tests: add TestSeekDir

Acc. to the commit message,
https://github.com/hanwen/go-fuse/commit/0d1228a39dd49c83c8b7c30dec7928f5d7d84cc0
break seeking in directories. This commit appears in go-fuse v2.6.0.

1 files changed, 49 insertions, 0 deletions

diff --git a/tests/defaults/main_test.go b/tests/defaults/main_test.go
index d0210e2..1cc7cb6 100644
--- a/tests/defaults/main_test.go
+++ b/tests/defaults/main_test.go
@@ -3,6 +3,7 @@ package defaults
 
 import (
 	"bytes"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
@@ -506,3 +507,51 @@ func TestForceOwner(t *testing.T) {
 		t.Errorf("LOOKUP returned uid or gid != 1234: %#v", st)
 	}
 }
+
+func TestSeekDir(t *testing.T) {
+	wd := test_helpers.DefaultPlainDir + "/" + t.Name()
+	err := os.Mkdir(wd, 0700)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for i := 0; i < 10; i++ {
+		path := fmt.Sprintf(wd+"/%3d", i)
+		err = os.WriteFile(path, nil, 0600)
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	fd, err := syscall.Open(wd, syscall.O_DIRECTORY|syscall.O_RDONLY, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer syscall.Close(fd)
+
+	buf := make([]byte, 1000)
+	n, err := unix.Getdents(fd, buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("1st getdents returned %d bytes", n)
+
+	n, err = unix.Getdents(fd, buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("2nd getdents returned %d bytes", n)
+
+	_, err = unix.Seek(fd, 0, 0)
+	if err != nil {
+		t.Error(err)
+	}
+
+	n, err = unix.Getdents(fd, buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("3rd getdents (after seek) returned %d bytes", n)
+	if n == 0 {
+		t.Error("Seek did not have any effect")
+	}
+}