delete_all raise an error if a limit is provided - fixes #4979

activerecord/lib/active_record/relation.rb

@@ -390,6 +390,8 @@ def destroy(id)
     # If you need to destroy dependent associations or call your <tt>before_*</tt> or
     # +after_destroy+ callbacks, use the +destroy_all+ method instead.
     def delete_all(conditions = nil)
+      raise ActiveRecordError.new("delete_all doesn't support limit scope") if self.limit_value
+
       if conditions
         where(conditions).delete_all
       else

activerecord/test/cases/relations_test.rb

@@ -688,6 +688,10 @@ def test_delete_all_loaded
     assert davids.loaded?
   end
 
+  def test_delete_all_limit_error
+    assert_raises(ActiveRecord::ActiveRecordError) { Author.limit(10).delete_all }
+  end
+
   def test_select_argument_error
     assert_raises(ArgumentError) { Developer.select }
   end