Motivation
Pipeline handlers are free to "take control" of input buffers if they have singular refcount - in particular to mutate their raw data if non-readonly via discarding of read bytes, etc.
However there are various places (primarily unit tests) where a wrapped byte-array buffer is passed in and the wrapped array is assumed not to change (used after the wrapped buffer is passed to EmbeddedChannel.writeInbound()). This invalid assumption could result in unexpected errors, such as those exposed by #8931.
Modifications
Anywhere that the data passed to writeInbound() might be used again, ensure that either:
- A copy is used rather than wrapping a shared byte array, or
- The buffer is otherwise protected from modification by making it read-only
For the tests, copying is preferred since it still allows the "mutating" optimizations to be exercised.
Results
Avoid possible errors when pipeline assumes it has full control of input buffer.
Motivation:
We did manually call HttpObjectDecoder.reset() in HttpObjectAggregator.handleOversizedMessage(...) which is incorrect and will prevent correct parsing of the next message.
Modifications:
- Remove call to HttpObjectDecoder.reset()
- Add unit test
Result:
Verify that we can correctly parse the next request after we rejected a request.
Motivation:
RFC 6455 defines that, generally, a WebSocket client should not close a TCP
connection as far as a server is the one who's responsible for doing that.
In practice tho', it's not always possible to control the server. Server's
misbehavior may lead to connections being leaked (if the server does not
comply with the RFC).
RFC 6455 #7.1.1 says
> In abnormal cases (such as not having received a TCP Close from the server
after a reasonable amount of time) a client MAY initiate the TCP Close.
Modifications:
* WebSocket client handshaker additional param `forceCloseAfterMillis`
* Use 10 seconds as default
Result:
WebSocket client handshaker to comply with RFC. Fixes#8883.
Motivation:
32563bfcc1 introduced a regression in which we did now not longer discard the messages after we handled an oversized message.
Modifications:
- Do not set aggregating to false after handleOversizedMessage is called
- Adjust unit tests to verify the behaviour is correct again.
Result:
Fixes https://github.com/netty/netty/issues/9007.
Motivation:
Add user possibility to skip the evaluation of certain web socket extension,
for example we can skip compression extension for messages that already compressed or very small and etc.
Modification:
This pull request is related with #5669
Result:
User can set to WebSocketClientExtensionHandshaker or WebSocketServerExtensionHandshaker a filter to skip the evaluation of certain extension.
Motivation:
According to the specification, the "Connection" header's syntax is:
"
The Connection header field's value has the following grammar:
Connection = 1#connection-option
connection-option = token
Connection options are case-insensitive.
"
https://tools.ietf.org/html/rfc7230#section-6.1
This means that Connection's value can have at least one element or
a comma separated list with elements
When calculating whether the connection can remain open,
HttpUtil.isKeepAlive(HttpMessage) should take this into account.
Modifications:
- Check for "close" and "keep-alive" in a comma separated list
- Add unit test
Result:
HttpUtil.isKeepAlive(HttpMessage) works correctly when "Connection: Upgrade, close"
Motivation:
When HttpContentDecoder (and so HttpContentDecompressor) does not produce any message we need to make sure it calls ctx.read() if auto read is false to not stale.
Modifications:
- Keep track if we need to call ctx.read() or not
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/8915.
Motivation:
Gracefully respond on bad client request.
We have a set of errors produced by Android 7.1.1/7.1.2 clients where both headers `HttpHeaderNames.SEC_WEBSOCKET_VERSION` and `HttpHeaderNames.ORIGIN` are not present. Absence of the first headers leads to WebSocketServerHandshaker00 be applied as a handshaker. However, null 2nd header causes
```
java.lang.NullPointerException: value
io.netty.util.internal.ObjectUtil.checkNotNull(ObjectUtil.java:33)
io.netty.handler.codec.DefaultHeaders.addObject(DefaultHeaders.java:327)
io.netty.handler.codec.http.DefaultHttpHeaders.add(DefaultHttpHeaders.java:123)
io.netty.handler.codec.http.websocketx.WebSocketServerHandshaker00.newHandshakeResponse(WebSocketServerHandshaker00.java:162)
```
Which causes connection close with unclear reason.
