From 198b2e1b5a7f46a5c3a804c89bf5676878ea7561 Mon Sep 17 00:00:00 2001
From: Quim Muntal <quimmuntal@gmail.com>
Date: Fri, 9 Aug 2024 18:17:57 +0000
Subject: [PATCH] Revert "os/user: speed up Current on Windows"

This reverts CL 597255.

Reason for revert: Broke windows/arm64

Fixes #68822.
Updates #68312.

Change-Id: I43efabad43c74045888bb62bd27522aeaba0a64c
Reviewed-on: https://go-review.googlesource.com/c/go/+/604555
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
---
 .../syscall/windows/security_windows.go       | 19 -------------------
 src/os/user/lookup_windows.go                 | 16 +++-------------
 src/os/user/user_test.go                      |  3 +--
 3 files changed, 4 insertions(+), 34 deletions(-)

diff --git a/src/internal/syscall/windows/security_windows.go b/src/internal/syscall/windows/security_windows.go
index e528744caa..95694c368a 100644
--- a/src/internal/syscall/windows/security_windows.go
+++ b/src/internal/syscall/windows/security_windows.go
@@ -156,22 +156,3 @@ type UserInfo4 struct {
 //
 //go:linkname GetSystemDirectory
 func GetSystemDirectory() string // Implemented in runtime package.
-
-// GetUserName retrieves the user name of the current thread
-// in the specified format.
-func GetUserName(format uint32) (string, error) {
-	n := uint32(50)
-	for {
-		b := make([]uint16, n)
-		e := syscall.GetUserNameEx(format, &b[0], &n)
-		if e == nil {
-			return syscall.UTF16ToString(b[:n]), nil
-		}
-		if e != syscall.ERROR_MORE_DATA {
-			return "", e
-		}
-		if n <= uint32(len(b)) {
-			return "", e
-		}
-	}
-}
diff --git a/src/os/user/lookup_windows.go b/src/os/user/lookup_windows.go
index c319324d11..f259269a53 100644
--- a/src/os/user/lookup_windows.go
+++ b/src/os/user/lookup_windows.go
@@ -232,22 +232,12 @@ func current() (*User, error) {
 		if e != nil {
 			return e
 		}
-		username, e := windows.GetUserName(syscall.NameSamCompatible)
+		username, domain, e := lookupUsernameAndDomain(u.User.Sid)
 		if e != nil {
 			return e
 		}
-		displayName, e := windows.GetUserName(syscall.NameDisplay)
-		if e != nil {
-			return e
-		}
-		usr = &User{
-			Uid:      uid,
-			Gid:      gid,
-			Username: username,
-			Name:     displayName,
-			HomeDir:  dir,
-		}
-		return nil
+		usr, e = newUser(uid, gid, dir, username, domain)
+		return e
 	})
 	return usr, err
 }
diff --git a/src/os/user/user_test.go b/src/os/user/user_test.go
index 31486aed03..fa597b78ec 100644
--- a/src/os/user/user_test.go
+++ b/src/os/user/user_test.go
@@ -45,9 +45,8 @@ func TestCurrent(t *testing.T) {
 }
 
 func BenchmarkCurrent(b *testing.B) {
-	// Benchmark current instead of Current because Current caches the result.
 	for i := 0; i < b.N; i++ {
-		current()
+		Current()
 	}
 }
 
-- 
2.48.1