Merge pull request #11306 from jetthoughts/11288_remove_extra_queries_for_belongs_to_with_touch

 #11288: Removed duplicated touching

Conflicts:
	activerecord/CHANGELOG.md

3 files changed, 50 insertions, 2 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index f59f79112e..1eb2f2d130 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,10 @@
+*   Remove extra select and update queries on save/touch/destroy ActiveRecord model
+    with belongs to reflection with option `touch: true`.
+
+    Fixes: #11288
+
+    *Paul Nikitochkin*
+
 *   Remove deprecated nil-passing to the following `SchemaCache` methods:
     `primary_keys`, `tables`, `columns` and `columns_hash`.
 
diff --git a/activerecord/lib/active_record/associations/builder/belongs_to.rb b/activerecord/lib/active_record/associations/builder/belongs_to.rb
index d4e1a0dda1..81293e464d 100644
--- a/activerecord/lib/active_record/associations/builder/belongs_to.rb
+++ b/activerecord/lib/active_record/associations/builder/belongs_to.rb
@@ -92,7 +92,7 @@ module ActiveRecord::Associations::Builder
     end
 
     def self.touch_record(o, foreign_key, name, touch) # :nodoc:
-      old_foreign_id = o.attribute_was(foreign_key)
+      old_foreign_id = o.changed_attributes[foreign_key]
 
       if old_foreign_id
         klass      = o.association(name).klass
diff --git a/activerecord/test/cases/associations/belongs_to_associations_test.rb b/activerecord/test/cases/associations/belongs_to_associations_test.rb
index cc72ab7b2a..0267cdf6e0 100644
--- a/activerecord/test/cases/associations/belongs_to_associations_test.rb
+++ b/activerecord/test/cases/associations/belongs_to_associations_test.rb
@@ -1,4 +1,4 @@
-require "cases/helper"
+require 'cases/helper'
 require 'models/developer'
 require 'models/project'
 require 'models/company'
@@ -14,6 +14,8 @@ require 'models/sponsor'
 require 'models/member'
 require 'models/essay'
 require 'models/toy'
+require 'models/invoice'
+require 'models/line_item'
 
 class BelongsToAssociationsTest < ActiveRecord::TestCase
   fixtures :accounts, :companies, :developers, :projects, :topics,
@@ -324,6 +326,45 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_equal 1, Topic.find(topic.id)[:replies_count]
   end
 
+  def test_belongs_to_with_touch_option_on_touch
+    line_item = LineItem.create!
+    Invoice.create!(line_items: [line_item])
+
+    assert_queries(1) { line_item.touch }
+  end
+
+  def test_belongs_to_with_touch_option_on_touch_and_removed_parent
+    line_item = LineItem.create!
+    Invoice.create!(line_items: [line_item])
+
+    line_item.invoice = nil
+
+    assert_queries(2) { line_item.touch }
+  end
+
+  def test_belongs_to_with_touch_option_on_update
+    line_item = LineItem.create!
+    Invoice.create!(line_items: [line_item])
+
+    assert_queries(2) { line_item.update amount: 10 }
+  end
+
+  def test_belongs_to_with_touch_option_on_destroy
+    line_item = LineItem.create!
+    Invoice.create!(line_items: [line_item])
+
+    assert_queries(2) { line_item.destroy }
+  end
+
+  def test_belongs_to_with_touch_option_on_touch_and_reassigned_parent
+    line_item = LineItem.create!
+    Invoice.create!(line_items: [line_item])
+
+    line_item.invoice = Invoice.create!
+
+    assert_queries(3) { line_item.touch }
+  end
+
   def test_belongs_to_counter_after_update
     topic = Topic.create!(title: "37s")
     topic.replies.create!(title: "re: 37s", content: "rails")