Fix Executor.asDispatcher() sometimes forgetting to cancel futures

Author: dkhalanskyjb

kotlinx-coroutines-core/jvm/src/Executors.kt

@@ -205,7 +205,7 @@ private class CancelFutureOnCancel(private val future: Future<*>) : CancelHandle
     override fun invoke(cause: Throwable?) {
         // Don't interrupt when cancelling future on completion, because no one is going to reset this
         // interruption flag and it will cause spurious failures elsewhere
-        if (cause != null) future.cancel(false)
+        future.cancel(false)
     }
     override fun toString() = "CancelFutureOnCancel[$future]"
 }

kotlinx-coroutines-core/jvm/test/ExecutorAsCoroutineDispatcherDelayTest.kt

@@ -38,4 +38,21 @@ class ExecutorAsCoroutineDispatcherDelayTest : TestBase() {
         executor.shutdown()
         assertEquals(1, callsToSchedule)
     }
+
+    @Test
+    fun testCancelling() = runTest {
+        val executor = STPE()
+        launch(start = CoroutineStart.UNDISPATCHED) {
+            suspendCancellableCoroutine<Unit> { cont ->
+                expect(1)
+                (executor.asCoroutineDispatcher() as Delay).scheduleResumeAfterDelay(1_000_000, cont)
+                cont.cancel()
+                expect(2)
+            }
+        }
+        expect(3)
+        assertTrue(executor.getQueue().isEmpty())
+        executor.shutdown()
+        finish(4)
+    }
 }