Ensure ByteBuf#release is invoked for already sent HTTP/2 response

[violetagg]

Fix the observed exception:

java.lang.IllegalStateException: Stream 3 in unexpected state HALF_CLOSED_LOCAL
	at io.netty.handler.codec.http2.DefaultHttp2ConnectionEncoder.writeData(DefaultHttp2ConnectionEncoder.java:135)
	at io.netty.handler.codec.http2.DecoratingHttp2FrameWriter.writeData(DecoratingHttp2FrameWriter.java:39)
	at io.netty.handler.codec.http2.Http2FrameCodec.write(Http2FrameCodec.java:310)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:895)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:875)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:984)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:868)
	at io.netty.handler.codec.http2.AbstractHttp2StreamChannel.write0(AbstractHttp2StreamChannel.java:1192)
	at io.netty.handler.codec.http2.AbstractHttp2StreamChannel$Http2ChannelUnsafe.writeHttp2StreamFrame(AbstractHttp2StreamChannel.java:1045)
	at io.netty.handler.codec.http2.AbstractHttp2StreamChannel$Http2ChannelUnsafe.write(AbstractHttp2StreamChannel.java:1003)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.write(DefaultChannelPipeline.java:1367)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:889)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:875)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:984)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:868)
	at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:113)
	at io.netty.handler.codec.MessageToMessageCodec.write(MessageToMessageCodec.java:116)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:891)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:875)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:984)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:868)
	at reactor.netty.http.server.Http2StreamBridgeServerHandler.write(Http2StreamBridgeServerHandler.java:181)

A similar implementation is done for HTTP/1.1

reactor-netty/reactor-netty-http/src/main/java/reactor/netty/http/server/HttpTrafficHandler.java

Lines 371 to 381 in 066a645

	if (persistentConnection && pendingResponses == 0) {
	if (HttpServerOperations.log.isDebugEnabled()) {
	HttpServerOperations.log.debug(
	format(ctx.channel(), "Dropped HTTP content, since response has been sent already: {}"),
	msg instanceof HttpObject ?
	httpMessageLogFactory.debug(HttpMessageArgProviderFactory.create(msg)) : msg);
	}
	ReferenceCountUtil.release(msg);
	promise.setSuccess();
	return;
	}

[violetagg]

Failed tests on CI are not related

[violetagg]

@pderop Thanks!