Don’t match selectors on empty blocks.
Don’t match selectors on empty blocks.

andrewleech/WeasyPrint,marclaporte/WeasyPrint,jasco/WeasyPrint,prepare/TestWeasyPrint,Kozea/WeasyPrint,Kozea/WeasyPrint,jasco/WeasyPrint,marclaporte/WeasyPrint,andrewleech/WeasyPrint,prepare/TestWeasyPrint