title: CTRL-K in Vim produces unexpected results
body: <p>Hi I'm trying to optimise my window management in vim by mapping <kbd>ctrl</kbd><kbd>k</kbd> to <kbd>ctrl</kbd>+<kbd>w</kbd>, k so i can just press <kbd>ctrl</kbd>+<kbd>k</kbd> to switch to the split window above the one I'm working in (I'm doing this for h,j and l also but it's only k that's causing the problem).</p>
  
  <p>I've added this into my .vimrc</p>
  
  <pre><code>noremap &lt;silent&gt; &lt;c-k&gt; &lt;C-W&gt;k                                                                                                                
  noremap &lt;silent&gt; &lt;c-j&gt; &lt;C-W&gt;j                                                                                                      
  noremap &lt;silent&gt; &lt;c-h&gt; &lt;C-W&gt;h                                                                                                      
  noremap &lt;silent&gt; &lt;c-l&gt; &lt;C-W&gt;l
  </code></pre>
  
  <p>However if I press <kbd>ctrl</kbd>+<kbd>k</kbd>, then something weird happens. It changes depending on where I am in the document.</p>
  
  <ul>
  <li>If I'm at the top of a document with many lines beneath my curser, the cursor hops down a few lines and columns into a completely different place.</li>
  <li>If I'm at the bottom of a document, it creates loads of spaces from the cursor onwards.</li>
  </ul>
  
  <p>I've tested and removing the above lines causes the symptoms to stop happening. I'm just really confused as to what is going on!</p>
  
  <p>Some info: I'm using the vim binary that comes with macvim via the command line.</p>
  
  <p>Any help would be greatly appreciated!</p>
  
  <p>Thanks!</p>