Modified default_scope to merge with any pre-existing default_scope

and added AR::Base::clear_default_scope

- clear_default_scope provides users who rely on the old behaviour
  of each call to default_scope overwriting any previous default
  scopes an opportunity to maintain that behaviour.

[#4583 state:resolved]

Signed-off-by: José Valim <jose.valim@gmail.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 650a91b385..e7319ce8b9 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1190,7 +1190,11 @@ module ActiveRecord #:nodoc:
         #     default_scope order('last_name, first_name')
         #   end
         def default_scope(options = {})
-          self.default_scoping << construct_finder_arel(options)
+          self.default_scoping << construct_finder_arel(options, default_scoping.pop)
+        end
+
+        def clear_default_scope
+          self.default_scoping.clear
         end
 
         def scoped_methods #:nodoc: