I'm packaging Bugzilla but at now I don't know how to make downgrade possible.
After installing the last package version (not public at now), it will not be possible to downgrade while there is major change in the data structure. I've try to resolve some by making the prerm script change back the data structure, but after all there were left some inconsistency. For example on last Bugzilla cvs version clear password have squeeze out, so you imaging in what trouble we are if we downgrade after that! In this case I have a solution, that is, regenerate random password for all user. But I think this is only the visible part of the iceberg, and indeed, that breaks other where. The mainstream is very active, so for upgrade they maintain a script to update database structure. As I call this script in postinst upgrade work well. Unfortunately this script isn't done for downgrade. It would be very boring to closely fallow upstream change and make prerm trying to regenerate old database structure, at least on CVS snapshot. So how to deal with this? Rémi Perrot
