[dev.link] all: merge branch 'master' into dev.linkdev.link

Clean merge.

Change-Id: Ia7b2808bc649790198d34c226a61d9e569084dc5

1 files changed, 31 insertions, 0 deletions

diff --git a/src/io/fs/stat.go b/src/io/fs/stat.go
new file mode 100644
index 0000000000..735a6e3281
--- /dev/null
+++ b/src/io/fs/stat.go
@@ -0,0 +1,31 @@
+// Copyright 2020 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.
+
+package fs
+
+// A StatFS is a file system with a Stat method.
+type StatFS interface {
+	FS
+
+	// Stat returns a FileInfo describing the file.
+	// If there is an error, it should be of type *PathError.
+	Stat(name string) (FileInfo, error)
+}
+
+// Stat returns a FileInfo describing the named file from the file system.
+//
+// If fs implements StatFS, Stat calls fs.Stat.
+// Otherwise, Stat opens the file to stat it.
+func Stat(fsys FS, name string) (FileInfo, error) {
+	if fsys, ok := fsys.(StatFS); ok {
+		return fsys.Stat(name)
+	}
+
+	file, err := fsys.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	return file.Stat()
+}