Add #concat to Rails::Application::Path

railties/lib/rails/configuration.rb

@@ -76,7 +76,7 @@ module Rails
       @paths.config.locales      = "config/locales"
       @paths.config.environments = "config/environments"
 
-      builtin_directories.each { |dir| @paths.app.controllers << dir }
+      @paths.app.controllers.concat builtin_directories
 
       @paths.app.load_path!
       @paths.app.metals.load_path!

railties/lib/rails/paths.rb

@@ -80,6 +80,10 @@ module Rails
         @paths.unshift path
       end
 
+      def concat(paths)
+        @paths.concat paths
+      end
+
       def load_once!
         @load_once = true
         @root.load_once.push *self.paths

railties/test/paths_test.rb

@@ -52,6 +52,12 @@ class PathsTest < ActiveSupport::TestCase
     assert_equal ["/app", "/app2"], @root.app.to_a
   end
 
+  test "adding multiple physical paths using concat" do
+    @root.app = "/app"
+    @root.app.concat ["/app2", "/app3"]
+    assert_equal ["/app", "/app2", "/app3"], @root.app.to_a
+  end
+
   test "adding multiple physical paths using #unshift" do
     @root.app = "/app"
     @root.app.unshift "/app2"
@@ -62,6 +68,7 @@ class PathsTest < ActiveSupport::TestCase
     assert_raise(RuntimeError) { Rails::Application::Root.new(["/fiz", "/biz"]) }
     assert_raise(NoMethodError) { @root.push "/biz"    }
     assert_raise(NoMethodError) { @root.unshift "/biz" }
+    assert_raise(NoMethodError) { @root.concat ["/biz"]}
     assert_raise(NoMethodError) { @root << "/biz"      }
   end