next.js

000e0880 - Re-fetch dynamic content on navigation with `partialPrefetching` enabled (#94655)

Re-fetch dynamic content on navigation with `partialPrefetching` enabled (#94655) With `partialPrefetching` enabled, navigating back to a page that was first loaded as a full HTML document served stale dynamic content. Its `connection()`-gated output kept showing the value from the original document load instead of being re-run per request, and the `<Link prefetch={true}>` navigation issued no server request at all. A page first reached through a prefetch behaved correctly, so the problem only surfaced after an initial HTML load. The cause was a missing prefetch hint on the route tree that the client caches from that initial HTML render. The app-page build template assembles the route module's `renderOpts` directly from `nextConfig`, and that field list carried `cacheComponents` and the `experimental` block but left out `partialPrefetching`. So `renderOpts.partialPrefetching` was `undefined` for every runtime render even with the flag on; only the build-time prerender and per-segment prefetch artifacts, produced through the export worker, had the correct value. As a result the route tree computed at runtime and inlined into the initial HTML lacked the `SubtreeHasPartialPrefetching` hint and picked up `SubtreeHasEagerPrefetch` instead. When that tree was later reused for a `prefetch={true}` navigation, the client never downgraded the full prefetch to a partial one, so it promoted the fully resolved hydration entry out of the bfcache into a non-partial segment and served it stale. The fix passes `nextConfig.partialPrefetching` through the template's `renderOpts` (kept raw so `'unstable_eager'` survives), so runtime renders emit the same hint as the build artifacts and the existing client-side downgrade handles the rest. A regression test navigates back to a page after its initial HTML load and asserts, via the router `act` helper, that the navigation re-fetches the dynamic content instead of serving it stale.