Sending messages to yourself

What I expected to happen was...:
seeing a warn regarding to not being able to send messages to yourself

What actually happened was...:
(suppose my username is Steve)

You whisper to Steve: Hello

Steve whispers to you: Hello

Steps to Reproduce:

1. join a Minecraft single player mode
2. press T then type the command below (suppose your username is "Steve")

3. /tell Steve Hello (you can type whatever instead of "Hello")
4. you will see the following result

5. You whisper to Steve: Hello

6. Steve whispers to you: Hello