When you install a package manually via a .deb file it doesn't get updated by apt (see also the How does update work with programs installed from .deb file question), but what happens when you install a package that isn't available from the repositories for the current Ubuntu version, but gets included into a later Ubuntu version. When you upgrade to this new version that includes the package by default, will the system:

• Realize that the package is already installed and update it in the proper way.


• Realize that the package is already installed, but hold it on the manually installed version.


• Not realize that it is installed and install it again, causing the same package to be installed twice.


• Crash and burn in some other way?

If any of the later options is the correct answer, how do I prevent it?