1 files changed, 42 insertions, 0 deletions
diff --git a/src/cmd/go/internal/renameio/umask_test.go b/src/cmd/go/internal/renameio/umask_test.go
new file mode 100644
index 0000000..65e4fa5
--- /dev/null
+++ b/src/cmd/go/internal/renameio/umask_test.go
@@ -0,0 +1,42 @@
+// Copyright 2019 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.
+
+// +build !plan9,!windows,!js
+
+package renameio
+
+import (
+	"io/fs"
+	"os"
+	"path/filepath"
+	"syscall"
+	"testing"
+)
+
+func TestWriteFileModeAppliesUmask(t *testing.T) {
+	dir, err := os.MkdirTemp("", "renameio")
+	if err != nil {
+		t.Fatalf("Failed to create temporary directory: %v", err)
+	}
+	defer os.RemoveAll(dir)
+
+	const mode = 0644
+	const umask = 0007
+	defer syscall.Umask(syscall.Umask(umask))
+
+	file := filepath.Join(dir, "testWrite")
+	err = WriteFile(file, []byte("go-build"), mode)
+	if err != nil {
+		t.Fatalf("Failed to write file: %v", err)
+	}
+
+	fi, err := os.Stat(file)
+	if err != nil {
+		t.Fatalf("Stat %q (looking for mode %#o): %s", file, mode, err)
+	}
+
+	if fi.Mode()&fs.ModePerm != 0640 {
+		t.Errorf("Stat %q: mode %#o want %#o", file, fi.Mode()&fs.ModePerm, 0640)
+	}
+}