auto_upgrade! sometimes breaks has_and_belongs_to_many associations

[ibrahimtencer]

It seems that running auto_upgrade! can create problems for has_and_belongs_to_many associations. In particular, if you have a habtm association between groups and users, but then call ActiveRecord::Base.auto_upgrade!, this will change the groups_users table to have the columns "group_id" and "left_side_id" (which should be "user_id"). This makes the User#groups method fail.

I figured that ActiveRecord::Base.auto_upgrade! would update all tables. But it seems like this way won't work. So is there an easier way to update all tables, other than listing them manually and then calling auto_upgrade! on them? (If you do ActiveRecord::Base.descendants.each(&:auto_upgrade!) it creates the same error. I suppose this is because it was trying to update the association table itself?) This way of doing it seems fragile and prone to error (say, if you add a new table and forget to manually add it to the list).

A related question is whether there is a way to know which tables have "migrations pending", i.e. which haven't been auto_upgrade'd to a schema matching the model source code.