Merge pull request #8053 from henrik/update_columns_with_primary_key

Unbreak update_column/update_columns for the primary key attribute.
Conflicts:
	activerecord/CHANGELOG.md
	activerecord/lib/active_record/persistence.rb
	activerecord/test/cases/persistence_test.rb

3 files changed, 17 insertions, 1 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 8c55c60769..aa68934099 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,5 +1,9 @@
 ## Rails 3.2.9 (unreleased)
 
+*   Fix bug where `update_columns` and `update_column` would not let you update the primary key column.
+
+    *Henrik Nyh*
+
 *   Decode URI encoded attributes on database connection URLs.
 
     *Shawn Veader*
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index 8a3c3fed7d..d492ac7f16 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -193,8 +193,12 @@ module ActiveRecord
       name = name.to_s
       raise ActiveRecordError, "#{name} is marked as readonly" if self.class.readonly_attributes.include?(name)
       raise ActiveRecordError, "can not update on a new record object" unless persisted?
+
+      updated_count = self.class.update_all({ name => value }, self.class.primary_key => id) == 1
+
       raw_write_attribute(name, value)
-      self.class.update_all({ name => value }, self.class.primary_key => id) == 1
+
+      updated_count == 1
     end
 
     # Updates the attributes of the model from the passed-in hash and saves the
diff --git a/activerecord/test/cases/persistence_test.rb b/activerecord/test/cases/persistence_test.rb
index e4b8caae52..66f884287d 100644
--- a/activerecord/test/cases/persistence_test.rb
+++ b/activerecord/test/cases/persistence_test.rb
@@ -505,6 +505,14 @@ class PersistencesTest < ActiveRecord::TestCase
     assert_equal 'super_title', t.title
   end
 
+  def test_update_column_changing_id
+    topic = Topic.find(1)
+    topic.update_column("id", 123)
+    assert_equal 123, topic.id
+    topic.reload
+    assert_equal 123, topic.id
+  end
+
   def test_update_attributes
     topic = Topic.find(1)
     assert !topic.approved?