Spring WebFlux: LEAK: ByteBuf.release() was not called

[joke]

Hi,

the reactive implementations seems to have some memory leaks.
I would guess it's either CloudEventHttpMessageWriter or CloudEventHttpMessageReader but I'm not certain.

I build an example project with a very basic setup and the latest dependencies: joke/cloud-event-leak. You can run the CloudEventLeakApplicationTests which basically fires off some requests until a buffer leak is detected in stdout.

2021-10-14 16:08:08.112 ERROR 15530 --- [ctor-http-nio-3] io.netty.util.ResourceLeakDetector       : LEAK: ByteBuf.release() was not called before it's garbage-collected. See https://netty.io/wiki/reference-counted-objects.html for more information.
Recent access records: 
#1:
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:285)
	io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
	io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)
	io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
	io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
	io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
	io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
	io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	java.base/java.lang.Thread.run(Thread.java:834)

[joke]

The problem was a missing close on a stream CloudEventHttpMessageReader.