1 files changed, 17 insertions, 11 deletions
diff --git a/actionpack/lib/action_controller/routing/generation/polymorphic_routes.rb b/actionpack/lib/action_controller/routing/generation/polymorphic_routes.rb
index 159d869a54..2adf3575a7 100644
--- a/actionpack/lib/action_controller/routing/generation/polymorphic_routes.rb
+++ b/actionpack/lib/action_controller/routing/generation/polymorphic_routes.rb
@@ -50,6 +50,7 @@ module ActionController
     #   polymorphic_url([blog, post]) # => "http://example.com/blogs/1/posts/1"
     #   polymorphic_url([:admin, blog, post]) # => "http://example.com/admin/blogs/1/posts/1"
     #   polymorphic_url([user, :blog, post]) # => "http://example.com/users/1/blog/posts/1"
+    #   polymorphic_url(Comment) # => "http://example.com/comments"
     #
     # ==== Options
     #
@@ -70,6 +71,9 @@ module ActionController
     #   record = Comment.new
     #   polymorphic_url(record)  # same as comments_url()
     #
+    #   # the class of a record will also map to the collection
+    #   polymorphic_url(Comment) # same as comments_url()
+    #
     def polymorphic_url(record_or_hash_or_array, options = {})
       if record_or_hash_or_array.kind_of?(Array)
         record_or_hash_or_array = record_or_hash_or_array.compact
@@ -86,17 +90,19 @@ module ActionController
         else        [ record_or_hash_or_array ]
       end
 
-      inflection =
-        case
-        when options[:action].to_s == "new"
-          args.pop
-          :singular
-        when record.respond_to?(:new_record?) && record.new_record?
-          args.pop
-          :plural
-        else
-          :singular
-        end
+      inflection = if options[:action].to_s == "new"
+        args.pop
+        :singular
+      elsif (record.respond_to?(:new_record?) && record.new_record?) ||
+            (record.respond_to?(:destroyed?) && record.destroyed?)
+        args.pop
+        :plural
+      elsif record.is_a?(Class)
+        args.pop
+        :plural
+      else
+        :singular
+      end
 
       args.delete_if {|arg| arg.is_a?(Symbol) || arg.is_a?(String)}