title: Rpm upgrade handling of config files
body: <p>I'm playing around with the rpm -upgrade command and noticed rpm has different ways of handling modified configuration files so it doesn't get lost during the upgrade. From what I understand, if a config file was modified and the package is upgraded with rpm -U, rpm will rename the original properties file as {file}.rpmsave and install the new configuration file with the original file name {file}. </p>
  
  <p>However, when I attempt to run rpm -U with the package I've created, what I actually see is the original configuration file gets deleted and the new configuration file gets renamed to {file}.rpmsave. Is this the intended behavior? In my install script I also modify some text in the configuration file with "sed". Could this have interfered with the way rpm handles configuration file during an upgrade?</p>