1 files changed, 2 insertions, 3 deletions
diff --git a/actionpack/lib/action_dispatch/routing/deprecated_mapper.rb b/actionpack/lib/action_dispatch/routing/deprecated_mapper.rb
index 0564ba9797..8ce6b2f6d5 100644
--- a/actionpack/lib/action_dispatch/routing/deprecated_mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/deprecated_mapper.rb
@@ -113,8 +113,7 @@ module ActionDispatch
           end
         end
 
-        possible_names = Routing.possible_controllers.collect { |n| Regexp.escape(n) }
-        requirements[:controller] ||= Regexp.union(*possible_names)
+        requirements[:controller] ||= @set.controller_constraints
 
         if defaults[:controller]
           defaults[:action] ||= 'index'
@@ -176,7 +175,7 @@ module ActionDispatch
               optional = false
             elsif segment =~ /^:(\w+)$/
               if defaults.has_key?($1.to_sym)
-                defaults.delete($1.to_sym)
+                defaults.delete($1.to_sym) if defaults[$1.to_sym].nil?
               else
                 optional = false
               end