QGIS » QGIS Application

If a layer has only one attribute, the default sub-clause for the _Control feature rendering order_ order-by-clause is added everytime

* the _Define order_ dialog is opened

* the last sub-clause in that dialog loses focus



Reproduce:

* Create a memory layer with a single attribute @Attr@

* Open the _Vector layer properties_ dialog

* Open the _Define order_ dialog

* -> Note the default clause _Attr ASC NULLS LAST_ is added automatically.

* Click to set the focus to the text-edit containing _Attr_

* Click anywhere else to take the focus away from it

* -> The default clause is added again.

* Close the dialog

* Re-open the dialog

* -> The default clause is added again.