prawnpdf/prawn — pull request #482 by aayushkhandelwal11 (2013-05-02 13:56:23+00:00)
Title: Checking graphic state exists for previous page before duping when starting new_page

Whenver pdf.start_new_page is called. The previous page graphic_state is duped without checking if graphic state exists for the previous page which result in can't dup nil class error