This new option, available under the "Advanced" button for fill symbols, allows forcing rendered polygons to follow the standard "right hand rule" for ring orientation (where exterior ring is clockwise, and interior rings are all counter-clockwise).
The orientation fix is applied while rendering only, and the original feature geometry is unchanged.
This allows for creation of fill symbols with consistent appearance, regardless of the dataset being rendered and the ring orientation of individual features.
This feature was funded by QGIS User Group Germany
This feature was developed by Nyall Dawson (North Road)