GRPC server seems to always compress messages even if client does not support it.

[RubenGarcia]

GRPC server seems to always compress messages even if client does not support it. See https://github.com/Cysharp/YetAnotherHttpHandler/issues/19 where client is complaining with the line Request sent 'identity' grpc-encoding value with compressed message. #19 grpc: dependency: "direct main" description: name: grpc sha256: "220ffb2218288f4e7dea487242e08b9c6277596d9b6f3f10ba50be96771a032d" url: "https://pub.dev" source: hosted version: "3.2.3" ## Repro steps 1. Generate a dart grpc server 2. Use Unity and YetAnotherHttpHandler to connect to it Expected result: The client receives the correct answer Actual result: Request sent 'identity' grpc-encoding value with compressed message. #19

[RubenGarcia]

Removing compression using

 codecRegistry: CodecRegistry(codecs: const [/*GzipCodec(), */IdentityCodec()]),

does not make a difference.

[RubenGarcia]

Version: "3.2.4" is also affected.

[RubenGarcia]

Tested on android and on osx, both platforms have the issue.

[RubenGarcia]

After some debugging, these are my results:

• https://grpc.github.io/grpc/core/md_doc_compression.html

  • An ill-constructed message with its Compressed-Flag bit set but lacking a grpc-encoding entry different from identity in its metadata MUST fail with INTERNAL status

• grpc-3.2.4\lib\src\shared\message.dart

  • List frame(List rawPayload, [Codec? codec]) {}
  • when called with codec == IdentityCodec
    • header.setUint8(0, codec == null ? 0 : 1);
    • ^-- this is returning 1 (i.e. the compressed flag is set)
    • message-encoding is set to identity

This means the grpc message is ill-constructed. The correct condition should be

header.setUint8(0, (codec == null || codec.encodingName =="identity") ? 0 : 1);

[RubenGarcia]

Merge request fixing the issue. https://github.com/grpc/grpc-dart/pull/693