libgo: update to Go1.16 release

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/293793

3 files changed, 78 insertions, 1 deletions

diff --git a/libgo/go/os/file.go b/libgo/go/os/file.go
index 416bc0e..52dd943 100644
--- a/libgo/go/os/file.go
+++ b/libgo/go/os/file.go
@@ -620,10 +620,21 @@ func DirFS(dir string) fs.FS {
 	return dirFS(dir)
 }
 
+func containsAny(s, chars string) bool {
+	for i := 0; i < len(s); i++ {
+		for j := 0; j < len(chars); j++ {
+			if s[i] == chars[j] {
+				return true
+			}
+		}
+	}
+	return false
+}
+
 type dirFS string
 
 func (dir dirFS) Open(name string) (fs.File, error) {
-	if !fs.ValidPath(name) {
+	if !fs.ValidPath(name) || runtime.GOOS == "windows" && containsAny(name, `\:`) {
 		return nil, &PathError{Op: "open", Path: name, Err: ErrInvalid}
 	}
 	f, err := Open(string(dir) + "/" + name)
diff --git a/libgo/go/os/os_test.go b/libgo/go/os/os_test.go
index 40ba056..734c655 100644
--- a/libgo/go/os/os_test.go
+++ b/libgo/go/os/os_test.go
@@ -2721,6 +2721,40 @@ func TestDirFS(t *testing.T) {
 	if err := fstest.TestFS(DirFS("./testdata/dirfs"), "a", "b", "dir/x"); err != nil {
 		t.Fatal(err)
 	}
+
+	// Test that Open does not accept backslash as separator.
+	d := DirFS(".")
+	_, err := d.Open(`testdata\dirfs`)
+	if err == nil {
+		t.Fatalf(`Open testdata\dirfs succeeded`)
+	}
+}
+
+func TestDirFSPathsValid(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skipf("skipping on Windows")
+	}
+
+	d := t.TempDir()
+	if err := os.WriteFile(filepath.Join(d, "control.txt"), []byte(string("Hello, world!")), 0644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(d, `e:xperi\ment.txt`), []byte(string("Hello, colon and backslash!")), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	fsys := os.DirFS(d)
+	err := fs.WalkDir(fsys, ".", func(path string, e fs.DirEntry, err error) error {
+		if fs.ValidPath(e.Name()) {
+			t.Logf("%q ok", e.Name())
+		} else {
+			t.Errorf("%q INVALID", e.Name())
+		}
+		return nil
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
 }
 
 func TestReadFileProc(t *testing.T) {
diff --git a/libgo/go/os/readfrom_linux_test.go b/libgo/go/os/readfrom_linux_test.go
index 3704717..1d145da 100644
--- a/libgo/go/os/readfrom_linux_test.go
+++ b/libgo/go/os/readfrom_linux_test.go
@@ -361,3 +361,35 @@ func (h *copyFileRangeHook) install() {
 func (h *copyFileRangeHook) uninstall() {
 	*PollCopyFileRangeP = h.original
 }
+
+// On some kernels copy_file_range fails on files in /proc.
+func TestProcCopy(t *testing.T) {
+	const cmdlineFile = "/proc/self/cmdline"
+	cmdline, err := os.ReadFile(cmdlineFile)
+	if err != nil {
+		t.Skipf("can't read /proc file: %v", err)
+	}
+	in, err := os.Open(cmdlineFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer in.Close()
+	outFile := filepath.Join(t.TempDir(), "cmdline")
+	out, err := os.Create(outFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := io.Copy(out, in); err != nil {
+		t.Fatal(err)
+	}
+	if err := out.Close(); err != nil {
+		t.Fatal(err)
+	}
+	copy, err := os.ReadFile(outFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(cmdline, copy) {
+		t.Errorf("copy of %q got %q want %q\n", cmdlineFile, copy, cmdline)
+	}
+}