links with occur searches do not use regular expressions

[C7DAFBB7]

I don't know if this is a bug or not. It seems so straight-forward that I can easily be convinced that it is intentional or that I've missed something in the docs. Links with occur strings do not search for regular expressions. The reason is that the call to pdf-occur-search does not have a non-nil third argument. As far as I can see changing the call from

         (pdf-occur-search
          pathlist
          occur-search-string)))

to

         (pdf-occur-search
          pathlist
          occur-search-string t)))

fixes the problem.