Modification:
Added null-check, and in case of null an appropriate WebSocketHandshakeException is thrown.
Result:
In case of null `HttpHeaderNames.ORIGIN` header a WebSocketHandshakeException is caught by WebSocketServerProtocolHandler which sends a graceful `BAD_REQUEST`.
Motivation
Implementations of MessageAggregator (HttpObjectAggregator in particular) may wish to
selectively aggrerage requests and responses on a case-by-case basis such as for example
only POST requests or only responses of a certain content-type.
Modifications
Adding a flag to MessageAggregator that toggles between true/false depending on if aggregation
is desired for the current message or not.
Result
Fixes#8772
* HttpObjectDecoder ignores HTTP trailer header when empty line is received in seperate ByteBuf
Motivation:
When the empty line that termines the trailers was sent in a seperate ByteBuf we did ignore the previous parsed trailers and just returned none.
Modifications:
- Correct respect previous parsed trailers.
- Add unit test.
Result:
Fixes https://github.com/netty/netty/issues/8736
Motivation:
We need to update to a new checkstyle plugin to allow the usage of lambdas.
Modifications:
- Update to new plugin version.
- Fix checkstyle problems.
Result:
Be able to use checkstyle plugin which supports new Java syntax.
Motivation:
I want to fix bug in vert.x project (eclipse-vertx/vert.x#2562) caused by ComposedLastHttpContent result being null. I don't know if it is intentional that this last decoded chuck in the issue returns null, but if not - I am providing fix for that.
Modification:
* Added new constructor in ComposedLastHttpContent allowing to pass DecoderResult
* set DecoderResult.SUCCESS for created ComposedLastHttpContent in HttpContentEncoder
* set DecoderResult.SUCCESS for created ComposedLastHttpContent in HttpContentDecoder
Result:
Fixeseclipse-vertx/vert.x#2562
Motivation:
The CorruptedFrameException from the finish() method of the Utf8Validator gets propagated to other handlers while the connection is still open.
Modification:
Override exceptionCaught method of the Utf8FrameValidator and close the connection if it is a CorruptedFrameException.
Result:
The CorruptedFrameException gets propagated to other handlers only after properly closing the connection.
Motivation:
RFC 6455 doesn't define close status codes 1012, 1013 and 1014.
Yet, since then, IANA has defined them and web browsers support them.
From https://www.iana.org/assignments/websocket/websocket.xhtml:
* 1012: Service Restart
* 1013: Try Again Later
* 1014: The server was acting as a gateway or proxy and received an invalid response from the upstream server. This is similar to 502 HTTP Status Code.
Modification:
Make status codes 1012, 1013 and 1014 legit.
Result:
WebSocket status codes as defined by IANA are supported.
Motivation:
RFC 6455 doesn't define status codes 1012, 1013 and 1014.
Yet, since then, IANA has defined them, web browsers support them, applications in the wild do use them but it's currently not possible to buid a Netty based client for those services.
From https://www.iana.org/assignments/websocket/websocket.xhtml:
* 1012: Service Restart
* 1013: Try Again Later
* 1014: The server was acting as a gateway or proxy and received an invalid response from the upstream server. This is similar to 502 HTTP Status Code.
Modification:
Make status codes 1012, 1013 and 1014 legit.
Result:
WebSocket status codes as defined by IANA are supported.
Motivation:
According to the HTTP spec set-cookie headers should not be combined
because they are not using the list syntax.
Modifications:
Do not combine set-cookie headers.
Result:
Set-Cookie headers won't be combined anymore
Motivation:
As mentioned in RFC 7692 :
The "server_no_context_takeover" Extension Parameter should be used on server side for compression and on client side for decompression.
