Fix inspect with non-primary key id attribute

The `read_attribute` method always returns the primary key when asked to
read the `id` attribute, even if the primary key isn't named `id`, and
even if another attribute named `id` exists.

For the `inspect`, `attribute_for_inspect` and `pretty_print` methods,
this behaviour is undesirable, as they're used to examine the internal
state of the record. By using `_read_attribute` instead, we'll get the
real value of the `id` attribute.

1 files changed, 12 insertions, 0 deletions

diff --git a/activerecord/test/cases/core_test.rb b/activerecord/test/cases/core_test.rb
index f7fbf3ee8a..36e3d543cd 100644
--- a/activerecord/test/cases/core_test.rb
+++ b/activerecord/test/cases/core_test.rb
@@ -30,6 +30,11 @@ class CoreTest < ActiveRecord::TestCase
     assert_equal %(#<Topic id: 1, title: "The First Topic">), Topic.all.merge!(select: "id, title", where: "id = 1").first.inspect
   end
 
+  def test_inspect_instance_with_non_primary_key_id_attribute
+    topic = topics(:first).becomes(TitlePrimaryKeyTopic)
+    assert_match(/id: 1/, topic.inspect)
+  end
+
   def test_inspect_class_without_table
     assert_equal "NonExistentTable(Table doesn't exist)", NonExistentTable.inspect
   end
@@ -110,4 +115,11 @@ class CoreTest < ActiveRecord::TestCase
     PP.pp(subtopic.new, StringIO.new(actual))
     assert_equal "inspecting topic\n", actual
   end
+
+  def test_pretty_print_with_non_primary_key_id_attribute
+    topic = topics(:first).becomes(TitlePrimaryKeyTopic)
+    actual = +""
+    PP.pp(topic, StringIO.new(actual))
+    assert_match(/id: 1/, actual)
+  end
 end