Allow client to disable sending of trailers by omitting "TE" header.

[johanbrandhorst]

🐛 Bug Report

We shouldn't send trailers unless the client sends the "TE" trailer.

See #1697 for more context

[anthonydevelops]

@johanbrandhorst can I take on this issue?

[johanbrandhorst]

Absolutely! Please do.

[anthonydevelops]

@johanbrandhorst Seems someone has begun working on this already with a draft PR, so I'll go ahead and un-assign myself for now. Thanks for the opportunity though! I'll try tackling the next one I feel confident enough to do. 👍

[johanbrandhorst]

I think #1709 is actually trying to solve #1697, so this one is still up for grabs!

[ghost]

Edit (swapped mistake for tip):
Maybe this will help (https://github.com/grpc-ecosystem/grpc-gateway/blob/master/runtime/errors.go#L158-179 )

[johanbrandhorst]

The handling of the "TE" trailer is only present in the error handler, not the normal path (see https://github.com/grpc-ecosystem/grpc-gateway/blob/v2/runtime/handler.go#L166). I'm not sure what you're trying to say but you're not fixing this case in your PR.

[ghost]

@johanbrandhorst My mistake.
Comment has been edited.