The "client_no_context_takeover" Extension Parameter should be used on client side for compression and on server side for decompression.
Right now, in PerMessageDeflateClientExtensionHandshaker, the decoder uses clientNoContext instead of serverNoContext and the encoder uses serverNoContext instead of clientNoContext.
The same inversion is present in PerMessageDeflateServerExtensionHandshaker: the decoder uses
serverNoContext instead of clientNoContext, while the encoder uses serverNoContext instead of clientNoContext. Besides the context inversion, the sliding window sizes seem to be inversed as well.
Modification:
Inverse clientNoContext with serverNoContext and clientWindowSize with serverWindowSize for both the Decoder and Encoder in PerMessageDeflateServerExtensionHandshaker and PerMessageDeflateClientExtensionHandshaker.
Result:
This fixes the decompression fail in the case that one of the contexts is set and the other one is not.
Motivation:
Get charset from Content-Type header even it contains multiple parameters.
Modification:
Extract charset value from the charset parameter if it is not last.
Result:
Fixes#8273
Motivation:
Implementation of WebSocketUtil/randomNumber is incorrect and might violate
the API returning values > maximum specified.
Modifications:
* WebSocketUtil/randomNumber is reimplemented, the idea of the solution described
in the comment in the code
* Implementation of WebSocketUtil/randomBytes changed to nextBytes method
* PlatformDependet.threadLocalRandom is used instead of Math.random to improve efficiency
* Added test cases to check random numbers generator
* To ensure corretness, we now assert that min < max when generating random number
Result:
WebSocketUtil/randomNumber always produces correct result.
Covers https://github.com/netty/netty/issues/8023
Motivation:
If a wrapped cookie value with an invalid charcater is passed to the strict
encoder, an exception is thrown on validation but the error message contains
a character at the wrong position.
Modifications:
Print `unwrappedValue.charAt(pos)` instead of `value.charAt(pos)`.
Result:
The exception indicates the correct invalid character in the unwrapped cookie.
Motivation:
Currently, when passing custom headers to a WebSocketClientHandshaker,
if values are added for headers that are reserved for use in the
websocket handshake performed with the server, these custom values can
be used by the server to compute the websocket handshake challenge. If
the server computes the response to the challenge with the custom header
values, rather than the values computed by the client handshaker, the
handshake may fail.
Modifications:
Update the client handshaker implementations to add the custom header
values first, and then set the reserved websocket header values.
Result:
Reserved websocket handshake headers, if present in the custom headers
passed to the client handshaker, will not be propagated to the server.
Instead the client handshaker will propagate the values it generates.
Fixes#7973.
Motivation:
The websockets abstract test suite does not run against the 08
implementation in the 08 version of the test suite.
Modifications:
Update the WebSocketClientHandshaker08Test to instantiate a new
WebSocketClientHandshaker08 rather than an 07 handshaker.
Result:
The WebSocketClientHandshaker08Test now tests the 08 implementation.
Motivation:
Currently, on recipt of a PongWebSocketFrame, the
WebSocketProtocolHandler will drop the frame, rather than passing it
along so it can be referenced by other handlers.
Modifications:
Add boolean field to WebSocketProtocolHandler to indicate whether Pong
frames should be dropped or propagated, defaulting to "true" to preserve
existing functionality.
Add new constructors to the client and server implementations of
WebSocketProtocolHandler that allow for overriding the behavior for the
handling of Pong frames.
Result:
PongWebSocketFrames are passed along the channel, if specified.
Motivation:
DefaultHttpResponse did not respect its status when compute the hashCode and check for equality.
Modifications:
Correctly implement hashCode and equals
Result:
Fixes https://github.com/netty/netty/issues/7964.
Motivation:
HTTP responses with status of 205 should not contain a payload. We should enforce this.
Modifications:
Correctly handle responses with status 205 and payload by set Content-Length: 0 header and stripping out the content.
