bug fix for issue #104

[tataganesh]

Sometimes, when the _load_data function is called in cmapdb.py, the following error is invoked -

File "/home/ganesh/.virtualenvs/cv/local/lib/python2.7/site-packages/pdfminer/pdfinterp.py", line 832, in process_page
    self.render_contents(page.resources, page.contents, ctm=ctm)
  File "/home/ganesh/.virtualenvs/cv/local/lib/python2.7/site-packages/pdfminer/pdfinterp.py", line 843, in render_contents
    self.init_resources(resources)
  File "/home/ganesh/.virtualenvs/cv/local/lib/python2.7/site-packages/pdfminer/pdfinterp.py", line 347, in init_resources
    self.fontmap[fontid] = self.rsrcmgr.get_font(objid, spec)
  File "/home/ganesh/.virtualenvs/cv/local/lib/python2.7/site-packages/pdfminer/pdfinterp.py", line 195, in get_font
    font = self.get_font(None, subspec)
  File "/home/ganesh/.virtualenvs/cv/local/lib/python2.7/site-packages/pdfminer/pdfinterp.py", line 186, in get_font
    font = PDFCIDFont(self, spec)
  File "/home/ganesh/.virtualenvs/cv/local/lib/python2.7/site-packages/pdfminer/pdffont.py", line 668, in __init__
    self.unicode_map = CMapDB.get_unicode_map(self.cidcoding, self.cmap.is_vertical())
  File "/home/ganesh/.virtualenvs/cv/local/lib/python2.7/site-packages/pdfminer/cmapdb.py", line 283, in get_unicode_map
    data = klass._load_data('to-unicode-%s' % name)
  File "/home/ganesh/.virtualenvs/cv/local/lib/python2.7/site-packages/pdfminer/cmapdb.py", line 253, in _load_data
    if os.path.exists(path):
  File "/home/ganesh/.virtualenvs/cv/lib/python2.7/genericpath.py", line 26, in exists
    os.stat(path)
TypeError: stat() argument 1 must be encoded string without null bytes, not str

The snippet in question -

    def _load_data(klass, name):
        filename = '%s.pickle.gz' % name
        logging.info('loading: %r' % name)
        cmap_paths = (os.environ.get('CMAP_PATH', '/usr/share/pdfminer/'),
                      os.path.join(os.path.dirname(__file__), 'cmap'),)
        for directory in cmap_paths:
            path = os.path.join(directory, filename)
            if os.path.exists(path):

Printing the variable name gives me -
to-unicode-PDFXC30-Identity
Printing repr(name) gives me -
to-unicode-PDFXC30-Identity\x00\x00
Apparently, these \x00 characters are causing the issue. One fix that solved this issue for me was -
name = name.replace('\0', '')