sync: document why copyChecker checks the condition twice
Fixes #40924
Change-Id: I249a278be1ec3c67088819af4456e6c393431724
Change-Id: I249a278be1ec3c67088819af4456e6c393431724
GitHub-Last-Rev:
772c7ae7e140ebd3896fc7786aae8b43ab3128c3
GitHub-Pull-Request: golang/go#61978
Reviewed-on: https://go-review.googlesource.com/c/go/+/518961
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Austin Clements <austin@google.com>
Auto-Submit: Austin Clements <austin@google.com>