Description of problem:
Incremental update with this errata ends with the following:
 - # hammer content-view version incremental-update --content-view-version-id='24' --errata-ids='RHSA-2018:0549' --resolve-dependencies='no' --update-all-hosts='no' --propagate-all-composites='yes'
...
  Errata:
        RHSA-2018:0549
  Packages:
        firefox-52.7.2-1.el6_9.x86_64
        libgcc-4.4.7-18.el6_9.2.x86_64
        libstdc++-4.4.7-18.el6_9.2.x86_64

When only Firefox is included in the errata itself.


How reproducible:
100%

This seems to be related to (caused by?) https://pulp.plan.io/issues/2478 more than anything else.

More info:
Errata entry in psql seems to have expected output and associations:
foreman=# select * from katello_erratum_packages where erratum_id = 20577;
   id   | erratum_id |             nvrea             |  name   |             filename              
--------+------------+-------------------------------+---------+-----------------------------------
 166272 |      20577 | firefox-52.7.2-1.el6_9.x86_64 | firefox | firefox-52.7.2-1.el6_9.x86_64.rpm
 166269 |      20577 | firefox-52.7.2-1.el7_4.i686   | firefox | firefox-52.7.2-1.el7_4.i686.rpm
 166104 |      20577 | firefox-52.7.2-1.el7_4.x86_64 | firefox | firefox-52.7.2-1.el7_4.x86_64.rpm
(3 rows)