With the attached patch in the FieldEditor Context Menu is added additional feature of cleaning URL pasted from Google's search results.
Many persons find URL's of materials on web using Google search. If they want to copy/paste URL from search results in JabRef, they will paste "dirty" URL that is "enriched" with many Google's meta data.
E.g. Google's Copy link address function return this link: https://www.google.hr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=11&cad=rja&ved=0CDAQFjAAOAo&url=http%3A%2F%2Fwww.learnpunjabi.org%2Fpdf%2Fgslehal-pap18.pdf&ei=hzLRUcmHD8axtAavtYHwCA&usg=AFQjCNEnFN_fZSP8fxoGkUPMUHQW1IYpjg&sig2=auZxwSd57dp-qcJGli53Fg&bvm=bv.48572450,d.Yms
You can paste it in the JabRef's URL text field. After that, using this patch functionality this URL is cleaned and transformed in real URL: http://www.learnpunjabi.org/pdf/gslehal-pap18.pdf
The patch is tested in last beta JabRef version 2.10.