Bug#993287: "apt-get install" doesn't preserve autoinstall status of upgraded packages

[Esa Peuha]

Package: apt
Version: 2.3.8

The man page for apt-get states that the command to upgrade a specific
package is "apt-get install". Therefore, if "apt-get install foo" does
upgrade package foo which has been marked as automatically installed,
I would expect foo's autoinstall status to be preserved, and this is
what has happened until recently. However, since apt 2.3.3 foo will be
marked as manually installed, which seems to be an unintended change.