Followup: ReadHandler should return a 'malformed message' on invalid data version filter

[yunhanw-google]

Followup: This seems pretty broken in that we will return a generic Failure here on the IM level instead of a useful "malformed message" error code.

This problem is not new with this PR, but please make sure there is an issue filed tracking it.

Originally posted by @bzbarsky-apple in #14711 (comment)

[mrjerryjohns]

Is this really a spec issue? I don't see mention in the spec of the specific error that needs to be returned here...

[bzbarsky-apple]

@mrjerryjohns Spec generally says that if action fields are invalid you return InvalidAction, no?

[mrjerryjohns]

@yunhanw-google can you tackle this as well? It's in line with the other PR you already have in this space (#19356).

[yunhanw-google]

yes

[andy31415]

Is this required for v1.0? It looks like unfriendly message, however unsure about the "spec 1.0" tags. Is this a spec failure?

[bzbarsky-apple]

Is this a spec failure?

Technically, yes. The spec defines what error code should be returned here, and we are returning the wrong one.

The "unfriendly message" is just a consequence of how the error code gets logged by the other side, but the wrong error code is the spec issue.

[bzbarsky-apple]

This got fixed in #21374 as far as I can tell.