Description of problem:

The Gnome software updater throws the following stack trace in a popup window
at our site as soon as there are packages to update. The updates can be installed after clicking the message away:

Error Type: <type 'exceptions.AttributeError'>
Error Value: 'NoneType' object has no attribute 'find'
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 3587, in <module>
    main()
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 3584, in main
    backend.dispatcher(sys.argv[1:])
  File : /usr/lib64/python2.7/site-packages/packagekit/backend.py, line 721, in dispatcher
    self.dispatch_command(args[0], args[1:])
  File : /usr/lib64/python2.7/site-packages/packagekit/backend.py, line 603, in dispatch_command
    self.get_update_detail(package_ids)
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 2953, in get_update_detail
    desc, urls, reboot, changelog, state, issued, updated = self._get_update_extras(pkg)
  File : /usr/share/PackageKit/helpers/yum/yumBackend.py, line 2885, in _get_update_extras
    if notice['from'].find('updates') != -1:

Version-Release number of selected component (if applicable):

PackageKit-yum-0.8.9-11.el7.x86_64

How reproducible:

Always.

Steps to Reproduce:
1. Start the Software Update application when updates are available.

Additional info:

The problem seems to stem from this ancient patch:

  https://bugs.freedesktop.org/attachment.cgi?id=37813&action=edit

In the second replaced line the code should first check if "if notice['from']" is defined. Sloppy programming...