HTTP/3: Hang when reading content or disposing response when SerializeToStreamAsync doesn't complete

[JamesNK]

Description

Dependency update from dotnet/aspnetcore#50362 caused new behavior in some tests.

Some tests hang on reading to the end of the response:

• POST_ServerCompletesWithoutReadingRequestBody_ClientGetsResponse hangs here

Some tests hang on disposing the response:

• POST_ClientCancellationBidirectional_RequestAbortRaised(protocol: Http3) hangs here

Consistent between the tests is we have streaming request content via StreamingHttpContent. In the tests we're not completing the request stream so SerializeToStreamAsync doesn't exit.

Note: The implementation of SerializeToStreamAsync is listening to the cancellation token. I don't know if it was canceled before and isn't now, or if it should be canceled at all, but it isn't when I debug the tests.

It seems like wrong behavior for the request stream not being completed to cause a hang when reading to the end of response data (the server in POST_ServerCompletesWithoutReadingRequestBody_ClientGetsResponse has sent its data and completed), or aborting the response via dispose.

Reproduction Steps

See tests above.

Expected behavior

Either:

• The cancellation token to SerializeToStreamAsync is canceled when the response finishes or the HttpResponseMessage.Dispose() is called, or
• SerializeToStreamAsync not exiting doesn't hang finishing reading the response or aborting

Actual behavior

Hangs

Regression?

Worked in .NET 8

Known Workarounds

No response

Configuration

.NET 9 latest from dotnet/aspnetcore#50362

Other information

No response

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Issue Details

---

Description

Dependency update from dotnet/aspnetcore#50362 caused new behavior in some tests.

Some tests hang on reading the response:

• POST_ServerCompletesWithoutReadingRequestBody_ClientGetsResponse hangs here

Some tests hang on disposing the response:

• POST_ClientCancellationBidirectional_RequestAbortRaised(protocol: Http3) hangs here

Consistent between the tests is we have streaming request content via StreamingHttpContent. In the tests we're not completing the request stream so SerializeToStreamAsync doesn't exit. The implementation of SerializeToStreamAsync is listening to the cancellation token and it isn't being canceled to cause the method to exit either.

It seems like wrong behavior for the request stream not being completed to cause a hang when reading the response data (the server in POST_ServerCompletesWithoutReadingRequestBody_ClientGetsResponse has sent its data and completed), or aborting the response via dispose.

Reproduction Steps

See tests above.

Expected behavior

Either:

• The cancellation token to SerializeToStreamAsync is canceled when the response finishes or the HttpResponseMessage.Dispose() is called, or
• SerializeToStreamAsync not exiting doesn't hang finishing reading the response or aborting

Actual behavior

Hangs

Regression?

Worked in .NET 8

Known Workarounds

No response

Configuration

.NET 9 latest from dotnet/aspnetcore#50362

Other information

No response

Author:	JamesNK
Assignees:	-
Labels:	area-System.Net.Http
Milestone:	-

[JamesNK]

Here is a real-world scenario:

• A client is streaming data to the server.
• Unexpected values in the data cause the server to end the response.
• The client stream is still open.
• The client will hang if:
  • It aborts the request with HttpResponseMessage.Dispose(), or
  • It is reading from the response and is waiting for data to be return or the response to end