Let's see how it works :)

Author: ndkoval

kotlinx-coroutines-core/common/src/CancellableContinuationImpl.kt

@@ -21,7 +21,7 @@ private const val RESUMED = 2
 private inline val Int.decision get() = this shr DECISION_SHIFT
 private inline val Int.index get() = this and INDEX_MASK
 @Suppress("NOTHING_TO_INLINE")
-private inline fun construct(decision: Int, index: Int) = decision shl DECISION_SHIFT + index
+private inline fun construct(decision: Int, index: Int) = (decision shl DECISION_SHIFT) + index
 
 @JvmField
 @SharedImmutable
@@ -182,7 +182,7 @@ internal open class CancellableContinuationImpl<in T>(
         _state.loop { state ->
             if (state !is NotCompleted) return false // false if already complete or cancelling
             // Active -- update to final state
-            val update = CancelledContinuation(this, cause, handled = state is CancelHandler)
+            val update = CancelledContinuation(this, cause, handled = state is CancelHandler || state is Segment<*>)
             if (!_state.compareAndSet(state, update)) return@loop // retry on cas failure
             // Invoke cancel handler if it was present
             (state as? CancelHandler)?.let { callCancelHandler(it, cause) }
@@ -224,9 +224,9 @@ internal open class CancellableContinuationImpl<in T>(
         callCancelHandlerSafely { handler.invoke(cause) }
 
     fun callSegmentOnCancellation(segment: Segment<*>, cause: Throwable?) {
-        val index = _decisionAndIndex.getAndUpdate { construct(it.decision, NO_INDEX) }.index
-        check(index != NO_INDEX) { "The index for segment.invokeOnCancellation(..) is broken" }
-        callCancelHandlerSafely { segment.invokeOnCancellation(index, cause) }
+//        val index = _decisionAndIndex.getAndUpdate { construct(it.decision, NO_INDEX) }.index
+//        check(index != NO_INDEX) { "The index for segment.invokeOnCancellation(..) is broken" }
+//        callCancelHandlerSafely { segment.invokeOnCancellation(index, cause) }
     }
 
 
@@ -368,7 +368,7 @@ internal open class CancellableContinuationImpl<in T>(
                 is Active -> {
                     if (_state.compareAndSet(state, handler)) return // quit on cas success
                 }
-                is CancelHandler -> multipleHandlersError(handler, state)
+                is CancelHandler, is Segment<*> -> multipleHandlersError(handler, state)
                 is CompletedExceptionally -> {
                     /*
                      * Continuation was already cancelled or completed exceptionally.