Fixed #36704 -- Fixed system check error for proxy model with a composite pk.

Proxy models subclassing a model with a CompositePrimaryKey were
incorrectly reporting check errors because the check that requires only
local fields to be used in a composite pk was evaluated against the proxy
subclass, which has no fields.

To fix this, composite pk field checks are not evaluated against
proxy subclasses, as none of the checks are applicable to proxy
subclasses. This also has the benefit of not double-reporting real check
errors from an invalid superclass pk.

Thanks Clifford Gama for the review.

0 files changed, 0 insertions, 0 deletions