Missing columns in _versions table cause error

[drothlis]

acts_as_versioned should determine which columns to version, based on the #{model}_versions table.

The documentation for ActiveRecord::Acts::Versioned::ClassMethods#acts_as_versioned says:

The _versions table should contain all the fields you want versioned

but this is clearly not the case (with version 0.5.2). For any attributes missing in the _versions table, I get:

undefined method attribute=' for #Model::Version:0x180dfe4 vendor/acts_as_versioned/lib/acts_as_versioned.rb:331:in send'
vendor/acts_as_versioned/lib/acts_as_versioned.rb:331:in clone_versioned_model' vendor/acts_as_versioned/lib/acts_as_versioned.rb:330:in each'
vendor/acts_as_versioned/lib/acts_as_versioned.rb:330:in clone_versioned_model' vendor/acts_as_versioned/lib/acts_as_versioned.rb:273:in save_version'

[technoweenie]

You can add missing columns to non_versioned_columns, also in the documentation. Automatic column detection like you've described would be nice if someone has a patch.