Recover stacktrace on the fast-path of receiveOrNull

Author: qwwdfsad

kotlinx-coroutines-core/common/src/channels/AbstractChannel.kt

@@ -590,7 +590,8 @@ internal abstract class AbstractChannel<E> : AbstractSendChannel<E>(), Channel<E
     public final override suspend fun receiveOrNull(): E? {
         // fast path -- try poll non-blocking
         val result = pollInternal()
-        if (result !== POLL_FAILED) return receiveOrNullResult(result)
+        @Suppress("UNCHECKED_CAST")
+        if (result !== POLL_FAILED && result !is Closed<*>) return result as E
         // slow-path does suspend
         return receiveSuspend(RECEIVE_NULL_ON_CLOSE)
     }

kotlinx-coroutines-core/jvm/test-resources/stacktraces/channels/testReceiveOrNullFromClosedChannel.txt

@@ -0,0 +1,8 @@
+kotlinx.coroutines.RecoverableTestException
+	at kotlinx.coroutines.exceptions.StackTraceRecoveryChannelsTest$testReceiveOrNullFromClosedChannel$1.invokeSuspend(StackTraceRecoveryChannelsTest.kt:43)
+	(Coroutine boundary)
+	at kotlinx.coroutines.exceptions.StackTraceRecoveryChannelsTest.channelReceiveOrNull(StackTraceRecoveryChannelsTest.kt:70)
+	at kotlinx.coroutines.exceptions.StackTraceRecoveryChannelsTest$testReceiveOrNullFromClosedChannel$1.invokeSuspend(StackTraceRecoveryChannelsTest.kt:44)
+Caused by: kotlinx.coroutines.RecoverableTestException
+	at kotlinx.coroutines.exceptions.StackTraceRecoveryChannelsTest$testReceiveOrNullFromClosedChannel$1.invokeSuspend(StackTraceRecoveryChannelsTest.kt:43)
+	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)

kotlinx-coroutines-core/jvm/test/exceptions/StackTraceRecoveryChannelsTest.kt

@@ -37,6 +37,12 @@ class StackTraceRecoveryChannelsTest : TestBase() {
         channelReceive(channel)
     }
 
+    @Test
+    fun testReceiveOrNullFromClosedChannel() = runTest {
+        val channel = Channel<Int>()
+        channel.close(RecoverableTestException())
+        channelReceiveOrNull(channel)
+    }
 
     @Test
     fun testSendToClosedChannel() = runTest {
@@ -60,10 +66,13 @@ class StackTraceRecoveryChannelsTest : TestBase() {
         finish(4)
     }
 
-    private suspend fun channelReceive(channel: Channel<Int>) {
+    private suspend fun channelReceive(channel: Channel<Int>) = channelOp { channel.receive() }
+    private suspend fun channelReceiveOrNull(channel: Channel<Int>) = channelOp { channel.receiveOrNull() }
+
+    private suspend inline fun channelOp(block: () -> Unit) {
         try {
             yield()
-            channel.receive()
+            block()
             expectUnreached()
         } catch (e: RecoverableTestException) {
             verifyStackTrace("channels/${name.methodName}", e)