rails/rails — pull request #7548 by ernie (2012-09-06 19:46:10+00:00)
Title: Raise MissingAttributeError on query methods

When calling a query method on an attribute that was note selected by
an ActiveRecord query, an ActiveModel::MissingAttributeError is not
raised. Instead, a nil value is returned, which will return false once
cast to boolean.

This is undesirable, as we should not give the impression that we know
the attribute's boolean value when we haven't loaded the attribute's
(possibly) non-boolean value from the database.

This issue is present on versions going back as far as 2.3, at least.