only normalise internal URLs

[Rich-Harris]

fixes #5087, by only normalising URLs we're navigating to once we've established that it's a page within the app

Please don't delete this checklist! Before submitting the PR, please make sure you do the following:

• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests with pnpm test and lint the project with pnpm lint and pnpm check

Changesets

• If your PR makes a change that should be noted in one or more packages' changelogs, generate a changeset by running pnpm changeset and following the prompts. All changesets should be patch until SvelteKit 1.0

[changeset-bot]

🦋 Changeset detected

Latest commit: 5cd877b

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@sveltejs/kit	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[Rich-Harris]

can't reproduce these failures locally. hmm

[Rich-Harris]

oh hang on yes i can. they're in adapter-static tests, not kit 🤦

[benmccann]

lgtm. I have a nagging feeling we should be able to test this in a lighter way, but don't have any immediate suggestions. I think Routify and React Router do some unit tests by mocking the browser, which might work here longer-term

[Rich-Harris]

Maybe we could use network mocking https://playwright.dev/docs/test-configuration#network-mocking. I haven't used it so don't know if it's suitable, but possibly worth a try