The admin pages save the whole policy from the draft they loaded. A
save from a page opened before another tab's or another admin's save,
or before a deleted plugin was dropped from the policy, used to put the
older policy back. GET /api/admin/policy now sends the policy version as
an ETag; the policy, organisation, plugins and themes pages send it back
as If-Match, and a save based on an older version answers 409 and keeps
the draft on the page. A PUT without If-Match replaces the policy as
before. Deleting a plugin or theme changes only its id in the stored
policy, and a policy import compares against what it replaces.
Test mocks of the config manager gain getPolicyVersion and updatePolicy,
which the route and the extension cleanup now call.
Linus Rath
25408b2ac2