Fix `last` with `offset` to behave consistently with loaded relation

Currently `last` with `offset` behaves incorrectly because `offset` can
not be reversed like `limit`. Therefore, `offset` should also be handled
like `limit`.

2 files changed, 5 insertions, 9 deletions

diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index b61e65cfb3..4bf346a512 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -148,7 +148,7 @@ module ActiveRecord
     #
     #   [#<Person id:4>, #<Person id:3>, #<Person id:2>]
     def last(limit = nil)
-      return find_last(limit) if loaded? || limit_value
+      return find_last(limit) if loaded? || has_limit_or_offset?
 
       result = ordered_relation.limit(limit)
       result = result.reverse_order!
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index 8369a10b5a..c0485a7be7 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -677,6 +677,10 @@ class FinderTest < ActiveRecord::TestCase
     assert_equal comments.limit(2).to_a.last(2), comments.limit(2).last(2)
     assert_equal comments.limit(2).to_a.last(3), comments.limit(2).last(3)
 
+    assert_equal comments.offset(2).to_a.last, comments.offset(2).last
+    assert_equal comments.offset(2).to_a.last(2), comments.offset(2).last(2)
+    assert_equal comments.offset(2).to_a.last(3), comments.offset(2).last(3)
+
     comments = comments.offset(1)
     assert_equal comments.limit(2).to_a.last, comments.limit(2).last
     assert_equal comments.limit(2).to_a.last(2), comments.limit(2).last(2)
@@ -1049,14 +1053,6 @@ 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")
-
-    assert_equal devs[2], Developer.offset(2).first
-    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