withTimeoutOrNull+channel hangs

[fvasco]

I detected a strange behaviour in the follow code:

import kotlinx.coroutines.GlobalScope
import kotlinx.coroutines.channels.*
import kotlinx.coroutines.delay
import kotlinx.coroutines.withTimeoutOrNull
import kotlinx.coroutines.yield

suspend fun main() {
    repeat(100) { step ->
        println("step $step")

        val producer = GlobalScope.produce(capacity = 1024 * 1024) {
            repeat(1_000_000) {
                send(it)
                yield()
            }
            println("End producer")
        }

        val consumer = GlobalScope.actor<Int?>(capacity = Channel.CONFLATED) {
            while (true) receive()
        }

        producer.receive()
        delay(200)

        withTimeoutOrNull(100) {
            while (true) consumer.send(producer.receiveOrNull())
        }
        producer.cancel()
    }
}

it hangs with output

step 0
step 1
step 2
End producer

Kotlin 1.3.40
Coroutine 1.2.2
Java adoptopenjdk-12-jdk-hotspot

[fvasco]

As documented receiveOrNull "does not check for cancellation when it is not suspended"