Add an :update_only option to accepts_nested_attributes_for for to-one associations. [#2563 state:resolved]
Signed-off-by: NEloy Duran <eloy.de.enige@gmail.com>

This makes sure that, in a HABTM association, only one join record is craeted.

Make polymorphic_inverse_of in Reflection throw an InverseOfAssociationNotFoundError if the supplied class doesn't have the appropriate association. [#3520 state:resolved]
Signed-off-by: NEloy Duran <eloy.de.enige@gmail.com>

Provide a slightly more robust we_can_set_the_inverse_on_this? method for polymorphic belongs_to associations. [#3520 state:resolved]

Also add a new test for polymorphic belongs_to that test direct accessor assignment, not just .replace assignment.
Signed-off-by: NEloy Duran <eloy.de.enige@gmail.com>

Signed-off-by: NEloy Duran <eloy.de.enige@gmail.com>

Get rid of a duplicate set_inverse_instance call if you use new_record(true) (e.g. you want to replace the existing instance).
Signed-off-by: NEloy Duran <eloy.de.enige@gmail.com>

Signed-off-by: NEloy Duran <eloy.de.enige@gmail.com>

Remove ActiveRecord runtime logging from ActionPack and place in ActiveRecord, adding it through config.action_controller.include hook.