ActiveRecord: Fix eager loading so that giving a blank order clause generates valid SQL

2 files changed, 13 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index 283115a448..220ead4edb 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -243,7 +243,7 @@ module ActiveRecord
     end
 
     def construct_limited_ids_condition(relation)
-      orders = relation.order_values
+      orders = relation.order_values.map(&:presence).compact
       values = @klass.connection.distinct("#{@klass.connection.quote_table_name table_name}.#{primary_key}", orders)
 
       relation = relation.dup
diff --git a/activerecord/test/cases/associations/eager_test.rb b/activerecord/test/cases/associations/eager_test.rb
index f1d061133c..c6e451fc57 100644
--- a/activerecord/test/cases/associations/eager_test.rb
+++ b/activerecord/test/cases/associations/eager_test.rb
@@ -1048,4 +1048,16 @@ class EagerAssociationTest < ActiveRecord::TestCase
       assert_not_equal 0, post.comments.to_a.count
     end
   end
+
+  def test_join_eager_with_empty_order_should_generate_valid_sql
+    assert_nothing_raised(ActiveRecord::StatementInvalid) do
+      Post.includes(:comments).order("").where(:comments => {:body => "Thank you for the welcome"}).first
+    end
+  end
+
+  def test_join_eager_with_nil_order_should_generate_valid_sql
+    assert_nothing_raised(ActiveRecord::StatementInvalid) do
+      Post.includes(:comments).order(nil).where(:comments => {:body => "Thank you for the welcome"}).first
+    end
+  end
 end