The save-time simulation read the rules at READ COMMITTED without a lock,
so A -> B and B -> A written concurrently both passed. CheckRedirect,
AddressChanged and every batch now take a transaction-level advisory lock
before they read the rules.
AddressChanged wrote its 301 and re-pointed rules without Problems or the
save-time simulation, and removed only an exact rule whose source equals
the new address literally. It now removes every exact rule that matches
the new address with its options, simulates the 301 and the re-pointing
with the stored rules and writes nothing when that loops, stores an
absolute old address on the site as its path, and skips an address that
is not a path on the site.
- golem15_seo_redirects table and Redirect model
- AddressChanged: old -> new 301 in the save transaction, earlier
redirects pointed at the new address, self-loops dropped
- the SEO tab save compares descriptor URLs with the entry URLs and
answers the redirects.auto_created notice
- resolve answers redirect with the absolute target for an exact source
