Three middleware answer before HandleInertiaRequests and so have to
repeat its 302→303 upgrade themselves: EnsureSetupIsComplete,
EnsureUserIsActive and EnforceTwoFactor. This file has a write case for
each, and the rule has a second half -- a read still gets a plain 302,
because a 303 there would be an upgrade nobody asked for.
That half was checked once, on the deactivation door, under a name that
said otherwise: "leaves a read alone in every one of those cases". The
setup door and the two-factor door were not covered at all, so a change
that upgraded reads at either of them would have gone through with the
suite green and this test's name still claiming it would not.
Both are covered now, as a dataset with one case per door. The setup case
reads a guest-reachable GET for the same reason the write case posts to
/timezone: anything behind `auth` is answered by the guest redirect before
EnsureSetupIsComplete sees it.
No production code changes; today all three doors answer a read with 302,
which is what the new cases assert. Demonstrated by mutation rather than
reversion: making EnsureSetupIsComplete upgrade every redirect to 303
fails this file (1 failed / 8 passed) and passes the old one (7 passed).
#1680 fixed the redirect rendered from an exception and said plainly
what it did not cover: EnsureSetupIsComplete, EnsureAccountIsActive and
EnforceTwoFactor answer before HandleInertiaRequests is ever entered, so
a response they return never unwinds through Inertia's 302 to 303
upgrade either. Same 405, reached a different way — an account
deactivated while its owner was part-way through a form, or one being
made to enrol in two-factor.
The rule now lives in one place rather than four. Three copies of "if
the method is PUT, PATCH or DELETE" is how the fourth caller gets it
wrong, and WriteSafeRedirect can carry the explanation of why 303 —
which is worth more than the three lines it replaces, because nothing
about a bare setStatusCode call says what a browser does with a 302.
PUT /timezone is the route the setup test uses: it is one of only two
writes a guest can reach and the only one that middleware does not
exempt, so the case is real rather than defensive. All three new tests
were run against the unfixed middleware and fail there.
Extends the work of @denkfabrik-li, who found the gap and wrote it down.
A redirect born in exception handling - the guest redirect after an
expired login, above all - never travels back through the middleware
stack, so Inertia's usual 302-to-303 upgrade cannot reach it. Browsers
follow a 302 by replaying the request method on the redirect target
(only POST is downgraded to GET), so a widget save whose session just
died replays as PUT /login and fails with a 405 that hides the real
"please sign in again" (#1673).
Repeat the upgrade in the exception pipeline: any 302 answered to a
PUT, PATCH or DELETE becomes a 303. Reads keep their 302, POST needs
nothing - browsers already downgrade it.
denkfabrik-li