On Mon, 7 Mar 2022 08:23:46 GMT, Conor Cleary <ccle...@openjdk.org> wrote:

>> **Problem**
>> When a Continuation Frame is received by the httpclient using HTTP/2 after a 
>> Push Promise frame (can happen if the amount of headers to be sent in a 
>> single Push Promise frame exceeds the maximum frame size, so a Continuation 
>> frame is required), the following exception occurs:
>> 
>> 
>> java.io.IOException: no statuscode in response
>> at 
>> java.net.http/jdk.internal.net.http.HttpClientImpl.send(HttpClientImpl.java:565)
>> at 
>> java.net.http/jdk.internal.net.http.HttpClientFacade.send(HttpClientFacade.java:119)
>> ...
>> 
>> This exception occurs because there is no existing flow in 
>> `jdk/internal/net/http/Http2Connection.java` which accounts for the case 
>> where a PushPromiseFrame is received with the END_HEADERS flag set to 0x0. 
>> When this occurs, the only acceptable frame/s (as multiple continuations are 
>> also acceptable) that can be received by the client on the same stream is a 
>> continuation frame.
>> 
>> **Fix**
>> To ensure correct behavior, the following changes were made to 
>> `jdk/internal/net/http/Http2Connection.java`.
>> 
>> - The existing method `handlePushPromise()` was modified so that if the 
>> END_HEADERS flag is _unset_ (flags equal to 0x0), then a record used to 
>> track the state of the Push Promise containing a shared `HeaderDecoder` and 
>> the received `PushPromiseFrame` is initialised.
>> - When the subsequent `ContinuationFrame` is received in `processFrame()`, 
>> the method `handlePushContinuation()` is called instead of the default flow 
>> resulting in `stream.incoming(frame)` being called (the source of the 
>> incorrect behaviour originally).
>> - In `handlePushContinuation()`, the shared decoder is used to decode the 
>> received `ContinuationFrame` headers and if the `END_HEADERS` flag is set 
>> (flags equal to 0x4), the `HttpHeaders` object for the Push Promise as a 
>> whole is constructed which serves to combine the headers from both the 
>> `PushPromiseFrame` and the `ContinuationFrame`.
>> 
>> A regression test was included which verifies that the exception is not 
>> thrown and that the headers arrive correctly.
>
> Conor Cleary has updated the pull request incrementally with one additional 
> commit since the last revision:
> 
>   8263031: Tidied up import statements

test/jdk/java/net/httpclient/http2/PushPromiseContinuation.java line 227:

> 225:             map.put("x-promise", List.of(mainPromiseBody));
> 226:             HttpHeaders headers = HttpHeaders.of(map, ACCEPT_ALL);
> 227:             exchange.serverPush(uri, headers, is);

Could create all of the headers here instead of in Http2LPPTestExchangeImpl, 
might improve readability of test.

-------------

PR: https://git.openjdk.java.net/jdk/pull/7696

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