Fix offset with last.

Closes #7441

activerecord/CHANGELOG.md

@@ -1,3 +1,9 @@
+*   `Model.offset(4).last` now returns the 4th record from the end, not just last record.
+
+    Fixes #7441.
+
+    *kostya*
+
 *   `type_to_sql` returns a `String` for unmapped columns. This fixes an error
     when using unmapped array types in PG
 

activerecord/lib/active_record/relation/finder_methods.rb

@@ -384,7 +384,7 @@ module ActiveRecord
         @records.last
       else
         @last ||=
-          if offset_value || limit_value
+          if limit_value
             to_a.last
           else
             reverse_order.limit(1).to_a.first

activerecord/test/cases/finder_test.rb

@@ -720,6 +720,15 @@ class FinderTest < ActiveRecord::TestCase
     assert_raise(ArgumentError) { Topic.find_by_title_and_author_name("The First Topic") }
   end
 
+  def test_find_last_with_offset
+    devs = Developer.order('id').all
+
+    assert_equal devs[2], Developer.offset(2).first
+    assert_equal devs[-3], Developer.offset(2).last
+    assert_equal devs[-3], Developer.offset(2).last
+    assert_equal devs[-3], Developer.offset(2).order('id DESC').first
+  end
+
   def test_find_by_nil_attribute
     topic = Topic.find_by_last_read nil
     assert_not_nil topic