Fix how routes inside namespaces are generated.

actionpack/lib/action_dispatch/routing/mapper.rb

@@ -726,7 +726,7 @@ module ActionDispatch
           path = options.delete(:path)
           action = args.first
 
-          if action && action.to_s =~ /^[A-Za-z_]\w*$/
+          if action.is_a?(Symbol) || (resource_method_scope? && action.to_s =~ /^[A-Za-z_]\w*$/)
             path = path_for_action(action, path)
             options[:action] ||= action
             options[:as] = name_for_action(action, options[:as])

actionpack/test/dispatch/routing_test.rb

@@ -660,7 +660,7 @@ class TestRoutingMapper < ActionDispatch::IntegrationTest
 
       get '/bookmark/remove'
       assert_equal 'bookmarks#destroy', @response.body
-      assert_equal '/bookmark/remove', remove_bookmark_path
+      assert_equal '/bookmark/remove', bookmark_remove_path
     end
   end
 
@@ -1195,7 +1195,7 @@ class TestRoutingMapper < ActionDispatch::IntegrationTest
 
   def test_match_shorthand_inside_namespace
     with_test_routes do
-      assert_equal '/account/shorthand', shorthand_account_path
+      assert_equal '/account/shorthand', account_shorthand_path
       get '/account/shorthand'
       assert_equal 'account#shorthand', @response.body
     end
@@ -1247,7 +1247,7 @@ class TestRoutingMapper < ActionDispatch::IntegrationTest
 
   def test_normalize_namespaced_matches
     with_test_routes do
-      assert_equal '/account/description', description_account_path
+      assert_equal '/account/description', account_description_path
 
       get '/account/description'
       assert_equal 'account#description', @response.body