Result:
Fixes https://github.com/netty/netty/issues/7888
Motivation:
It should be possible to call setContent(Unpooled.EMPTY_BUFFER) multiple times just like its possible to do the same with a non empty buffer.
Modifications:
- Correctly reset underlying storage if called multiple times.
- Add tests
Result:
Fixes https://github.com/netty/netty/issues/6418
Motivation:
NPE in `CorsHandler` if a pre-flight request is done using an Origin header which is not allowed by any `CorsConfig` passed to the handler on creation.
Modifications:
During the pre-flight, check the `CorsConfig` for `null` and handle it correctly by not returning any access-control header
Result:
No more NPE for pre-flight requests with unauthorized origins.
Motivation:
Finer granularity when configuring CorsHandler, enabling different policies for different origins.
Modifications:
The CorsHandler has an extra constructor that accepts a List<CorsConfig> that are evaluated sequentially when processing a Cors request
Result:
The changes don't break backwards compatibility. The extra ctor can be used to provide more than one CorsConfig object.
Motivation:
NPE in `ClientCookieDecoder` if cookie starts with comma.
Modifications:
Check `cookieBuilder` for `null` in the return.
Result:
No fails NPE on invalid cookies.
Motivation:
There may be meaningful 'connection' headers that exist on a request
that is used to attempt a HTTP/1.x upgrade request that will be
clobbered.
Modifications:
HttpClientUpgradeHandler uses the `HttpHeaders.add` instead of
`HttpHeaders.set` when adding the 'upgrade' field.
Result:
Fixes#7823, existing 'connection' headers are preserved.
Motivation:
There is a race between both flushing the upgrade response and receiving
more data before the flush ChannelPromise can fire and reshape the
pipeline. Since We have already committed to an upgrade by writing the
upgrade response, we need to be immediately prepared for handling the
next protocol.
Modifications:
The pipeline reshaping logic in HttpServerUpgradeHandler has been moved
out of the ChannelFutureListener attached to the write of the upgrade
response and happens immediately after the writeAndFlush call, but
before the method returns.
Result:
The pipeline is no longer subject to receiving more data before the
pipeline has been reformed.
Motivation:
HttpProxyHandler uses `NetUtil#toSocketAddressString` to compute
CONNECT url and Host header.
The url is correct when the address is unresolved, as
`NetUtil#toSocketAddressString` will then use
`getHoststring`/`getHostname`. If the address is already resolved, the
url will be based on the IP instead of the hostname.
There’s an additional minor issue with the Host header: default port
443 should be omitted.
Modifications:
* Introduce NetUtil#getHostname
* Introduce HttpUtil#formatHostnameForHttp to format an
InetSocketAddress to
HTTP format
* Change url computation to favor hostname instead of IP
* Introduce HttpProxyHandler ignoreDefaultPortsInConnectHostHeader
parameter to ignore 80 and 443 ports in Host header
Result:
HttpProxyHandler performs properly when connecting to a resolved address
Motivation:
When the response is very small, compression will inflate the response.
Modifications:
Add filed io.netty.handler.codec.http.HttpContentCompressor#compressThreshold that control whether the HTTP response should be compressed.
Result:
Fixes#7660.
Motivation:
A Malformed empty header value (e.g. Content-Type: \r\n) will trigger a String index out of range
while trying to parse the multi-part request, using the HttpPostMultipartRequestDecoder.
Modification:
Ensure that the substring() method is called passing the endValue >= valueStart.
In case of an empty header value, the empty header value associated with the header key will be returned.
Result:
Fixes#7620
Motivation:
Usages of HttpResponseStatus may result in more object allocation then necessary due to not looking for cached objects and the AsciiString parsing method not being used due to CharSequence method being used instead.
Modifications:
- HttpResponseDecoder should attempt to get the HttpResponseStatus from cache instead of allocating a new object
- HttpResponseStatus#parseLine(CharSequence) should check if the type is AsciiString and redirect to the AsciiString parsing method which may not require an additional toString call
- HttpResponseStatus#parseLine(AsciiString) can be optimized and doesn't require and may not require object allocation
Result:
Less allocations when dealing with HttpResponseStatus.
