ActiveRecord::Base.joins should allow single nil argument [#6181 state:resolved]

activerecord/lib/active_record/relation/query_methods.rb

@@ -63,7 +63,7 @@ def order(*args)
     end
 
     def joins(*args)
-      return self if args.blank?
+      return self if args.compact.blank?
 
       relation = clone
 

activerecord/test/cases/relations_test.rb

@@ -184,6 +184,10 @@ def test_select_with_block
     assert_equal [2, 4, 6, 8, 10], even_ids.sort
   end
 
+  def test_joins_with_nil_argument
+    assert_nothing_raised { DependentFirm.joins(nil).first }
+  end
+
   def test_finding_with_hash_conditions_on_joined_table
     firms = DependentFirm.joins(:account).where({:name => 'RailsCore', :accounts => { :credit_limit => 55..60 }}).to_a
     assert_equal 1, firms.size