title: Git: can't undo local changes (error: path ... is unmerged)
body: <p>I have following working tree state</p>
  
  <pre><code>$ git status foo/bar.txt
  # On branch master
  # Unmerged paths:
  #   (use "git reset HEAD &lt;file&gt;..." to unstage)
  #   (use "git add/rm &lt;file&gt;..." as appropriate to mark resolution)
  #
  #       deleted by us:      foo/bar.txt
  #
  no changes added to commit (use "git add" and/or "git commit -a")
  </code></pre>
  
  <p>File <code>foo/bar.txt</code> is there and I want to get it to the "unchanged state" again (similar to 'svn revert'):</p>
  
  <pre><code>$ git checkout HEAD foo/bar.txt
  error: path 'foo/bar.txt' is unmerged
  $ git reset HEAD foo/bar.txt
  Unstaged changes after reset:
  M       foo/bar.txt
  </code></pre>
  
  <p>Now it is getting confusing:</p>
  
  <pre><code>$ git status foo/bar.txt
  # On branch master
  # Changes to be committed:
  #   (use "git reset HEAD &lt;file&gt;..." to unstage)
  #
  #       new file:   foo/bar.txt
  #
  # Changed but not updated:
  #   (use "git add &lt;file&gt;..." to update what will be committed)
  #   (use "git checkout -- &lt;file&gt;..." to discard changes in working directory)
  #
  #       modified:   foo/bar.txt
  #
  </code></pre>
  
  <p>The same file in both sections, new <em>and</em> modified? What should I do?</p>