cmd/go/internal/auth: use sync.OnceValues

Use sync.OnceValues (CL 451356, since Go 1.21) instead of sync.Once for cleaner code and less global variables, preventing their potential misuse. Change-Id: I9d7ccc42847fe77af1757672c31bb39e20007f92 Reviewed-on: https://go-review.googlesource.com/c/go/+/611016 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
aytanet · Sep 6, 2024 · ba2a16c · ba2a16c
1 parent e6ae2d8
commit ba2a16c
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Showing 2 changed files with 12 additions and 15 deletions.
diff --git a/src/cmd/go/internal/auth/auth.go b/src/cmd/go/internal/auth/auth.go
@@ -10,13 +10,17 @@ import "net/http"
 // AddCredentials fills in the user's credentials for req, if any.
 // The return value reports whether any matching credentials were found.
 func AddCredentials(req *http.Request) (added bool) {
+	netrc, _ := readNetrc()
+	if len(netrc) == 0 {
+		return false
+	}
+
 	host := req.Host
 	if host == "" {
 		host = req.URL.Hostname()
 	}
 
 	// TODO(golang.org/issue/26232): Support arbitrary user-provided credentials.
-	netrcOnce.Do(readNetrc)
 	for _, l := range netrc {
 		if l.machine == host {
 			req.SetBasicAuth(l.login, l.password)

diff --git a/src/cmd/go/internal/auth/netrc.go b/src/cmd/go/internal/auth/netrc.go
@@ -18,12 +18,6 @@ type netrcLine struct {
 	password string
 }
 
-var (
-	netrcOnce sync.Once
-	netrc     []netrcLine
-	netrcErr  error
-)
-
 func parseNetrc(data string) []netrcLine {
 	// See https://www.gnu.org/software/inetutils/manual/html_node/The-_002enetrc-file.html
 	// for documentation on the .netrc format.
@@ -91,20 +85,19 @@ func netrcPath() (string, error) {
 	return filepath.Join(dir, base), nil
 }
 
-func readNetrc() {
+var readNetrc = sync.OnceValues(func() ([]netrcLine, error) {
 	path, err := netrcPath()
 	if err != nil {
-		netrcErr = err
-		return
+		return nil, err
 	}
 
 	data, err := os.ReadFile(path)
 	if err != nil {
-		if !os.IsNotExist(err) {
-			netrcErr = err
+		if os.IsNotExist(err) {
+			err = nil
 		}
-		return
+		return nil, err
 	}
 
-	netrc = parseNetrc(string(data))
-}
+	return parseNetrc(string(data)), nil
+})