title: fuzzyfinder: Error detected while processing function <SNR>19_onCommandPre
body: <p>When typing an command, I get an error like this:</p>
  
  <pre><code>:w
  Error detected while processing function &lt;SNR&gt;19_onCommandPre..fuf#mrucmd#onCommandPre..&lt;SNR&gt;25_updateInfo..fuf#updateMruList:
  line    2:
  E121: Undefined variable: word
  line    5:
  E121: Undefined variable: word
  </code></pre>
  
  <p>Is it a bug or just cause by my incorrect configuration?</p>
  
  <p>I set <code>let g:fuf_modesDisable=[]</code> in my .vimrc.</p>
  
  <p>And the vim version I use if vim 7.3, the fuzzyfinder version is fuzzyfinder 4.2.2</p>