Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

1.7.4 or current master.

What operating system and processor architecture are you using (go env)?

Linux, Mac, all.

What did you do?

I observed that http.Transport.RoundTrip and http.NewRequest use the validMethod function to validate that the request's method is syntactically valid, but http.Server does not. This is different behavior than, say, the validation of header names which is done in both directions.

(I specifically noticed this because it's a mechanism by which straightforward use of httputil.ReverseProxy can lead to an error in RoundTripping the request which is the fault of the original client, not the backend server.)

@bradfitz agreed with me that this is a bug and asked me to file it.

See https://play.golang.org/p/DUHElpDb-u

What did you expect to see?

I expected http.Server to have the same validation as http.NewRequest and http.Transport.RoundTrip and reject incoming requests with Method GE)T before getting to the handler.

What did you see instead?

In the playground you can see that the handler is invoked with Method GE)T.