Allow a route to have :format => true

When format is true, it is mandatory (as opposed to :format => false).
This is currently not possible with resource routes, which automatically
make format optional by default.

actionpack/lib/action_dispatch/routing/mapper.rb

@@ -119,6 +119,8 @@ module ActionDispatch
               path
             elsif path.include?(":format") || path.end_with?('/')
               path
+            elsif @options[:format] == true
+              "#{path}.:format"
             else
               "#{path}(.:format)"
             end

actionpack/test/dispatch/mapper_test.rb

@@ -83,6 +83,13 @@ module ActionDispatch
         assert_equal '/*path', fakeset.conditions.first[:path_info]
         assert_nil fakeset.requirements.first[:path]
       end
+
+      def test_map_wildcard_with_format_true
+        fakeset = FakeSet.new
+        mapper = Mapper.new fakeset
+        mapper.match '/*path', :to => 'pages#show', :format => true
+        assert_equal '/*path.:format', fakeset.conditions.first[:path_info]
+      end
     end
   end
 end