title: How do you apply a patch to ruby on rails?
body: <p>I'd like to apply the action_mailer patch mentioned in this thread but I have never applied a patch before and I'm not sure how these work:
  <a href="https://rails.lighthouseapp.com/projects/8994/tickets/2263" rel="noreferrer">https://rails.lighthouseapp.com/projects/8994/tickets/2263</a></p>
  
  <p>My action mailer gem is here: /opt/ruby-enterprise-1.8.6-20090421/lib/ruby/gems/1.8/gems/actionmailer-2.3.2</p>
  
  <p>I assume I need to go to that directory and run the patch command...something like this?</p>
  
  <pre><code>cd /opt/ruby-enterprise-1.8.6-20090421/lib/ruby/gems/1.8/gems/
  wget https://rails.lighthouseapp.com/attachments/108548/0001-Fix-implicit-multipart-mailer-views-when-RAILS_ROOT.patch
  patch &lt; 0001-Fix-implicit-multipart-mailer-views-when-RAILS_ROOT.patch
  </code></pre>
  
  <p>One thing I'm not really clear on also is that the patch file refers to the "actionmailer" directory but mine is called "actionmailer-2.3.2"</p>