title: WIX, how to not replace config file
body: <p>We have a MSI built with wix that installs our ruby based product.  When we released the first version there was a bug.  Upgrades would overwrite changes to a ruby config file (gemrc), effectively breaking the product in some cases.</p>
  
  <p>I've been trying to get MSI to not remove or replace the config file on upgrades, without success.  </p>
  
  <p>What i have now is:</p>
  
  <pre><code>&lt;InstallExecuteSequence&gt;
    &lt;RemoveExistingProducts After="InstallExecuteAgain" /&gt;
  &lt;/InstallExecuteSequence&gt;
  
  
    &lt;Directory Id="embeddedDir" Name="embedded"&gt;
      &lt;Directory Id="embeddedEtcDir" Name="etc"&gt;
        &lt;Component Id="gemrcComponent" Guid="uuid..." NeverOverwrite='yes' Permanent='yes'&gt;
          &lt;File Id='gemrc' Name='gemrc'
                Source='$(var.ProjectSourceDir)\embedded\etc\gemrc.default' Vital='yes' KeyPath='yes' /&gt;
        &lt;/Component&gt;
      &lt;/Directory&gt;
  
    &lt;/Directory&gt;
  </code></pre>
  
  <p>However, going from the current version (1.0) to the new version (1.1) will leave the installation with no gemrc at all.  Going forward it works, so going from 1.1 to 1.2 it leaves the existing (modified) file. </p>
  
  <p>I'm assuming, that the reason it doesn't work is because it uses the old 1.0 MSI to remove the existing installation, and that version has the gemrc file marked as part of the product that needs to be removed.  </p>
  
  <p>This means the only way i could get around this is using custom actions (copy the file to a temp path before installation, and then move it back afterwards. 
   Or something similar).  Is there a better/easier way?   </p>