title: Get a cumulative git diffs for multiple non-consecutuve commits
body: <p>I'd like to know if there's a way to get a cumulative git diff for multiple non-consecutive commits.</p>
  
  <p>For an example, I can get a what changed in each commit using:</p>
  
  <pre><code>git diff 123456^ 123456
  </code></pre>
  
  <p>Where "123456" is a git hash.</p>
  
  <p>I can go this for multiple commits. But I now I want to do multiple diffs and combine the output into one.</p>
  
  <p>For an example,</p>
  
  <pre><code>git diff 123456^ 123456
  git diff abcdef^ abcdef
  </code></pre>
  
  <p>But combine the diff into one. But "123456" and "abcdef" are not consecutive commits.</p>
  
  <p><strong>Update:</strong>
  Lets say a line in file xyz changed:</p>
  
  <pre><code>In commit 123456: from "foo" to "bar"
  in commit abcdef: from "bar" to "oof"
  </code></pre>
  
  <p>I just want to see that it changed from "foo" to "oof" after these to commits. </p>
  
  <p><em>git diff 123456 abcdef</em> does not work for me because I don't want to all the changes in between 123456 and abcdef.</p>
  
  <p>I dont want to commit anything; just want to this to review code for security.</p>