Prefetch links that 404 should fall back to the network

[swyxio]

Describe the bug

i had a bug reported here: https://twitter.com/clearhunch/status/1494317555275677696?s=21

that essentially came from me using a prefetch link (<a svelte:prefetch href=“/LIP”>) for a url that only exists as a serverside redirect (in netlify). in a normal a href context that would work. but sveltekit is being too smart, or not smart enough, here. it checks its cache for a page called “LIP”, and not finding it, returns a 404 and end of story. i think it should deopt from clientside navigation and go actually check the network, and let the 404 handling happen there (again via sveltekit).

see what i mean? basically the only reason we do clientside nav is to make it fast, but we dont have to be fast for 404’s.

Reproduction

the diff i made swyxio/swyxdotio@4f16ef6

its really obvious but it is an abstraction leak, and yes i know i could just remove prefetch but why make me check

Logs

No response

System Info

n/a

Severity

annoyance

Additional Information

No response

[geoffrich]

This sounds related to #3935, though that issue doesn't call out prefetch specifically.

[Rich-Harris]

Just merged and released #3969 — does that solve this issue @sw-yx?

Aside: if you implemented the server-side redirect as a load function instead you could avoid the roundtrip:

<!-- src/routes/LIP.svelte -->
<script>
  export function load() {
    return {
      status: 308,
      redirect: '/learn-in-public
    };
  }
</script>

[swyxio]

i think it does, will close for now as something else broke in swyxkit when i updated deps so i am debugging multiple things at once

thank you