This PR is a small follow-up to #14705. It saves Next.js users from falling into a [pretty nasty trap](https://github.com/nodejs/node/issues/36620) in which I ended up last Friday. It took more than two days to investigate what was going on, so I hope I'm the last person who’s doing it 😅
Next.js-specific MWE: https://github.com/kachkaev/hanging-response-in-next-via-redirect-plus-compression (needs to be ran locally using Node 14.0.0+).
> <img width="521" alt="Screenshot 2020-12-24 at 20 50 00" src="https://user-images.githubusercontent.com/608862/103105989-a9b8dc00-4629-11eb-9be3-5108755604bf.png">
To reproduce the bug I’m fixing:
1. Pick a large http body size (64 or 128 KB)
1. Check _Call res.end() after res.redirect() in /api/redirect_
1. Navigate to a heavy page or an api handler via redirect
1. Observe that the http response is never finished.
If you set `compress` to `false` in `next.config.js` or pick a small payload size (< `zlib.Z_DEFAULT_CHUNK` after compression), the bug will not be observed. This is explained by the use of `res.on("drain", ...)` [by the `compression` package](3fea81d0ea/index.js (L193-L218)). The package itself is not the reason for an issue though, it seems to be in the Node’s built-in `http` package.
I’m happy to provide more info or GitHub CI to the MWE if needed. I was also thinking of adding some Next.js-specific testing, but could not come up with a compact and clear test plan. Happy to do this if there are any ideas.
cc @botv (author of #14705)
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