Is there any progress on this?

I can confirm the issue which seems to impact CoWebFilter as well on annotation-based programming model side cc @poutsma .

During filter + handler Coroutines use case, the handler should reuse the context defined by the filter and currently, it overrides it with Dispatchers.Unconfined when invoking the mono(Dispatchers.Unconfined) { } lambda at handler level. Using mono(Dispatchers.Unconfined) is ok when this is the "top level Coroutines invokation", but not when this is a handler 'nested' in a filter.

I guess the handler should reuse filter CoroutineContext when defined, but not sure yet how.

See potentially related issue #27522.

Looks like I have found a way to propagate correctly the CoroutineContext by introducing a HandlerFunction implementation that allows to pass explicitly the context:

abstract class ContextAwareHandlerFunction<T : ServerResponse> : HandlerFunction<T> {
	override fun handle(request: ServerRequest): Mono<T> {
		return handle(Dispatchers.Unconfined, request)
	}
	abstract fun handle(context: CoroutineContext, request: ServerRequest): Mono<T>
}

More details in this draft commit, feedback welcome.

Hello @sdeleuze
Thanks for your changes. I have related question:
In our application we are using webflux and our controllers annotated with @GetMapping annotation.
If I'm right you changes won't be applied for this case. There are used org.springframework.web.reactive.result.method.InvocableHandlerMethod#invoke

if (isSuspendingFunction) {
	value = CoroutinesUtils.invokeSuspendingFunction(method, getBean(), args);
}
else {
	value = method.invoke(getBean(), args);
}

Do you have any ideas how I can pass MDCContext() to suspended controller function, when MDC was set in CoWebFilter?
(I found related thread #27522)

With Spring Boot 3.2 + Spring Framework 6.1, I think that should be the case, if not please create an issue with a minimal reproducer as an attached project or a link to a repository.