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@@ -63,7 +63,7 @@ module ActiveRecord
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             #{scope_condition_method}
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-            after_destroy  :remove_from_list
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+            before_destroy :remove_from_list
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             before_create  :add_to_list_bottom
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           EOV
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         end
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@@ -121,7 +121,10 @@ module ActiveRecord
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         # Removes the item from the list.
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         def remove_from_list
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-          decrement_positions_on_lower_items if in_list?
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+          if in_list?
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+            decrement_positions_on_lower_items
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+            update_attribute position_column, nil
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+          end
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         end
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         # Increase the position of this item without adjusting the rest of the list.

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@@ -211,6 +211,53 @@ class ListTest < Test::Unit::TestCase
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     assert_equal [new2, new1, new3], ListMixin.find(:all, :conditions => 'parent_id IS NULL', :order => 'pos')
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   end
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+  def test_remove_from_list_should_then_fail_in_list?
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+    assert_equal true, mixins(:list_1).in_list?
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+    mixins(:list_1).remove_from_list
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+    assert_equal false, mixins(:list_1).in_list?
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+  end
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+
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+  def test_remove_from_list_should_set_position_to_nil
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+    assert_equal [mixins(:list_1),
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+                  mixins(:list_2),
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+                  mixins(:list_3),
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+                  mixins(:list_4)],
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+                  ListMixin.find(:all, :conditions => 'parent_id = 5', :order => 'pos')
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+
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+    mixins(:list_2).remove_from_list
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+
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+    assert_equal [mixins(:list_2, :reload),
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+                  mixins(:list_1, :reload),
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+                  mixins(:list_3, :reload),
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+                  mixins(:list_4, :reload)],
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+                  ListMixin.find(:all, :conditions => 'parent_id = 5', :order => 'pos')
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+
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+    assert_equal 1, mixins(:list_1).pos
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+    assert_equal nil, mixins(:list_2).pos
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+    assert_equal 2, mixins(:list_3).pos
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+    assert_equal 3, mixins(:list_4).pos
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+  end
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+
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+  def test_remove_before_destroy_does_not_shift_lower_items_twice
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+    assert_equal [mixins(:list_1),
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+                  mixins(:list_2),
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+                  mixins(:list_3),
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+                  mixins(:list_4)],
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+                  ListMixin.find(:all, :conditions => 'parent_id = 5', :order => 'pos')
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+
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+    mixins(:list_2).remove_from_list
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+    mixins(:list_2).destroy
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+
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+  assert_equal [mixins(:list_1, :reload),
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+                mixins(:list_3, :reload),
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+                mixins(:list_4, :reload)],
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+                  ListMixin.find(:all, :conditions => 'parent_id = 5', :order => 'pos')
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+
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+    assert_equal 1, mixins(:list_1).pos
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+    assert_equal 2, mixins(:list_3).pos
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+    assert_equal 3, mixins(:list_4).pos
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+  end
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+
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 end
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 class TreeTest < Test::Unit::TestCase