Add failing test that triggers the stack overflow for #2578.

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

Author: bryanstearns

activerecord/test/cases/autosave_association_test.rb

@@ -3,6 +3,8 @@
 require 'models/company'
 require 'models/customer'
 require 'models/developer'
+require 'models/invoice'
+require 'models/line_item'
 require 'models/order'
 require 'models/parrot'
 require 'models/person'
@@ -1169,3 +1171,10 @@ def setup
     assert !@pirate.respond_to?(:validate_associated_records_for_non_validated_parrots)
   end
 end
+
+class TestAutosaveAssociationWithTouch < ActiveRecord::TestCase
+  def test_autosave_with_touch_should_not_raise_system_stack_error
+    invoice = Invoice.create
+    assert_nothing_raised { invoice.line_items.create(:amount => 10) }
+  end
+end

activerecord/test/models/invoice.rb

@@ -0,0 +1,4 @@
+class Invoice < ActiveRecord::Base
+  has_many :line_items, :autosave => true
+  before_save {|record| record.balance = record.line_items.map(&:amount).sum }
+end

activerecord/test/models/line_item.rb

@@ -0,0 +1,3 @@
+class LineItem < ActiveRecord::Base
+  belongs_to :invoice, :touch => true
+end

activerecord/test/schema/schema.rb

@@ -192,6 +192,11 @@ def create_table(*args, &block)
     t.string :info
   end
 
+  create_table :invoices, :force => true do |t|
+    t.integer :balance
+    t.datetime :updated_at
+  end
+
   create_table :items, :force => true do |t|
     t.column :name, :integer
   end
@@ -217,6 +222,11 @@ def create_table(*args, &block)
     t.integer :version, :null => false, :default => 0
   end
 
+  create_table :line_items, :force => true do |t|
+    t.integer :invoice_id
+    t.integer :amount
+  end
+
   create_table :lock_without_defaults, :force => true do |t|
     t.column :lock_version, :integer
   end