title: Unresolvable Git error: The following untracked working tree files would be overwritten by checkout
body: <p>I am using Git alone for my local software project in Visual Studio 2010. Recently I created a new branch to do a larger refactoring of one of the dialogue windows. I did the following modifications:</p>
  
  <ul>
  <li>Rename Form1 to Form1a (including all depending files)</li>
  <li>Add new Form1</li>
  </ul>
  
  <p>I checked this change into the branch, say form-refactoring. Interestingly, Git didn't notice that I renamed the file Form1.cs into Form1a.cs and created a brand new, totally different Form1.cs, but instead it noticed a new Form1a.cs file and found a whole lot of differences between the previous and new Form1.cs files. This will of course lead to totally garbaged diffs, but I don't care in this case as long as all files are handled correctly in the end.</p>
  
  <p>Then I switched back to master to do some other small changes. Nothing conflicting. Until now, everything worked fine.</p>
  
  <p>Today, I wanted to switch back to my branch form-refactoring to continue that work. But all I get is the following message:</p>
  
  <pre><code>git.exe checkout    form-refactoring
  
  Aborting
  error: The following untracked working tree files would be overwritten by checkout:
  Form1.Designer.cs
  Please move or remove them before you can switch branches.
  </code></pre>
  
  <p>What is that supposed to be? The mentioned file is not untracked. Neither in the master branch, nor in the form-refactoring branch. It is part of both branches, but one is not a descendent of the other. What would happen if I delete it, is it gone for good then? I don't trust Git to bring back the correct file if I delete something now. I did not play with any file at all outside of my mentioned Git operations, so why should I play around with any file to continue using Git operations now? Git broke it, Git's supposed to handle it now!</p>
  
  <p>Right now, I cannot continue with my work because I cannot switch branches. Is there an easy solution to this?</p>
  
  <p>Git version is 1.7.6, TortoiseGit is 1.7.3.</p>