From 37f3b4dc05288f94b73f44fc9fa0d0176d179a02 Mon Sep 17 00:00:00 2001
From: Peter Fry <peter.fry@mac.com>
Date: Wed, 3 Jun 2020 11:21:12 -0400
Subject: [PATCH] Do not mark Postgresql MAC address and UUID attributes as
 changed when the assigned value only varies by case.

Fix Rubocop warnings.

Fix merge conflict error.

Fix merge conflict error.
---
 activerecord/CHANGELOG.md                     |  4 ++++
 .../connection_adapters/postgresql/oid.rb     |  1 +
 .../postgresql/oid/macaddr.rb                 | 20 +++++++++++++++++++
 .../postgresql/oid/uuid.rb                    |  2 +-
 .../connection_adapters/postgresql_adapter.rb |  2 +-
 .../cases/adapters/postgresql/network_test.rb |  6 ++++++
 .../cases/adapters/postgresql/uuid_test.rb    |  6 ++++++
 7 files changed, 39 insertions(+), 2 deletions(-)
 create mode 100644 activerecord/lib/active_record/connection_adapters/postgresql/oid/macaddr.rb

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index ebb358e5c8..35b7995339 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Do not mark Postgresql MAC address and UUID attributes as changed when the assigned value only varies by case.
+
+    *Peter Fry*
+
 *   Resolve issue with insert_all unique_by option when used with expression index.
 
     When the `:unique_by` option of `ActiveRecord::Persistence.insert_all` and
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
index 247a25054e..b70a88539d 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
@@ -12,6 +12,7 @@ require "active_record/connection_adapters/postgresql/oid/enum"
 require "active_record/connection_adapters/postgresql/oid/hstore"
 require "active_record/connection_adapters/postgresql/oid/inet"
 require "active_record/connection_adapters/postgresql/oid/jsonb"
+require "active_record/connection_adapters/postgresql/oid/macaddr"
 require "active_record/connection_adapters/postgresql/oid/money"
 require "active_record/connection_adapters/postgresql/oid/oid"
 require "active_record/connection_adapters/postgresql/oid/point"
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/macaddr.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/macaddr.rb
new file mode 100644
index 0000000000..d0380ea750
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/macaddr.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Macaddr < Type::String # :nodoc:
+          def type
+            :macaddr
+          end
+
+          private
+            def cast_value(value)
+              value.to_s.downcase
+            end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb
index 74a28eef58..4548d75e7e 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb
@@ -15,7 +15,7 @@ module ActiveRecord
 
           private
             def cast_value(value)
-              casted = value.to_s
+              casted = value.to_s.downcase
               casted if casted.match?(ACCEPTABLE_UUID)
             end
         end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index e6d59cb92c..fc5191fae8 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -535,7 +535,7 @@ module ActiveRecord
           m.register_type "uuid", OID::Uuid.new
           m.register_type "xml", OID::Xml.new
           m.register_type "tsvector", OID::SpecializedString.new(:tsvector)
-          m.register_type "macaddr", OID::SpecializedString.new(:macaddr)
+          m.register_type "macaddr", OID::Macaddr.new
           m.register_type "citext", OID::SpecializedString.new(:citext)
           m.register_type "ltree", OID::SpecializedString.new(:ltree)
           m.register_type "line", OID::SpecializedString.new(:line)
diff --git a/activerecord/test/cases/adapters/postgresql/network_test.rb b/activerecord/test/cases/adapters/postgresql/network_test.rb
index 736570451b..8b62a52796 100644
--- a/activerecord/test/cases/adapters/postgresql/network_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/network_test.rb
@@ -93,4 +93,10 @@ class PostgresqlNetworkTest < ActiveRecord::PostgreSQLTestCase
     assert_match %r{t\.cidr\s+"cidr_address",\s+default: "192\.168\.1\.0/24"}, output
     assert_match %r{t\.macaddr\s+"mac_address",\s+default: "ff:ff:ff:ff:ff:ff"}, output
   end
+
+  def test_mac_address_change_case_does_not_mark_dirty
+    model = PostgresqlNetworkAddress.create(mac_address: "Ab:Cd:Ef:01:02:03")
+    model.mac_address = model.mac_address.swapcase
+    assert_not_predicate model, :changed?
+  end
 end
diff --git a/activerecord/test/cases/adapters/postgresql/uuid_test.rb b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
index a1c985fc71..f4b85b2c8f 100644
--- a/activerecord/test/cases/adapters/postgresql/uuid_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
@@ -120,6 +120,12 @@ class PostgresqlUUIDTest < ActiveRecord::PostgreSQLTestCase
     assert_empty UUIDType.where(guid: "foobar")
   end
 
+  def test_uuid_change_case_does_not_mark_dirty
+    model = UUIDType.create!(guid: "abcd-0123-4567-89ef-dead-beef-0101-1010")
+    model.guid = model.guid.swapcase
+    assert_not_predicate model, :changed?
+  end
+
   class DuckUUID
     def initialize(uuid)
       @uuid = uuid