[#665] Prevent ContinuationToken duplication in ListObjectsV2 result

Signed-off-by: Aleksey Kravchenko <al.kravchenko@yadro.com>

api/handler/object_list_test.go

@@ -938,6 +938,29 @@ func TestPeriodicWriter(t *testing.T) {
 	})
 }
 
+func TestListObjectsNotDuplicateContinuationToken(t *testing.T) {
+	tc := prepareHandlerContext(t)
+
+	bktName := "bucket-for-listing"
+	bktInfo := createTestBucket(tc, bktName)
+
+	for _, name := range []string{"bar /baz", "bar baz/foo", "bar/baz"} {
+		createTestObject(tc, bktInfo, name, encryption.Params{})
+	}
+
+	t.Run("list v2", func(t *testing.T) {
+		res1 := listObjectsV2(tc, bktName, "", "", "", "", 1)
+		res2 := listObjectsV2(tc, bktName, "", "", "", res1.NextContinuationToken, 1)
+		require.NotEqual(t, res1.NextContinuationToken, res2.NextContinuationToken)
+	})
+
+	t.Run("list versions", func(t *testing.T) {
+		res1 := listObjectsVersions(tc, bktName, "", "", "", "", 1)
+		res2 := listObjectsVersions(tc, bktName, "", "", res1.NextKeyMarker, res1.NextVersionIDMarker, 1)
+		require.NotEqual(t, res1.NextVersionIDMarker, res2.NextVersionIDMarker)
+	})
+}
+
 func checkVersionsNames(t *testing.T, versions *ListObjectsVersionsResponse, names []string) {
 	for i, v := range versions.Version {
 		require.Equal(t, names[i], v.Key)