next.js

1669edee - Hold `cacheSignal` across `unstable_cache` foreground revalidation (#93617)

Hold `cacheSignal` across `unstable_cache` foreground revalidation (#93617) When `unstable_cache` finds a stale entry during the prospective phase of a prerender, it dispatches a foreground revalidation and returns the in-flight promise. The wrapper's `cacheSignal.beginRead` / `endRead` pair was scoped only to the synchronous lookup.`endRead` in the outer `finally` fires the moment the function returns the promise, before the recompute and `cacheNewResult` have completed. The prospective prerender's `cacheSignal` then resolves `cacheReady` while the recompute is still in flight, ending the prospective phase early. Any `'use cache'` invocation rendered after the `unstable_cache` await in the same component never gets reached, so its RDC entry is never populated, and the final prerender phase throws "Unexpected cache miss after cache warming phase during prerendering." Returning `await pendingRevalidates[invocationKey]` instead of returning the promise directly keeps the wrapper function suspended until the recompute and `cacheNewResult` actually complete. The outer `finally` then runs `endRead` at the right time, the prospective phase keeps waiting, and downstream `'use cache'` invocations are reached and populate the RDC as expected. Adds a regression test under the `use-cache` suite that exercises an `unstable_cache` await followed by a downstream `'use cache'` component. Without the fix, the test fails consistently under `__NEXT_CACHE_COMPONENTS=true` with the cache-miss-after-warming error.