title: Correct way to compare same file in different branches
body: <p>This question <a href="https://stackoverflow.com/questions/4099742/how-can-i-compare-files-from-two-different-branches">How to compare files from two different branches?</a> deals with the issue of comparing the same file in different branches, but several answers are given and all of them appear to have some caveat.</p>
  
  <p>These are the ways presented:</p>
  
  <pre><code>1- git difftool mybranch master -- myfile.cs
  </code></pre>
  
  <p>(several people complain about this not working for them; it did in my case)</p>
  
  <pre><code>2- git difftool branch1:file branch2:file
  </code></pre>
  
  <p>(a comment says "<em>Using the colons is not really a great way</em>")</p>
  
  <pre><code>3- git difftool branch1 branch2 path/to/file
  </code></pre>
  
  <p>Which one is the recommended way?</p>