NameConflictBehavior Fail not working

[shiroychoksey]

I'm trying to Fail when a name conflict occurs, but it's not working - I can run this code as many times as I like and never get an error...

                using (FileStream fs = new FileStream("food.txt", FileMode.Open, FileAccess.Read, FileShare.Read))
                {
                    ODItemReference od = new ODItemReference() { Path = "/drive/root:" };

                    ODItem rf = await cn.PutNewFileToParentItemAsync(od, "food.txt", fs, 
                        new ItemUploadOptions() { NameConflict = NameConflictBehavior.Fail });

                    ODItem rf3 = await cn.UploadLargeFileAsync(new ODItemReference() { Path = od.Path + "/food.txt" }, fs,
                        new ItemUploadOptions() { NameConflict = NameConflictBehavior.Fail });

                }