Created attachment 1005752 [details]
screeenshot 1

Description of problem:
When scheduling config file diffs from the webui, the diff-command finishes and confirms that differences do exist. When browsing to the diff result, no differences are show at all. This was broken and fixed earlier somewhere in the 1.9-2.2 timeframe and has worked for me in some former 2.3/nightly versions, but just stopped working recently again. 

Version-Release number of selected component (if applicable):
Client:
osad.noarch                                  5.11.56-1.el7
rhn-check.noarch                             2.3.16-1.el7
rhn-client-tools.noarch                      2.3.16-1.el7
rhn-setup.noarch                             2.3.16-1.el7
rhncfg.noarch                                5.10.83-1.el7
rhncfg-actions.noarch                        5.10.83-1.el7
rhncfg-client.noarch                         5.10.83-1.el7
rhnlib.noarch                                2.5.75-1.el7
rhnsd.x86_64                                 5.0.15-1.el7
spacewalk-backend-libs.noarch                2.3.51-1.el7


Spacewalk:
osa-dispatcher.noarch                        5.11.56-1.el7
osa-dispatcher-selinux.noarch                5.11.56-1.el7
rhn-check.noarch                             2.3.16-1.el7
rhn-client-tools.noarch                      2.3.16-1.el7
rhn-org-trusted-ssl-cert.noarch              1.0-2
rhn-setup.noarch                             2.3.16-1.el7
rhncfg.noarch                                5.10.83-1.el7
rhncfg-client.noarch                         5.10.83-1.el7
rhnlib.noarch                                2.5.75-1.el7
rhnpush.noarch                               5.5.88-1.el7
rhnsd.x86_64                                 5.0.15-1.el7
spacewalk-admin.noarch                       2.3.4-1.el7
spacewalk-backend.noarch                     2.3.51-1.el7
spacewalk-backend-app.noarch                 2.3.51-1.el7
spacewalk-backend-applet.noarch              2.3.51-1.el7
spacewalk-backend-config-files.noarch        2.3.51-1.el7
spacewalk-backend-config-files-common.noarch 2.3.51-1.el7
spacewalk-backend-config-files-tool.noarch   2.3.51-1.el7
spacewalk-backend-iss.noarch                 2.3.51-1.el7
spacewalk-backend-iss-export.noarch          2.3.51-1.el7
spacewalk-backend-libs.noarch                2.3.51-1.el7
spacewalk-backend-package-push-server.noarch 2.3.51-1.el7
spacewalk-backend-server.noarch              2.3.51-1.el7
spacewalk-backend-sql.noarch                 2.3.51-1.el7
spacewalk-backend-sql-postgresql.noarch      2.3.51-1.el7
spacewalk-backend-tools.noarch               2.3.51-1.el7
spacewalk-backend-xml-export-libs.noarch     2.3.51-1.el7
spacewalk-backend-xmlrpc.noarch              2.3.51-1.el7
spacewalk-base.noarch                        2.3.52-1.el7
spacewalk-base-minimal.noarch                2.3.52-1.el7
spacewalk-base-minimal-config.noarch         2.3.52-1.el7
spacewalk-branding.noarch                    2.3.25-1.el7
spacewalk-certs-tools.noarch                 2.3.2-1.el7
spacewalk-client-repo.noarch                 2.3-2.el7
spacewalk-common.noarch                      2.3.3-1.el7
spacewalk-config.noarch                      2.3.17-1.el7
spacewalk-doc-indexes.noarch                 2.3.3-1.el7
spacewalk-html.noarch                        2.3.52-1.el7
spacewalk-java.noarch                        2.3.172-1.el7
spacewalk-java-config.noarch                 2.3.172-1.el7
spacewalk-java-lib.noarch                    2.3.172-1.el7
spacewalk-java-postgresql.noarch             2.3.172-1.el7
spacewalk-jpp-workaround.noarch              2.3.2-1.el7
spacewalk-monitoring.noarch                  2.2.1-1.el7
spacewalk-monitoring-selinux.noarch          2.2.1-1.el7
spacewalk-postgresql.noarch                  2.3.3-1.el7
spacewalk-repo.noarch                        2.3-2.el7
spacewalk-schema.noarch                      2.3.40-1.el7
spacewalk-search.noarch                      2.3.6-1.el7
spacewalk-selinux.noarch                     2.3.2-1.el7
spacewalk-setup.noarch                       2.3.14-1.el7
spacewalk-setup-jabberd.noarch               2.3.2-1.el7
spacewalk-setup-postgresql.noarch            2.3.1-1.el7
spacewalk-taskomatic.noarch                  2.3.172-1.el7


How reproducible:
Always

Steps to Reproduce:
1. Schedule config file diff using the webui
2. Wait for the action to complete
3. Check result of the diff action

Actual results:
Diff action states that differences exit, but details fail to show any differences. rhncfg-client on the client shows the differences just fine.

Expected results:
Details of diff action show file differences again.

Additional info:
On the client rhncfg-client works as expected:

[user@client:~%] sudo rhncfg-client verify
[sudo] password for user: 
Using server name spacewalk.example.com
         modified /etc/NetworkManager/NetworkManager.conf
         modified /etc/aliases
         modified /etc/chrony.conf
         modified /etc/firewalld/services/zabbix-agent.xml
          missing /etc/firewalld/zones/internal.xml
         modified /etc/firewalld/zones/public.xml
         modified /etc/nsswitch.conf
         modified /etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
         modified /etc/pki/rpm-gpg/RPM-GPG-KEY-LOGsuite
          missing /etc/pki/rpm-gpg/RPM-GPG-KEY-SCM
         modified /etc/pki/rpm-gpg/RPM-GPG-KEY-jenkins
          missing /etc/pki/rpm-gpg/RPM-GPG-KEY-ovirt
         modified /etc/pki/rpm-gpg/RPM-GPG-KEY-spacewalk-2012
         modified /etc/resolv.conf
         modified /etc/rsyslog.conf
          missing /etc/setroubleshoot/setroubleshoot.conf
         modified /etc/ssh/banner
 selinux,modified /etc/ssh/sshd_config
         modified /etc/sssd/sssd.conf
             mode /etc/sysconfig/backup
         modified /etc/sysconfig/network
         modified /etc/sysconfig/rhn/rhncfg-client.conf
         modified /etc/watchdog.conf
                  /etc/zabbix/conf.d
         modified /etc/zabbix_agentd.conf
                  /usr/bin/backup_postdumpusercmd
                  /usr/bin/backup_postshareusercmd
                  /usr/bin/backup_predumpusercmd
                  /usr/bin/backup_preshareusercmd
         modified /usr/bin/generate_certificate
          missing /usr/bin/generate_keystore
                  /usr/lib/systemd/system/rhel-domainname.service
          missing /var/lib/setroubleshoot/email_alert_recipients

display_diff on the client is set:

[user@client:~%] grep -i display /etc/sysconfig/rhn/rhncfg-client.conf
# Should we display the diff of a file that is only readable by root? By
display_diff = True

No selinux AVCs are logged, on the client everything looks just fine.