Motivation:
DefaultHttpDataFactory uses HttpRequest as map keys.
Because of the implementation of "hashCode"" and "equals" in DefaultHttpRequest,
if we use normal maps, HttpDatas of different requests may end up in the same map entry,
causing cleanup bug.
Consider this example:
- Suppose that request1 is equal to request2, causing their HttpDatas to be stored in one single map entry.
- request1 is cleaned up first, while request2 is still being decoded.
- Consequently request2's HttpDatas are suddenly gone, causing NPE, or worse loss of data.
This bug can be reproduced by starting the HttpUploadServer example,
then run this command:
ab -T 'application/x-www-form-urlencoded' -n 100 -c 5 -p post.txt http://localhost:8080/form
post.txt file content:
a=1&b=2
There will be errors like this:
java.lang.NullPointerException
at io.netty.handler.codec.http.multipart.MemoryAttribute.getValue(MemoryAttribute.java:64)
at io.netty.handler.codec.http.multipart.MixedAttribute.getValue(MixedAttribute.java:243)
at io.netty.example.http.upload.HttpUploadServerHandler.writeHttpData(HttpUploadServerHandler.java:271)
at io.netty.example.http.upload.HttpUploadServerHandler.readHttpDataChunkByChunk(HttpUploadServerHandler.java:230)
at io.netty.example.http.upload.HttpUploadServerHandler.channelRead0(HttpUploadServerHandler.java:193)
at io.netty.example.http.upload.HttpUploadServerHandler.channelRead0(HttpUploadServerHandler.java:66)
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102)
at io.netty.handler.codec.MessageToMessageCodec.channelRead(MessageToMessageCodec.java:111)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:284)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1412)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:943)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:141)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:645)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:580)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:497)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:459)
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:886)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.lang.Thread.run(Thread.java:748)
Modifications:
Keep identity of requests by using IdentityHashMap
Result:
DefaultHttpDataFactory is fixed.
The ConcurrentHashMap is replaced with a synchronized map, but I think the performance won't be affected much in real web apps.
Motivation:
HttpObjectDecoder will throw a TooLongFrameException when either the max size for the initial line or the header size was exceeed. We have no tests for this.
Modifications:
Add test cases.
Result:
More tests.
Motivation:
DefaultHttpHeader.names() exposes HTTP header names as a Set<String>. Converting the resulting set to an array using toArray(String[]) throws an exception: java.lang.ArrayStoreException: io.netty.util.AsciiString.
Modifications:
- Remove our custom implementation of toArray(...) (and others) by just extending AbstractCollection.
- Add unit test
Result:
Fixes [#7428].
Motivation:
For debugging/logging purpose, it would be convenient to have
HttpHeaders#toString implemented.
DefaultHeaders does implement toString be the implementation is suboptimal and allocates a Set for the names and Lists for values.
Modification:
* Introduce HeadersUtil#toString that provides a convenient optimized helper to implement toString for various headers implementations
* Have DefaultHeaders#toString and HttpHeaders#toString delegate their toString implementation to HeadersUtil
Result:
Convenient HttpHeaders#toString. Optimized DefaultHeaders#toString.
Motivation:
Its possible that cleanup() will throw if invalid data is passed into the wrapped EmbeddedChannel. We need to ensure we still call channelInactive(...) in this case.
Modifications:
- Correctly forward Exceptions caused by cleanup()
- Ensure all content is released when cleanup() throws
- Add unit tests
Result:
Correctly handle the case when cleanup() throws.
Motivation:
https://github.com/netty/netty/issues/7418 reported an issue with writing a LastHttpContent with trailers set.
Modifications:
Add unit test to ensure this issue is fixed in latest netty release.
Result:
Ensure code is correct.
