title: Whoosh - accessing search_page result items throws ReaderClosed exception
body: <p>Following is a simple pagination function.</p>
  
  <pre><code>from whoosh import index
  def _search(q):
      wix = index.open_dir(settings.WHOOSH_INDEX_DIR)
      term = Term("title", q) | Term("content", q)
      page_id = 1
  
      with wix.searcher() as s:
          return s.search_page(term, page_id, pagelen=settings.ITEMS_PER_PAGE)
  
  In [15]: p = _search("like")
  
  In [16]: p.results[0].reader.is_closed
  Out[16]: True
  </code></pre>
  
  <p>if I try to access an attribute of a Hit, i get ReaderClosed exception.</p>
  
  <pre><code>In [19]: p.results
  Out[19]: &lt;Top 10 Results for Or([Term('title', 'like'), Term('content', 'like')]) runtime=0.0214910507202&gt;
  
  [21]: p.results[0]["title"]
  ---------------------------------------------------------------------------
  ReaderClosed                              Traceback (most recent call last)
  /usr/local/lib/python2.7/dist-packages/Django-1.5.3-py2.7.egg/django/core/management/commands/shell.p yc in &lt;module&gt;()
  ----&gt; 1 p.results[0]["title"]
  
  /usr/local/lib/python2.7/dist-packages/whoosh/searching.pyc in __getitem__(self, fieldname)
  1500 
  1501     def __getitem__(self, fieldname):
  -&gt; 1502         if fieldname in self.fields():
  1503             return self._fields[fieldname]
  1504 
  
  /usr/local/lib/python2.7/dist-packages/whoosh/searching.pyc in fields(self)
  1388 
  1389         if self._fields is None:
  -&gt; 1390             self._fields = self.searcher.stored_fields(self.docnum)
  1391         return self._fields
  1392 
  
  /usr/local/lib/python2.7/dist-packages/whoosh/reading.pyc in stored_fields(self, docnum)
  1197     def stored_fields(self, docnum):
  1198         segmentnum, segmentdoc = self._segment_and_docnum(docnum)
  -&gt; 1199         return self.readers[segmentnum].stored_fields(segmentdoc)
  1200 
  1201     # Per doc methods
  
  /usr/local/lib/python2.7/dist-packages/whoosh/reading.pyc in stored_fields(self, docnum)
      693     def stored_fields(self, docnum):
      694         if self.is_closed:
  --&gt; 695             raise ReaderClosed
      696         assert docnum &gt;= 0
      697         schema = self.schema
  
  ReaderClosed: 
  </code></pre>
  
  <p>How can i access hit's attributes?</p>