title: Git - Need help understanding why commit is in history but does not show for file
body: <p>There is a particular commit hash that I am interested in:</p>
  
  <pre><code>git show 868cd84a941 --name-status
  </code></pre>
  
  <p>This command shows that the commit modified the file:</p>
  
  <pre><code>M       src/web/thirdParty/jquery/jquery.js
  </code></pre>
  
  <p>When I run the command: </p>
  
  <pre><code>git branch --contains 868cd84a941
  </code></pre>
  
  <p>One of the branch names returned is '2018_06'</p>
  
  <p>However, when I have the 2018_06 branch checked out, and I view the file history via the command:</p>
  
  <pre><code>git log --graph --oneline --decorate -- src/web/thirdParty/jquery/jquery.js
  </code></pre>
  
  <p>It only shows one line of history:</p>
  
  <pre><code>* a7ef0eab25f Add 'src/web/thirdParty/' from commit '5a733590a44a84cafb17afa8d8f7379a5ee2cd0e'
  </code></pre>
  
  <p>Which is not the commit I am interested in. Why do I not see this commit in this file's history if that commit was made or merged into this branch?</p>
  
  <p>Looking through the history it appears that, at some point, a commit was made that claims to have merged the branch containing the original commit into the main branch. However, it seems that this merge commit was made without actually merging any changes from the branch in.</p>