From 082a6a3a8b1835efccee8ec44ce37678b0ecb33e Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <iant@golang.org>
Date: Wed, 13 May 2015 12:54:11 -0700
Subject: [PATCH] unix: fix infinite recursion in itoa

Bring in http://golang.org/cl/138650044 from syscall package.

Change-Id: I554b0b31b981c682b6826644564971321a55c9e4
Reviewed-on: https://go-review.googlesource.com/10030
Reviewed-by: Rob Pike <r@golang.org>
---
 unix/export_test.go  |  7 +++++++
 unix/str.go          |  6 +++++-
 unix/syscall_test.go | 17 +++++++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)
 create mode 100644 unix/export_test.go

diff --git a/unix/export_test.go b/unix/export_test.go
new file mode 100644
index 00000000..570aa7ac
--- /dev/null
+++ b/unix/export_test.go
@@ -0,0 +1,7 @@
+// Copyright 2015 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+var Itoa = itoa
diff --git a/unix/str.go b/unix/str.go
index f873edec..35ed6643 100644
--- a/unix/str.go
+++ b/unix/str.go
@@ -8,8 +8,12 @@ package unix
 
 func itoa(val int) string { // do it here rather than with fmt to avoid dependency
 	if val < 0 {
-		return "-" + itoa(-val)
+		return "-" + uitoa(uint(-val))
 	}
+	return uitoa(uint(val))
+}
+
+func uitoa(val uint) string {
 	var buf [32]byte // big enough for int64
 	i := len(buf) - 1
 	for val >= 10 {
diff --git a/unix/syscall_test.go b/unix/syscall_test.go
index 9c57d9cd..95eac92a 100644
--- a/unix/syscall_test.go
+++ b/unix/syscall_test.go
@@ -7,6 +7,7 @@
 package unix_test
 
 import (
+	"fmt"
 	"testing"
 
 	"golang.org/x/sys/unix"
@@ -31,3 +32,19 @@ func TestEnv(t *testing.T) {
 	// make sure TESTENV gets set to "", not deleted
 	testSetGetenv(t, "TESTENV", "")
 }
+
+func TestItoa(t *testing.T) {
+	// Make most negative integer: 0x8000...
+	i := 1
+	for i<<1 != 0 {
+		i <<= 1
+	}
+	if i >= 0 {
+		t.Fatal("bad math")
+	}
+	s := unix.Itoa(i)
+	f := fmt.Sprint(i)
+	if s != f {
+		t.Fatalf("itoa(%d) = %s, want %s", i, s, f)
+	}
+}