Fix crash while styling the title bar of a QMdiArea with stylesheet
Fix crash while styling the title bar of a QMdiArea with stylesheet

This stylesheet used to crash:  *::title { border 1px solid black }

Reviewed-by: bnilsen

RLovelett/qt,RLovelett/qt,radekp/qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,RLovelett/qt,igor-sfdc/qt-wk,RLovelett/qt,RLovelett/qt,KDE/qt,pruiz/wkhtmltopdf-qt,radekp/qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,RLovelett/qt,KDE/qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,KDE/qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,RLovelett/qt,radekp/qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,KDE/qt,radekp/qt,igor-sfdc/qt-wk,radekp/qt,KDE/qt,radekp/qt,KDE/qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,RLovelett/qt,RLovelett/qt,radekp/qt,RLovelett/qt,radekp/qt,KDE/qt,RLovelett/qt,radekp/qt,pruiz/wkhtmltopdf-qt,KDE/qt,radekp/qt