Prevented crash when parsing viewBox attribute value
Prevented crash when parsing viewBox attribute value

The old code assumed viewBox value of the form "x y w h" or "x,y,w,h",
and would crash when parsing "x,y w,h" (when accessing the fourth list
item which would be out-of-bounds).

Reviewed-by: Trond
Reviewed-by: Kim

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