up/down keys on Windows have broken behavior in windows

[martinheidegger]

At nodeschool we have had reports for a while that the workshoppers don't work on windows. Issues for reference: workshopper#420 nodeschool/discussions#1641.

After some research I found out that from Node 5.6 on it seems like some system code is overriding the cursor up/down behavior in the rawmode of tty.

Since it is a bit hard to explain I prepared a short video showing the behavior. Youtube Link

It uses the following script:

var stdin = process.stdin;

stdin.on('data', function (data) {
  data = data.toString()
  console.log(data.split("").map(function (chr) { return chr.charCodeAt(0) }))
  process.exit();
})
stdin.resume()
stdin.setRawMode(true)

Gist

• Version: Node 5.6 +
• Platform: Definitely tested on Windows 10
• Subsystem: process.stdin

[Fishrock123]

Hmmm I didn't see anything obvious from v5.6.0's commit log. I don't think this is the same issue as #5776 either.

cc @nodejs/platform-windows

[Fishrock123]

Hmm, maybe it is this same bug. The c-ares upgrade was in 5.6.0.

[martinheidegger]

Seems like it is the same bug (why didn't it show up in my search for issues)

[orangemocha]

I think this is likely to be the same as #5384. Investigating that issue I found that accessing process.stdin causes asynchronous reads to be started and then canceled. So there is a race condition between those reads being canceled and the console being set in raw mode. If the reads don't get canceled in time, they will consume keypress events from the system buffers before the console is set in raw mode.

tl;dr: could you please test the change at #5776 and see if it solves this issue?

[martinheidegger]

@orangemocha Seems like that issue was reverted. But it does sound like we are talking about the same issue.

[jasnell]

Closing as a duplicate of #5384. The issue still exists we just don't need multiple issues open for it! It's being investigated still! Thank you!