make ignoring a junk prefix 1.8.7 compatible
make ignoring a junk prefix 1.8.7 compatible

* see original 1.9 fix \#54
eitoball/pdf-reader,boutil/pdf-reader,tdenovan/pdf-reader,tardate/pdf-reader,yob/pdf-reader,gordonbisnor/pdf-reader,yob/pdf-reader,nifarius/pdf-reader,yob/pdf-reader,alexdowad/pdf-reader,nmadura/pdf-reader