Motivation:
In order to determine if a header contains a value we currently rely
upon getAll(..) and regular expressions. This operation is commonly used
during the encode and decode stage to determine the transfer encoding
(e.g. HttpUtil#isTransferEncodingChunked). This operation requires an
intermediate collection and possibly regular expressions for the
CombinedHttpHeaders use case which can be expensive.
Modifications:
- Add a valuesIterator to HttpHeaders and specializations of this method
for DefaultHttpHeaders, ReadOnlyHttpHeaders, and CombinedHttpHeaders.
Result:
Less intermediate collections and allocation overhead when determining
if HttpHeaders contains a name/value pair.
Motivation:
If the HttpUtil class is initialized before HttpHeaders or
EmptyHttpHeaders, EmptyHttpHeaders.INSTANCE will be null. This
can lead to NPEs in code that relies on this field being
non-null. One example is the
LastHttpContent.EMPTY_LAST_CONTENT.trailingHeaders method.
Modifications:
- Move HttpUtil.EMPTY_HEADERS to a private static final inner class
of EmptyHttpHeaders called InstanceInitializer.
- Add tests, that when run in isolation, validate the fix for the issue.
Result:
Any initialization order of HttpUtil, EmptyHttpHeaders or
HttpHeaders will result in EmptyHttpHeaders.INSTANCE being initialized
correctly.
Motivation:
According to RFC 7231 the server may choose to:
```
indicate a zero-length payload for the response by including a
Transfer-Encoding header field with a value of chunked and a message
body consisting of a single chunk of zero-length
```
https://tools.ietf.org/html/rfc7231#page-53
In such cases the exception below appears during decoding phase:
```
java.lang.IllegalArgumentException: invalid version format: 0
at io.netty.handler.codec.http.HttpVersion.<init>(HttpVersion.java:121)
at io.netty.handler.codec.http.HttpVersion.valueOf(HttpVersion.java:76)
at io.netty.handler.codec.http.HttpResponseDecoder.createMessage(HttpResponseDecoder.java:118)
at io.netty.handler.codec.http.HttpObjectDecoder.decode(HttpObjectDecoder.java:219)
```
Modifications:
HttpObjectDecoder.isContentAlwaysEmpty specifies content NOT empty
when 205 Reset Content response
Result:
There is no `IllegalArgumentException: invalid version format: 0`
when handling 205 Reset Content response with transfer-encoding
Motivation:
93130b172a introduced a regression where we not "converted" an empty HttpContent to ByteBuf and just passed it on in the pipeline. This can lead to the situation that other handlers in the pipeline will see HttpContent instances which is not expected.
Modifications:
- Correctly convert HttpContent to ByteBuf when empty
- Add unit test.
Result:
Handlers in the pipeline will see the expected message type.
Motivation:
For use cases that create headers, but do not need to modify them a read only variant of HttpHeaders would be useful and may be able to provide better iteration performance for encoding.
Modifications:
- Introduce ReadOnlyHttpHeaders that is backed by a flat array
Result:
ReadOnlyHttpHeaders exists for non-modifiable HttpHeaders use cases.
Motivation:
7995afee8f introduced a change that broke special handling of WebSockets 00.
Modifications:
Correctly delegate to super method which has special handling for WebSockets 00.
Result:
Fixes [#7362].
Motivation:
HttpObjectEncoder and MessageAggregator treat buffers that are not readable special. If a buffer is not readable, then an EMPTY_BUFFER is written and the actual buffer is ignored. If the buffer has already been released then this will not be correct as the promise will be completed, but in reality the original content shouldn't have resulted in any write because it was invalid.
Modifications:
- HttpObjectEncoder should retain/write the original buffer instead of using EMPTY_BUFFER
- MessageAggregator should retain/write the original ByteBufHolder instead of using EMPTY_BUFFER
Result:
Invalid write operations which happen to not be readable correctly reflect failed status in the promise, and do not result in any writes to the channel.
