Non-existent `__data.json` pages link to broken relative paths

[teemingc]

Describe the bug

When navigating to a non-existent page with the data suffix e.g., /example/__data.json, the error page fails to load the js and css assets. This is happening because we strip the data suffix in the request URL.

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

Lines 111 to 112 in c0f3c40

	url.pathname =
	strip_data_suffix(url.pathname) +

So, the asset relative paths are returned one directory short when SvelteKit thinks the request URL is /example instead of /example/__data.json.

Reproduction

1. Open https://stackblitz.com/edit/sveltejs-kit-template-default-lwxx8r?file=README.md
2. Run pnpm build && pnpm preview
3. Navigate to /anything/__data.json

Expected: Ordinary styled error page.

Actual: Unstyled error page.

Logs

No response

System Info

stackblitz

Severity

annoyance

Additional Information

No response