title: Git cherry pick creates duplicate commits
body: <p>After cherry-picking some commits from one branch to another branch, i still see commits when a pull request is created later.</p>
  
  <p>Say for example, There is a git project which has two branches : Dev , Release.</p>
  
  <p>And commit history is in following order.</p>
  
  <p>DEV : a1, a2, a3, a4, a5, a6</p>
  
  <p>RELEASE : a1, a2</p>
  
  <p>Now if i cherry-picked commits a3 and a5 alone from Dev to Release. Now the commit history will be as shown below. cherry-picked commits will have new SHA (b1 &amp; b2).</p>
  
  <p>RELEASE : a1, a2, b1, b2.</p>
  
  <p>Later if i try to create a pull request from Dev to Release branch, i stil see the commits a3 and a5.</p>
  
  <p>But in this case how can i find difference in commits between these two branches? </p>
  
  <p>I saw some articles stating 'rebase' but not able to understand the logic behind it.</p>