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>

diff --git a/src/cmd/go/internal/auth/auth.go b/src/cmd/go/internal/auth/auth.go
index 77edeb89245b7177c74986d0b9600f337f2c0813..b4ada4ef8be5a04a6ce2d3180d87a0f40cbd942e 100644 (file)
--- 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
index 0107f20d7a68ca9f2015583fdaf75cc1154bbfb8..f48dec1ab58d2055fd517921972736b1d318d1f7 100644 (file)
--- 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
+})