QuickDesigner: Negative font spacing display issue

Steps to reproduce:

• create a Qt Quick Application from template (I've used Swipe)
• add some Qt Quick Controls using the designer on one of the ui.qml files
• set a negative spacing for one of the controls that have font settings

Current result:

• the minus sign is not visible (due to width of the control)

Expected result:

• either make the control wider to make negative sign visible
• or handle it with colours? (red for negative?)