gnome-terminal does not change window title after returning root account

If a user change user to root via sudo su command then exit root account by writing exit, gnome-terminal does not change window title or tab name to default one or profile's preferred title.

Steps to produce bug:
1- Open gnome-terminal -> title of the terminal shows user's preferred title like Terminal or user_name@host_name:some_dir_path
2- sudo su -> title or tab name of the terminal changes to root@host_name:some_dir_path
3- Exit root account by exit command
4- Title of the terminal remains root@host_name:some_dir_path

What I expect to happen:
1- Open gnome-terminal -> title of the terminal shows user's preferred title like Terminal or user_name@host_name:some_dir_path
2- sudo su -> title of the terminal changes to root@host_name:some_dir_path
3- Exit root account by exit command
4- Title of the terminal should change to user's preferred title like Terminal or user_name@host_name:some_dir_path

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: gnome-terminal 3.6.2-0ubuntu1
ProcVersionSignature: Ubuntu 3.16.0-24.32-generic 3.16.4
Uname: Linux 3.16.0-24-generic x86_64
ApportVersion: 2.14.7-0ubuntu8
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Nov 2 02:13:52 2014
InstallationDate: Installed on 2014-02-27 (247 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140224)
SourcePackage: gnome-terminal
UpgradeStatus: Upgraded to utopic on 2014-09-08 (54 days ago)