Converting "linked images" zones to non-linked

A while ago we introduced "nlipkg" zone brand in OI to create "non-linked" images. OmniOS uses ipkg as non-linked brand by default and has additional "lipkg" brand for linked images. Briefly speaking, when you deal with linked images, global zone's IPS knows a lot about zones, can work with them (for example, you can update all zones in one step with "pkg update -r") and imposes some restrictions on child images. Zone's brand is recorded in /etc/zones/zonename.xml and can be changed manually or using zonecfg. As ipkg and nlipkg zones are rather similar (in fact, they are distinguished only in name and IPS checks in some places on which brand it's operating, but for these two brands zone brand scripts are the same). So, when you are bugged with IPS checks for linked images, you can try to change zone's brand from ipkg to nlipkg. This even can work. The only issue is that it doesn't always work. Sometimes you still receive irritating messages like

pkg install: Invalid child image publisher configuration.  Child image publisher
configuration must be a superset of the parent image publisher configuration.
Please update the child publisher configuration to match the parent.  If the
child image is a zone this can be done automatically by detaching and
attaching the zone.

The parent image has the following enabled publishers:
    PUBLISHER 0: openindiana.org (non-sticky)
    PUBLISHER 1: userland (non-sticky)
    PUBLISHER 2: hipster-encumbered

The child image has the following enabled publishers:
    PUBLISHER 0: openindiana.org (non-sticky)
    PUBLISHER 1: hipster-encumbered

Even for nlipkg-branded zones. The issue is that inside zone IPS knows nothing about zone's brand. Its logic is always the same. The only thing which it checks for are files in /var/pkg/linked directory. These files are usually created on pkg operations initiated from GZ (the same pkg update -r) and contain information about parent image (read - GZ). When you change zone's brand, they will not disappear, and IPS inside zone will still think that it works with linked image. Luckily, to convince it that it's not true, it's enough to do "rm -fr /var/pkg/linked". Then this condition will make IPS happy. So, long story short - don't forget to remove /var/pkg/linked if you convert zone from ipkg to nlipkg brand.