From 85bd1af33183918fd38eee1c29ceeda12532c446 Mon Sep 17 00:00:00 2001
From: Evan Jones <ej@evanjones.ca>
Date: Tue, 17 Oct 2023 09:01:31 -0400
Subject: [PATCH] osutil: remove unused Unsetenv function

The osutil.Unsetenv function is not used. Today, os.Unsetenv exists
in the standard library, and is already used elsewhere in etcd.
Removing this function could break things that may be importing this
package. According to pkg.go.dev, it seems like the only thing is
etcd forks, so it may be worth getting rid of this code. See:

https://pkg.go.dev/github.com/coreos/etcd/pkg/osutil?tab=importedby

Signed-off-by: Evan Jones <ej@evanjones.ca>
---
 pkg/osutil/osutil.go      | 20 --------------------
 pkg/osutil/osutil_test.go | 25 -------------------------
 2 files changed, 45 deletions(-)

diff --git a/pkg/osutil/osutil.go b/pkg/osutil/osutil.go
index cbf96e2e0..c1405db70 100644
--- a/pkg/osutil/osutil.go
+++ b/pkg/osutil/osutil.go
@@ -15,27 +15,7 @@
 // Package osutil implements operating system-related utility functions.
 package osutil
 
-import (
-	"os"
-	"strings"
-)
-
 var (
 	// support to override setting SIG_DFL so tests don't terminate early
 	setDflSignal = dflSignal
 )
-
-func Unsetenv(key string) error {
-	envs := os.Environ()
-	os.Clearenv()
-	for _, e := range envs {
-		strs := strings.SplitN(e, "=", 2)
-		if strs[0] == key {
-			continue
-		}
-		if err := os.Setenv(strs[0], strs[1]); err != nil {
-			return err
-		}
-	}
-	return nil
-}
diff --git a/pkg/osutil/osutil_test.go b/pkg/osutil/osutil_test.go
index 322d2770c..28fcc7288 100644
--- a/pkg/osutil/osutil_test.go
+++ b/pkg/osutil/osutil_test.go
@@ -17,7 +17,6 @@ package osutil
 import (
 	"os"
 	"os/signal"
-	"reflect"
 	"syscall"
 	"testing"
 	"time"
@@ -27,30 +26,6 @@ import (
 
 func init() { setDflSignal = func(syscall.Signal) {} }
 
-func TestUnsetenv(t *testing.T) {
-	tests := []string{
-		"data",
-		"space data",
-		"equal=data",
-	}
-	for i, tt := range tests {
-		key := "ETCD_UNSETENV_TEST"
-		if os.Getenv(key) != "" {
-			t.Fatalf("#%d: cannot get empty %s", i, key)
-		}
-		env := os.Environ()
-		if err := os.Setenv(key, tt); err != nil {
-			t.Fatalf("#%d: cannot set %s: %v", i, key, err)
-		}
-		if err := Unsetenv(key); err != nil {
-			t.Errorf("#%d: unsetenv %s error: %v", i, key, err)
-		}
-		if g := os.Environ(); !reflect.DeepEqual(g, env) {
-			t.Errorf("#%d: env = %+v, want %+v", i, g, env)
-		}
-	}
-}
-
 func waitSig(t *testing.T, c <-chan os.Signal, sig os.Signal) {
 	select {
 	case s := <-c: