Tim NeutkensandGitHub f2ddd134e7 Fix non-RSC router prefetch handling (#94553) ...

### What?

Ignore router prefetch protocol headers when the request is not
classified as an RSC request. Add a dedicated force-dynamic App Router
fixture that verifies HTML and valid RSC prefetch behavior.

### Why?

A non-RSC HTML request with `Next-Router-Prefetch: 1` could enter the
partial prefetch tree path, produce a null active cache node, and
suspend the HTML render until timeout.

### How?

Determine `isRSCRequest` before parsing prefetch modes, then require it
for prefetch modes `1`, `2`, and `3`, including route-tree prefetch
classification. The regression fixture uses an abort timeout to fail
quickly if the HTML response hangs and separately confirms RSC
prefetches remain valid.

### Verification

- `pnpm build-all`
- `NEXT_TEST_PREFER_OFFLINE=1 pnpm test-start-turbo
test/e2e/app-dir/non-rsc-router-prefetch/non-rsc-router-prefetch.test.ts`
- `NEXT_TEST_PREFER_OFFLINE=1 pnpm test-start-webpack
test/e2e/app-dir/non-rsc-router-prefetch/non-rsc-router-prefetch.test.ts`
- `pnpm --filter=next types`

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2026-06-17 17:41:01 +02:00

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app

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next.config.js

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non-rsc-router-prefetch.test.ts

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