Steps to reproduce

1. Download the httpd.zip file.
2. Unzip it
3. Run in the unzipped directory:

   $ docker build -t httpd-proxyenabled .
   
   $ docker container run \                                    
   --publish 90:80 \
   -d --name apacheserver \
   httpd-proxyenabled
   

4. First command will build the image and second will start the apache httpd proxy and will forward it to the port 90 to the host machine.
5. Edit /etc/hosts and add 127.0.0.1    example.com
6. Start up Magnolia DX Core
7. Open admincentral at http://example.com:90/magnoliaAuthor
8. Publish /travel few times
9. Compare versions in the Pages app

Expected results

The Diff module shows changes between versions

Actual results

An empty screen is shown with apache httpd error.

Workaround

N/A

Development notes

The VersionDiffHtmlServlet.java forces the html ending (hardcoded), it should be taken dynamically from config (e.g, from defaultExtension attribute)

private String getSourceUrl(HttpServletRequest request, String contentHandle) {
    String baseUrl = StringUtils.substringBefore(request.getRequestURL().toString(), SERVICE_PATH);
    return baseUrl + contentHandle + ".html";
 }