Unscope update_column(s) query to ignore default scope

When applying default_scope to a class with a where clause, using
update_column(s) could generate a query that would not properly update
the record due to the where clause from the default_scope being applied
to the update query.

    class User < ActiveRecord::Base
      default_scope where(active: true)
    end

    user = User.first
    user.active = false
    user.save!

    user.update_column(:active, true) # => false

In this situation we want to skip the default_scope clause and just
update the record based on the primary key. With this change:

    user.update_column(:active, true) # => true

Fixes #8436.

activerecord/CHANGELOG.md

@@ -1,5 +1,31 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Unscope `update_column(s)` query to ignore default scope.
+
+    When applying `default_scope` to a class with a where clause, using
+    `update_column(s)` could generate a query that would not properly update
+    the record due to the where clause from the `default_scope` being applied
+    to the update query.
+
+        class User < ActiveRecord::Base
+          default_scope where(active: true)
+        end
+
+        user = User.first
+        user.active = false
+        user.save!
+
+        user.update_column(:active, true) # => false
+
+    In this situation we want to skip the default_scope clause and just
+    update the record based on the primary key. With this change:
+
+        user.update_column(:active, true) # => true
+
+    Fixes #8436.
+
+    *Carlos Antonio da Silva*
+
 *   SQLite adapter no longer corrupts binary data if the data contains `%00`.
 
     *Chris Feist*

activerecord/lib/active_record/persistence.rb

@@ -259,7 +259,7 @@ module ActiveRecord
         verify_readonly_attribute(key.to_s)
       end
 
-      updated_count = self.class.where(self.class.primary_key => id).update_all(attributes)
+      updated_count = self.class.unscoped.where(self.class.primary_key => id).update_all(attributes)
 
       attributes.each do |k, v|
         raw_write_attribute(k, v)

activerecord/test/cases/persistence_test.rb

@@ -512,6 +512,14 @@ class PersistencesTest < ActiveRecord::TestCase
     assert_equal 'super_title', t.title
   end
 
+  def test_update_column_with_default_scope
+    developer = DeveloperCalledDavid.first
+    developer.name = 'John'
+    developer.save!
+
+    assert developer.update_column(:name, 'Will'), 'did not update record due to default scope'
+  end
+
   def test_update_columns
     topic = Topic.find(1)
     topic.update_columns({ "approved" => true, title: "Sebastian Topic" })
@@ -616,6 +624,14 @@ class PersistencesTest < ActiveRecord::TestCase
     assert_equal true, topic.update_columns(title: "New title")
   end
 
+  def test_update_columns_with_default_scope
+    developer = DeveloperCalledDavid.first
+    developer.name = 'John'
+    developer.save!
+
+    assert developer.update_columns(name: 'Will'), 'did not update record due to default scope'
+  end
+
   def test_update_attributes
     topic = Topic.find(1)
     assert !topic.approved?