net/http, net/http/httptest: locks being copied

[josharian]

From cmd/vet:

net/http/h2_bundle.go:5133: assignment copies lock value to *cfg: crypto/tls.Config contains sync.Once contains sync.Mutex
net/http/httptest/server.go:119: assignment copies lock value to *s.TLS: crypto/tls.Config contains sync.Once contains sync.Mutex

These seem like legitimate complaints.

It seems like tls.Config could use a Copy method, but probably not for Go 1.7.

cc @bradfitz @ianlancetaylor

[odeke-em]

Related to #15177?

[josharian]

Yes, probably. It's not obvious to me from the immediate context why these are ok, though.

If they are ok, they're yet more (new?) false positives...in which case, #16227 is related.

cc @valyala

[valyala]

Both cases look buggy, since they overwrite already existing mutex inside tls.Config with a new one.

[gopherbot]

CL https://golang.org/cl/28075 mentions this issue.

[bradfitz]

d24f446 did the first half, and https://go-review.googlesource.com/28344 is the http2 part, which will be bundled in to std before Go 1.8. Closing.

[gopherbot]

CL https://golang.org/cl/28344 mentions this issue.

[gopherbot]

CL https://golang.org/cl/29110 mentions this issue.