In commit 04ba0e99, we introduced an optimization for reading inherited fields
in a single query. There is an issue when you have more than one level of
`_inherits`. The query looks like:
SELECT ...
FROM table0, table1 AS alias1, table2 AS alias2
WHERE table0.link0 = alias1.id AND table1.link1 = alias2.id AND ...
^^^^^^
should be alias1
This fixes the issue, and adds a test to reproduce it. The fix is based on
@emiprotechnologies's own proposal, but is cleaner and does not break APIs.