Improve heuristic for railties default name, otherwise railties may be named...

Improve heuristic for railties default name, otherwise railties may be named :railtie, :engine and so on.

railties/lib/rails/engine.rb

@@ -14,7 +14,7 @@ class << self
       alias :engine_names :railtie_names
 
       def inherited(base)
-        unless abstract_railtie?(base)
+        unless base.abstract_railtie?
           base.called_from = begin
             # Remove the line number from backtraces making sure we don't leave anything behind
             call_stack = caller.map { |p| p.split(':')[0..-2].join(':') }

railties/lib/rails/railtie.rb

@@ -9,7 +9,8 @@ class Railtie
 
     include Initializable
 
-    ABSTRACT_RAILTIES = %w(Rails::Plugin Rails::Engine Rails::Application)
+    ABSTRACT_RAILTIES = %w(Rails::Railtie Rails::Plugin Rails::Engine Rails::Application)
+    RAILTIES_TYPES    = ABSTRACT_RAILTIES.map { |r| r.split('::').last }
 
     class << self
       def subclasses
@@ -17,7 +18,7 @@ def subclasses
       end
 
       def inherited(base)
-        unless abstract_railtie?(base)
+        unless base.abstract_railtie?
           base.send(:include, self::Configurable)
           subclasses << base
         end
@@ -52,14 +53,16 @@ def generators(&blk)
         @generators
       end
 
-    protected
-
-      def abstract_railtie?(base)
-        ABSTRACT_RAILTIES.include?(base.name)
+      def abstract_railtie?
+        ABSTRACT_RAILTIES.include?(name)
       end
 
+    protected
+
       def default_name
-        ActiveSupport::Inflector.underscore(ActiveSupport::Inflector.demodulize(name))
+        namespaces = name.split("::")
+        namespaces.pop if RAILTIES_TYPES.include?(namespaces.last)
+        ActiveSupport::Inflector.underscore(namespaces.last).to_sym
       end
     end
 

railties/test/railties/railtie_test.rb

@@ -15,6 +15,14 @@ def app
       @app ||= Rails.application
     end
 
+    test "name can be retrieved from namespaced railties" do
+      module ActiveRailtie
+        class Railtie < Rails::Railtie; end
+      end
+
+      assert_equal :active_railtie, ActiveRailtie::Railtie.railtie_name
+    end
+
     test "can find railtie by name" do
       class TieA < Rails::Railtie; railtie_name :railtie_a; end
       class TieB < Rails::Railtie; railtie_name :railtie_b; end