Support single-step upgrading from any version to current version

[jernst]

Upgrading while skipping a major package version currently is a lot of manual work. ("Download; install; upgrade; uninstall; repeat" per forum post.) This should be automated.

Many users have run into this, as the many duplicate bug reports related to "Exception: Updates between multiple major versions and downgrades are unsupported." show.

Mediawiki has one way of doing this kind of thing. At every release, they add whatever migrations needed to be done at the end of a long upgrade script, which grows with every release. As a result, the script can upgrade any old version of Mediawiki and installs of intermediate versions are never required.

This is important not just for people who don't upgrade ownCloud every time a new version comes out, but particularly for being able to restore old backups.

We just ran into this issue on UBOS where users may end up with partially non-functioning devices as we cannot invoke any code (unless we develop it ourselves) that migrates and will work for all possible ownCloud installs. See also uboslinux/ubos-app-owncloud#9.

(I just added this here because lots of the reports point to #4, there may be a better place where to file this.)

[karlitschek]

I assume that you are talking about ownCloud upgrades and not upgrades of ownCloud apps?
If this is the case then this is the wrong repo. This is a core issue but also a duplicate.

[jernst]

Moved to owncloud/core#21859