Empty Client Request Buffers Are Not Released

[alexwen]

Turning on ResourceLeakDetector#PARANOID; I was getting warnings from some of my tests which utilize an RxNetty HTTP Client:

10:45:16.876 [rx-selector-1-2] ERROR io.netty.util.ResourceLeakDetector - LEAK: ByteBuf.release() was not called before it's garbage-collected.
Recent access records: 0
Created at:
    io.netty.buffer.CompositeByteBuf.<init>(CompositeByteBuf.java:59)
    io.netty.buffer.Unpooled.compositeBuffer(Unpooled.java:355)
    io.netty.handler.codec.http.HttpObjectAggregator.decode(HttpObjectAggregator.java:151)
    io.netty.handler.codec.http.HttpObjectAggregator.decode(HttpObjectAggregator.java:52)
    io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:89)
    io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333)
    io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:319)
    io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:163)
    io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:148)
    io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333)
    io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:319)
    io.netty.handler.logging.LoggingHandler.channelRead(LoggingHandler.java:283)
    io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333)
    io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:319)
    io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
    io.reactivex.netty.metrics.BytesInspector.channelRead(BytesInspector.java:56)
    io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333)
    io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:319)
    io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:787)
    io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:125)
    io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
    io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
    io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
    io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
    io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116)
    io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137)
    java.lang.Thread.run(Thread.java:745)

I tracked this down to an issue with empty responses from the server. Since it is a CompositeBuffer, and not readable, the content is not being passed along to the client AND the reference is never being released. Although this may be innocuous (as the buffer is empty), it would be nice if these did not cause the LeakDetector to trigger.