Re-add NULL in "Field and Values" expression

elpaso · nyalldawson · commit dc7f72997c14 · 2020-06-11T05:29:36.000+10:00
Fixes #37099
diff --git a/src/gui/qgsexpressiontreeview.cpp b/src/gui/qgsexpressiontreeview.cpp
@@ -426,10 +426,14 @@ void QgsExpressionTreeView::loadFieldNames( const QgsFields &fields )
 
 void QgsExpressionTreeView::loadFieldNames()
 {
+  // Cleanup
   if ( mExpressionGroups.contains( QStringLiteral( "Fields and Values" ) ) )
   {
     QgsExpressionItem *node = mExpressionGroups.value( QStringLiteral( "Fields and Values" ) );
     node->removeRows( 0, node->rowCount() );
+    // Re-add NULL
+    // use -1 as sort order here -- NULL should always show before the field list
+    registerItem( QStringLiteral( "Fields and Values" ), QStringLiteral( "NULL" ), QStringLiteral( "NULL" ), QString(), QgsExpressionItem::ExpressionNode, false, -1 );
   }
 
   // this can happen if fields are manually set

Original file line number	Diff line number	Diff line change
`@@ -426,10 +426,14 @@ void QgsExpressionTreeView::loadFieldNames( const QgsFields &fields )`
`426`	`426`
`427`	`427`	`void QgsExpressionTreeView::loadFieldNames()`
`428`	`428`	`{`
	`429`	`+ // Cleanup`
`429`	`430`	`if ( mExpressionGroups.contains( QStringLiteral( "Fields and Values" ) ) )`
`430`	`431`	`{`
`431`	`432`	`QgsExpressionItem *node = mExpressionGroups.value( QStringLiteral( "Fields and Values" ) );`
`432`	`433`	`node->removeRows( 0, node->rowCount() );`
	`434`	`+ // Re-add NULL`
	`435`	`+ // use -1 as sort order here -- NULL should always show before the field list`
	`436`	`+ registerItem( QStringLiteral( "Fields and Values" ), QStringLiteral( "NULL" ), QStringLiteral( "NULL" ), QString(), QgsExpressionItem::ExpressionNode, false, -1 );`
`433`	`437`	`}`
`434`	`438`
`435`	`439`	`// this can happen if fields are manually set`