Add error instead of assertion in corner case
Add error instead of assertion in corner case

mic4ael/indico,indico/indico,DirkHoffmann/indico,mic4ael/indico,OmeGak/indico,ThiefMaster/indico,ThiefMaster/indico,OmeGak/indico,ThiefMaster/indico,mic4ael/indico,mvidalgarcia/indico,ThiefMaster/indico,mvidalgarcia/indico,mic4ael/indico,DirkHoffmann/indico,DirkHoffmann/indico,pferreir/indico,indico/indico,pferreir/indico,mvidalgarcia/indico,DirkHoffmann/indico,pferreir/indico,mvidalgarcia/indico,OmeGak/indico,indico/indico,indico/indico,pferreir/indico,OmeGak/indico