title: Why does GIT ignore tmp folders?
body: <p>Just noticed (after 4 years) that git seems to automatically ignore any tmp folder in any subdirectory of my project. Now, I'm quite happy with that but it worries me: are there other things it's ignoring by default?</p>
  <p>My .gitignore does have a line like:</p>
  <pre><code>tmp/
  </code></pre>
  <p>However if I remove that entry all my tmp folders are still ignored.</p>
  <p>There are no other mentions of 'tmp' in my .gitignore
  I've looked in other files e.g. '.git/info/exclude' and '.git/config' but can't see anything there.
  I've also looked at:</p>
  <pre><code>git config --get core.excludesfile
  </code></pre>
  <p>It returns nothing.</p>