Comment 2 for bug 1681070

When you attempt to install from the live environment over an existing installation, the installer will detect that installation and allow you to perform an upgrade. It works just like the upgrade process in Ubuntu -- except the MATE installer clobbers the existing /etc/passwd file and creates and prompts you to create a new user account. When performing the same process in Ubuntu in both current and previous releases, the installer skips the user account creation prompts and retains the existing user accounts.