Reported: go to an edit page, then press Home — nothing happens; navigation stops updating.
Root cause (found via a browser trace): a guarded route (host/require-login) answered a
BOOSTED (SX-Request) request with a 303 to /login. The browser's fetch follows the redirect
but DROPS the SX-Request header on the way, so /login returned the full HTML shell (<!doctype
html>…), not a text/sx fragment. Morphing that whole document into #content DESTROYS the
#content swap target (diagnostic: "#content count: 0"), so every later boosted nav fetches
but has nowhere to swap ("post-swap: root=nil") — the persistent nav Home appears to do
nothing.
Fix (host-side, no engine change — the engine already supports SX-Redirect): for a boosted
request require-login now returns 200 + an `SX-Redirect: /login?next=…` header. The engine
does a FULL navigation (browser-navigate) to a real /login page — #content is never
clobbered. Non-boosted requests still get a plain 303. Also added a "← Home" link to the
login shell (it's a standalone page with no persistent nav, so a logged-out user who followed
a guarded link was otherwise stranded — the literal "press Home" case).
TEST-FIRST: added a second boost-nav.spec.js case (home → post → click edit → assert clean
full-nav to /login, NOT a clobbered SPA, and Home works from there). Confirmed RED before
(Home did nothing on the clobbered page), GREEN after — verified on the ephemeral server AND
live. No regressions: picker 3/3 + block-editor 1/1 (login flow intact).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
giles
88f8b427c5