This makes me happy!

Revert "Added ActiveRecord::Base#last_modified to work with the new fresh_when/stale? conditional get methods from Action Pack"

Needless indirection with no added value.

This reverts commit 535853e8.

Added ActiveRecord::Base#last_modified to work with the new fresh_when/stale? conditional get methods from Action Pack

Add hackery to make Syck use encode_with/init_with. Fixes 1.8 after recent changes to attribute serialization.

Implement a mini state machine for serialized attributes. This means we
do not have to deserialize the values upon initialization, which means
that if we never actually access the attribute, we never have to
deserialize it.

This only existed to support methods like `set_table_name` in Active
Record, which are themselves being deprecated.

"Returns true if the specified attribute has been set by the user or by
a database load and is neither nil nor empty?"

Fixes #1613

'Type' is a reserved column for STI.  Changed conditions example to
avoid using that column name as an example.  The example isn't
STI-related (and mentioning STI here is needless clutter), so changing
to avoid accidentally encouraging users to use 'type' as a column name
for other purposes.

This reverts commit ee2be435.

If we don't have a primary key when we ask for it, it's better to fail
fast. Fixes GH #2307.

Closes #2807.

For consistency with find_or_initialize_by. Also remove first_or_build
alias.

This fixes a situation I encountered where a subclass would cache the
name of a generated attribute method in @_defined_class_methods. Then,
when the superclass has it's attribute methods undefined, the subclass
would always have to dispatch through method_missing, because the
presence of the attribute in @_defined_class_methods would mean that it
is never generated again, even if undefine_attribute_methods is called
on the subclass.

There various other confusing edge cases like this. STI classes share
columns, so let's just keep all the attribute method generation state
isolated to the base class.

This let's you write things like:

    User.where(:first_name => "Scarlett").first_or_create!(:last_name => "Johansson", :hot => true)

Related to #2420.

In 1efd8828, ConnectionAdapters was put under eager_autoload. Due to the requires in that file, this caused ConnectionSpecification to be loaded, which references ActiveRecord::Base, which means the database connection is established. We do not want to connect to the database when Active Record is loaded, only when ActiveRecord::Base is first referenced by the user.

Reason: The hash form is secure, and preferred over the array form if possible.

This reverts commit 6dc74959.

Make it the responsibility of the connection to hold onto an ARel visitor for generating SQL. This improves the code architecture generally, and solves some problems with marshalling. Adapter authors please take note: you now need to define an Adapter.visitor_for method, but it degrades gracefully with a deprecation warning for now.

Reason: The hash form is secure, and preferred over the array form if possible.

This reverts commit 6dc74959.