Unexpected call to flush after transform stream destruction

[mafintosh]

• Version: 8.9.4
• Platform: Linux brunhilde 4.14.9-1-ARCH deps: update openssl to 1.0.1j #1 SMP PREEMPT Tue Dec 26 00:18:37 UTC 2017 x86_64 GNU/Linux
• Subsystem: streams

Running the below example

var stream = require('stream')

var t = stream.Transform({
  transform: function (data, enc, cb) {
    console.log(`transform destroyed=${this._readableState.destroyed}`)
    cb(null)
  },
  flush: function (cb) {
    console.log(`flush destroyed=${this._readableState.destroyed}`)
    cb(null)
  }
})

t.on('close', function () {
  console.log('onclose')
})

t.on('error', function () {
  console.log('onerror')
})

t.on('end', function () {
  console.log('onend')
})

t.on('finish', function () {
  console.log('onfinish')
})

t.resume()
t.write('a')
t.write('b')
t.write('c')
t.destroy(new Error('error'))

... I get the following output

transform destroyed=false
transform destroyed=false
transform destroyed=false
flush destroyed=true
onfinish
onend
onclose
onerror

The order of events here seem wrong (similar to #18171) as I would expect error to come before finish/end.

It also seems wrong that flush is called even though the stream has been destroyed.

[mafintosh]

/cc @mcollina @nodejs/streams

[BridgeAR]

@mafintosh @nodejs/streams what's the status here?

[mcollina]

This was fixed in Node 10 by #19836