associations and nested_attributes internals... looking for patch guidance

Hello,

I ran into something that works in Rails 3.0.x, but no longer works in
Rails 3.1.x and it seems to be valid usage and I was wondering if
somebody more familiar with the activerecord internals could point me
in the right direction...

Here's my basic use case using nested attributes:

project = Project.find 1
params[:task] = {:name => 'task', :project_attributes => {'1' =>
{:name => 'project'}}}

# this works in rails 3.0.11 (the project name is assigned correclty)
# this does not work in rails 3.1.3
project.tasks.new params[:task]

# this works in rails 3.1.3
# even though we're creating the new task from the relation owned by
the project object, we need to pass the project id in explicitly so
that it updates correctly
project.tasks.new params[:task].merge(:project_id => project.id)

There has been a lot of refactoring of active record between Rails 3.0
and 3.1, so I'm a bit lost in the current code, but I've found the
main culprit to be in nested_attributes.rb
https://github.com/rails/rails/blob/master/activerecord/lib/active_record/nested_attributes.rb#L327

The line with:
record = send(association_name)

... that correctly returns the project record in Rails 3.0, but it's nil in 3.1.

I've traced (I think) the origination of this issue in Rails 3.1 to
https://github.com/rails/rails/blob/master/activerecord/lib/active_record/associations/association.rb#L233
When building the association (the "owner" value in this scope has the
valid project) we lose reference to the project owner value which we
would need to successfully assign the nested attributes.

I'll provide a patch for this issue, but I feel I'm missing something
simple here on how to assign the owner of that association before it
tries to assign the nested attributes. If somebody can point me in
the right direction, I'll work on a patch.

Thanks

3 weeks later (got busy), here's my patch...

https://github.com/rails/rails/pull/3991