net/http: "Read ""; want Hello" failure

[aclements]

Commit 9025408 introduced TestCancelRequestMidBody_h2 in net/http, which is failing frequently on linux-amd64-noopt with:

--- FAIL: TestCancelRequestMidBody_h2 (0.00s)
    clientserver_test.go:452: Read ""; want Hello
FAIL
FAIL    net/http    11.721s

Current failures:

$ greplogs -l -md -dashboard -e 'Read ""; want Hello'
2015-12-15T00:43:53-9025408/linux-amd64-noopt
2015-12-15T04:48:33-9b1068a/linux-amd64-noopt
2015-12-15T06:43:35-3540376/linux-amd64-noopt
2015-12-15T16:15:38-6383fb6/linux-amd64-noopt
2015-12-15T16:15:59-4ad64ca/linux-amd64-noopt
2015-12-15T16:16:08-87d939d/linux-amd64-noopt

@rakyll @bradfitz

[bradfitz]

This is very bizarre.

I don't expect any flakiness out of that test, and I don't see it anywhere else (or on my machine with even 1000+ iterations).

Can I blame the noopt code generation or something?

[bradfitz]

Sent https://go-review.googlesource.com/17825

[gopherbot]

CL https://golang.org/cl/17825 mentions this issue.