Implement limit & offset for ourselves

We know the query will return exactly one row for each entry in the
`ids` array, so we can do all the limit/offset calculations on that
array, in advance.

I also split our new ordered-ids behaviour out of the existing
`find_some` method: especially with this change, the conditionals were
overwhelming the actual logic.

1 files changed, 2 insertions, 2 deletions

diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index 47059fe9e4..3c3f3284ac 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -109,7 +109,7 @@ class FinderTest < ActiveRecord::TestCase
     assert_equal 'The Fifth Topic of the day',  records[2].title
   end
 
-  def test_find_with_ids_and_offset # failing with offset
+  def test_find_with_ids_and_offset
     records = Topic.offset(2).find([3,2,5,1,4])
     assert_equal 3, records.size
     assert_equal 'The Fifth Topic of the day',  records[0].title
@@ -261,7 +261,7 @@ class FinderTest < ActiveRecord::TestCase
     assert_equal topics(:second).title, Topic.find([2]).first.title
   end
 
-  def test_find_by_ids_with_limit_and_offset # failing with offset
+  def test_find_by_ids_with_limit_and_offset
     assert_equal 2, Entrant.limit(2).find([1,3,2]).size
     entrants = Entrant.limit(3).offset(2).find([1,3,2])
     assert_equal 1, entrants.size