4.x: gRPC handler send :status headers twice

[lilac]

Environment Details

• Helidon Version:
  • Helidon SE
• JDK version: 21
• OS: Mac
• Docker version (if applicable):

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Problem Description

Calls to a simple echo gRPC server from Postman or other gRPC clients result in an internal error. The error message is like Received RST_STREAM with code 1.

Steps to reproduce

This issue can be reproduced every time a gRPC method is called from a strict gRPC client like postman. I've capture the data packets, and found the root cause of it: 2 headers frames both have set the:status header.

Below are quoted from the http/2 standard

Pseudo-header fields MUST NOT appear in a trailer section.

The same pseudo-header field name MUST NOT appear more than once in a field block. A field block for an HTTP request or response that contains a repeated pseudo-header field name MUST be treated as malformed (Section 8.1.1).

Apparently the current gRPC implementation does not conform to that.

First headers frame

Second headers frame