os: avoid writing within the tree during testing CopyFS
Change-Id: I1d3e7c100ddfbd2ea9a7bb9e8efae89893c8365a
Reviewed-on: https://go-review.googlesource.com/c/go/+/566335
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Commit-Queue: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Andy Pan <panjf2000@gmail.com>