How to update Leap?
Leap gets bugs fixed and security updates regularly. To apply official maintenance updates, run the following command as root (ideally inside a screen or tmux session):
zypper patch will only apply packages listed on patchinfo files.
Sometimes third party repositories also offer updates of packages that are not maintenance updates. To install package updates that are not maintenance updates run the following command as root (ideally inside a screen or tmux session):
Graphical applications for updating the system are also available, See for example: System Updates
Don't confuse zypper update, which only upgrades already installed packages, with zypper dist-upgrade, which also installs and removes packages, as it tries to perform a distribution upgrade.
When a new Leap version gets released, a distribution upgrade is needed. See: SDB:System upgrade