Infinite loop when accessing prerendered +server.js from matching non-prerendered +server.js

[dummdidumm]

Describe the bug

Given this structure

[id].json/+server
examples.json/+server

with examples.json being prerendered and [id].json fetching examples.json, the server is fine at dev time but crashes in prod. The manifest seems to not properly resolve the correct route, instead of fetching the prerendered examples.json it recursively calls itself in [id].json. My guess is that the runtime first tries to find a matching "live" route before checking if a prerendered one exists.

Reproduction

https://stackblitz.com/edit/sveltejs-kit-template-default-fhjdvp?file=src%2Froutes%2F%2Bpage.server.js

Logs

No response

System Info

SvelteKit 2.6.3

Severity

annoyance

Additional Information

can be worked around by making sure the routes don't match

[dummdidumm]

A variation of this is when you have a prerendered +server.js next to a non-prerendered +page(.server).js, and the load function wants to access the prerendered result. It doesn't end up in an infinite loop in this case but the bug is the same.

[eltigerchino]

We currently don't have any check for prerendered routes since they're removed from the manifest. We only have a check for static assets before it tries to respond with a route.

kit/packages/kit/src/runtime/server/fetch.js

Line 89 in 33600ee

if (is_asset || is_asset_html) {

Do you think we should re-include prerendered routes in the manifest somehow so that we can perform this check?

[dummdidumm]

Can also happen with spread routes as seen in #11927

[dummdidumm]

Probably related: #12739