3 files changed, 24 insertions, 0 deletions
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index 991145bed4..d6c48b99f3 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -1571,4 +1571,22 @@ class BasicsTest < ActiveRecord::TestCase
 
     assert_not topic.id_changed?
   end
+
+  test "ignored columns are not present in columns_hash" do
+    cache_columns = Developer.connection.schema_cache.columns_hash(Developer.table_name)
+    assert_includes cache_columns.keys, 'first_name'
+    refute_includes Developer.columns_hash.keys, 'first_name'
+  end
+
+  test "ignored columns have no attirbute methods" do
+    refute Developer.new.respond_to?(:first_name)
+    refute Developer.new.respond_to?(:first_name=)
+    refute Developer.new.respond_to?(:first_name?)
+  end
+
+  test "ignored columns don't prevent explicit declaration of attribute methods" do
+    assert Developer.new.respond_to?(:last_name)
+    assert Developer.new.respond_to?(:last_name=)
+    assert Developer.new.respond_to?(:last_name?)
+  end
 end
diff --git a/activerecord/test/models/developer.rb b/activerecord/test/models/developer.rb
index 8ac7a9df6a..7565e8f967 100644
--- a/activerecord/test/models/developer.rb
+++ b/activerecord/test/models/developer.rb
@@ -7,6 +7,8 @@ module DeveloperProjectsAssociationExtension2
 end
 
 class Developer < ActiveRecord::Base
+  self.ignored_columns = %w(first_name last_name)
+
   has_and_belongs_to_many :projects do
     def find_most_recent
       order("id DESC").first
@@ -61,6 +63,9 @@ class Developer < ActiveRecord::Base
     developer.audit_logs.build :message => "Computer created"
   end
 
+  attr_accessor :last_name
+  define_attribute_method 'last_name'
+
   def log=(message)
     audit_logs.build :message => message
   end
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 4c6d1ef3ce..4b7272f10a 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -250,6 +250,7 @@ ActiveRecord::Schema.define do
 
   create_table :developers, force: true do |t|
     t.string   :name
+    t.string   :first_name
     t.integer  :salary, default: 70000
     if subsecond_precision_supported?
       t.datetime :created_at, precision: 6