net/http: optimize http2 in readPreface phase

[detailyang]

[gopherbot]

Change https://golang.org/cl/187457 mentions this issue: x/net/http2: zero allocate in readPreface

[av86743]

That's some negation:

		} else if string(buf[0:8]) != "PRI * HT" &&
			string(buf[8:16]) != "TP/2.0\r\n" &&
			string(buf[16:24]) != "\r\nSM\r\n\r\n" {

[FiloSottile]

@av86743 Please use Gerrit for code review, so authors and future reviewers can track comments associated with revisions.

[av86743]

@av86743 Please use Gerrit for code review, so authors and future reviewers can track comments associated with revisions.

Why would I?

[bradfitz]

On https://go-review.googlesource.com/c/net/+/187457 I said:

Sorry, this isn't something that happens enough to be worth optimizing, especially not at this readability/complexity cost.