1 files changed, 4 insertions, 4 deletions
diff --git a/actionpack/lib/action_dispatch/routing/inspector.rb b/actionpack/lib/action_dispatch/routing/inspector.rb
index 120bc54333..71a0c5e826 100644
--- a/actionpack/lib/action_dispatch/routing/inspector.rb
+++ b/actionpack/lib/action_dispatch/routing/inspector.rb
@@ -69,7 +69,7 @@ module ActionDispatch
       end
 
       def internal?
-        controller.to_s =~ %r{\Arails/(info|welcome)} || path =~ %r{\A#{Rails.application.config.assets.prefix}}
+        controller.to_s =~ %r{\Arails/(info|mailers|welcome)} || path =~ %r{\A#{Rails.application.config.assets.prefix}\z}
       end
 
       def engine?
@@ -194,9 +194,9 @@ module ActionDispatch
         end
 
         def widths(routes)
-          [routes.map { |r| r[:name].length }.max,
-           routes.map { |r| r[:verb].length }.max,
-           routes.map { |r| r[:path].length }.max]
+          [routes.map { |r| r[:name].length }.max || 0,
+           routes.map { |r| r[:verb].length }.max || 0,
+           routes.map { |r| r[:path].length }.max || 0]
         end
     end