tests: add TestFileHoleCopy

Currently fails.

tests/plaintextnames/file_holes_test.go

@@ -0,0 +1,96 @@
+package plaintextnames
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"testing"
+
+	"github.com/rfjakob/gocryptfs/tests/test_helpers"
+
+	"github.com/rfjakob/gocryptfs/contrib/findholes/holes"
+)
+
+func findHolesPretty(t *testing.T, path string) string {
+	f, err := os.Open(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+
+	segments, err := holes.Find(int(f.Fd()))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	return holes.PrettyPrint(segments)
+}
+
+// TestFileHoleCopy creates a sparse times, copies it a few times, and check if
+// the copies are the same (including the location of holes and data sections).
+//
+// The test runs with -plaintextnames because that makes it easier to manipulate
+// cipherdir directly.
+func TestFileHoleCopy(t *testing.T) {
+	n := "TestFileHoleCopy"
+	pPath := []string{pDir + "/" + n}
+	cPath := []string{cDir + "/" + n}
+
+	f, err := os.Create(pPath[0])
+	if err != nil {
+		t.Fatal(err)
+	}
+	// | hole | x | hole | x | hole |
+	buf := []byte("x")
+	f.WriteAt(buf, 10000)
+	f.WriteAt(buf, 30000)
+	f.Truncate(50000)
+	f.Sync()
+	f.Close()
+
+	// You have to update this value manually when you change the sequence
+	// above
+	md5 := test_helpers.Md5fn(pPath[0])
+	if md5 != "4e8d0742bccfbcdbf1d71be688e4e81c" {
+		t.Fatalf("wrong md5: %s", md5)
+	}
+
+	pSegments := []string{findHolesPretty(t, pPath[0])}
+	cSegments := []string{findHolesPretty(t, cPath[0])}
+
+	for i := 1; i < 5; i++ {
+		pPath = append(pPath, fmt.Sprintf("%s.%d", pPath[0], i))
+		cPath = append(cPath, fmt.Sprintf("%s.%d", cPath[0], i))
+
+		out, err := exec.Command("cp", "--sparse=auto", pPath[i-1], pPath[i]).CombinedOutput()
+		if err != nil {
+			t.Fatal(string(out))
+		}
+
+		tmp := test_helpers.Md5fn(pPath[0])
+		if tmp != md5 {
+			t.Errorf("pPath[%d]: wrong md5, have %s, want %s", i, tmp, md5)
+		}
+
+		pSegments = append(pSegments, findHolesPretty(t, pPath[i]))
+		cSegments = append(cSegments, findHolesPretty(t, cPath[i]))
+	}
+
+	for i := range pSegments {
+		t.Logf("pSegments[%d]: %s", i, pSegments[i])
+		if i < len(pSegments)-1 {
+			if pSegments[i+1] != pSegments[i] {
+				t.Errorf("error: this is different than pSegments[%d]!", i+1)
+			}
+		}
+	}
+	t.Log("------------------------------------")
+	for i := range cSegments {
+		t.Logf("cSegments[%d]: %s", i, cSegments[i])
+		if i < len(pSegments)-1 {
+			if cSegments[i+1] != cSegments[i] {
+				t.Errorf("error: this is different than cSegments[%d]!", i+1)
+			}
+		}
+	}
+}