Reject whitespace in HttpListener chunk sizes

[Copilot]

main PR

Description

• Parsing: Retain the entire chunk-size field and parse only hexadecimal characters before an optional extension.
• Regression coverage: Add a raw chunked-request test that verifies a trailing space after the size is rejected.

5 \r\n
Hello\r\n

Customer Impact

Malformed chunked requests with whitespace in the size field are now rejected rather than accepted.

Regression

No.

Testing

Targeted and full HttpListener test coverage added/run.

Risk

Low. The managed parser now rejects invalid chunk-size syntax without changing valid hexadecimal sizes or semicolon extensions.

Package authoring no longer needed in .NET 9

IMPORTANT: Starting with .NET 9, you no longer need to edit a NuGet package's csproj to enable building and bump the version.
Keep in mind that we still need package authoring in .NET 8 and older versions.

Note

This PR description was generated by GitHub Copilot.

• Fixes HttpListener's chunk size parsing could be more strict #132746

[azure-pipelines]

Azure Pipelines:
16 pipeline(s) were filtered out due to trigger conditions.
There may be pipelines that require an authorized user to comment /azp run to run.

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/runtime-infrastructure
See info in area-owners.md if you want to be subscribed.