title: Excluding certain files while 'git pull'
body: <p>I am doing a complex PHP project with two other people. We had git setup for the project from the beginning.  After working for two months, we wanted to remove certain folders (<code>/dev/app</code>) from git tracking ( git was already tracking them). So I deleted all the files from <code>/dev/app</code> and added a entry in the <code>.gitignore</code> file to exclude the <code>PHP</code> files in the <code>/dev/app</code> folder. </p>
  
  <pre><code>**/dev/app/*.php
  </code></pre>
  
  <p>I made a commit to the master branch. I pushed them to the origin and it was working fine. But my colleagues were working on different branches. When I merged their branches with the master, git started to track the excluded files again. </p>
  
  <p>In the local environment it is not a problem, but in the production environment it is a huge headache.  I only need the client generated files in the /dev/app folder in the production server, and I need to preserve them without any modification. </p>
  
  <p>can anyone help me to overcome the issue? </p>