code review 6590047: pkg/syscall: Plan 9, 64-bit: Update error checks from s...

pkg/syscall: Plan 9, 64-bit: Update error checks from sys calls.

This change updates CL 6576057 for exceptional cases where
return values from Syscall/RawSyscall functions are used.

The system calls return 32-bit integers. With the recent change
in size of `int' in Go for amd64, the type conversion was not
catching `-1' return values. This change makes the conversion
explicitly `int32'.

[akumar, 2012-09-30 21:31:48]

Hello rsc@golang.org, r@golang.org (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[r, 2012-10-01 00:06:30]

LGTM

[r, 2012-10-01 00:09:26]

*** Submitted as http://code.google.com/p/go/source/detail?r=03190651924e ***

pkg/syscall: Plan 9, 64-bit: Update error checks from sys calls.

This change updates CL 6576057 for exceptional cases where
return values from Syscall/RawSyscall functions are used.

The system calls return 32-bit integers. With the recent change
in size of `int' in Go for amd64, the type conversion was not
catching `-1' return values. This change makes the conversion
explicitly `int32'.

R=rsc, r
CC=golang-dev
http://codereview.appspot.com/6590047

Committer: Rob Pike <r@golang.org>