unix: fix sendmsgN return value for empty iovecs and non-empty oob

Don't shadow the empty var when determining whether to send a single
byte when iovecs are empty but oob is non-empty. This will lead to the
n value correctly being reset to 0 before return.

No test because it's not possible to trigger this case on all platforms,
e.g. darwin where sendmsg with empty buf and non-empty oob returns
EINVAL.

This was introduced by CL 412497 and CL 419396.

Updates golang/go#52885

Change-Id: Iafc5a4b22e10b396ba5f7d4f2ac1c50df195a125
Reviewed-on: https://go-review.googlesource.com/c/sys/+/419914
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Florian Lehner <lehner.florian86@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
3 files changed
tree: 8e2b506da5ae9254a01936c85880478375f60792
  1. cpu/
  2. execabs/
  3. internal/
  4. plan9/
  5. unix/
  6. windows/
  7. .gitattributes
  8. .gitignore
  9. codereview.cfg
  10. CONTRIBUTING.md
  11. go.mod
  12. LICENSE
  13. PATENTS
  14. README.md
README.md

sys

Go Reference

This repository holds supplemental Go packages for low-level interactions with the operating system.

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The easiest way to install is to run go get -u golang.org/x/sys. You can also manually git clone the repository to $GOPATH/src/golang.org/x/sys.

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