESEARCHWIDGETWRAPPER_H

Original file line number	Diff line number	Diff line change
`@@ -46,7 +46,7 @@ class CORE_EXPORT QgsAggregateCalculator`
`46`	`46`	`/**`
`47`	`47`	`* Structured information about the available aggregates.`
`48`	`48`	`*`
`49`		`- * \since QGIS 3.0`
	`49`	`+ * \since QGIS 3.2`
`50`	`50`	`*/`
`51`	`51`	`struct AggregateInfo`
`52`	`52`	`{`