Traceback (most recent call last):
  File "/home/tomek/store/src/calibre/gui2/store/search/download_thread.py", line 119, in run
    for res in store_plugin.search(query, max_results=max_results, timeout=timeout):
  File "calibre_plugins.store_wolne_lektury.wolne_lektury", line 19, in search
  File "/home/tomek/store/src/calibre/gui2/store/opensearch_store.py", line 58, in search
    with closing(br.open(url, timeout=timeout)) as f:
  File "/usr/lib/python2.7/dist-packages/mechanize/_mechanize.py", line 203, in open
    return self._mech_open(url, data, timeout=timeout)
  File "/usr/lib/python2.7/dist-packages/mechanize/_mechanize.py", line 255, in _mech_open
    raise response
httperror_seek_wrapper: HTTP Error 500: INTERNAL SERVER ERROR

    def search(self, query, max_results=10, timeout=60):
        if not hasattr(self, 'open_search_url'):
            return

        description = Description(self.open_search_url)
        url_template = description.get_best_template()
        if not url_template:
            return
        oquery = Query(url_template)
               
        # set up initial values
        oquery.searchTerms = query
        oquery.count = max_results
        url = oquery.url()
               
        counter = max_results
        br = browser()
        with closing(br.open(url, timeout=timeout)) as f:

# -*- coding: utf-8 -*-

from __future__ import (unicode_literals, division, absolute_import, print_function)

__license__ = 'GPL 3'
__copyright__ = '2012, Tomasz Długosz <tomek3d@gmail.com>'
__docformat__ = 'restructuredtext en'

import re
import urllib
from contextlib import closing

from lxml import html

from PyQt4.Qt import QUrl

from calibre import browser, url_slash_cleaner
from calibre.gui2 import open_url
from calibre.gui2.store import StorePlugin
from calibre.gui2.store.basic_config import BasicStoreConfig
from calibre.gui2.store.search_result import SearchResult
from calibre.gui2.store.web_store_dialog import WebStoreDialog

class WolneLekturyStore(BasicStoreConfig, StorePlugin):

    def open(self, parent=None, detail_item=None, external=False):

        url = 'http://wolnelektury.pl'
        detail_url = None

        if detail_item:
            detail_url = detail_item

        if external or self.config.get('open_external', False):
            open_url(QUrl(url_slash_cleaner(detail_url if detail_url else url)))
        else:
            d = WebStoreDialog(self.gui, url, parent, detail_url)
            d.setWindowTitle(self.name)
            d.set_tags(self.config.get('tags', ''))
            d.exec_()

    def search(self, query, max_results=10, timeout=60):
        url = 'http://wolnelektury.pl/szukaj?q=' + urllib.quote_plus(query.encode('utf-8'))

        br = browser()

        counter = max_results
        with closing(br.open(url, timeout=timeout)) as f:
            doc = html.fromstring(f.read())
            for data in doc.xpath('//li[@class="Book-item"]'):
                if counter <= 0:
                    break

                id = ''.join(data.xpath('.//div[@class="title"]/a/@href'))
                if not id:
                    continue

                cover_url = ''.join(data.xpath('.//a[1]/img/@src'))
                title = ''.join(data.xpath('.//div[@class="title"]/a[1]/text()'))
                author = ', '.join(data.xpath('.//div[@class="mono author"]/a/text()'))
                price = '0,00 zł'
                formats = ', '.join(data.xpath('.//div[@class="book-box-formats mono"]/span/a/text()'))

                counter -= 1

                s = SearchResult()
                s.cover_url = 'http://wolnelektury.pl' + cover_url.strip()
                s.title = title.strip()
                s.author = author
                s.price = price
                s.detail_item = 'http://wolnelektury.pl' + id
                s.formats = formats.upper().strip()
                s.drm = SearchResult.DRM_UNLOCKED

                yield s