From 3a48b83e5eec62a5d2bfab1a118c24b45345388c Mon Sep 17 00:00:00 2001
From: Andrew White <andyw@pixeltrix.co.uk>
Date: Sun, 5 Jan 2014 19:58:04 +0000
Subject: [PATCH] Allow an absolute controller path inside a module scope

Fixes #12777
---
 actionpack/CHANGELOG.md                          |  4 ++++
 actionpack/lib/action_dispatch/routing/mapper.rb |  8 ++++++--
 actionpack/test/dispatch/routing_test.rb         | 12 ++++++++++++
 guides/source/routing.md                         |  2 ++
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index bf608e162b..944bf18113 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Allow an absolute controller path inside a module scope
+
+    Fixes #12777
+
 *   Unique the segment keys array for non-optimized url helpers
 
     In Rails 3.2 you only needed pass an argument for dynamic segment once so
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index 4bf2dc6e23..18f37dc732 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -218,8 +218,12 @@ def default_controller_and_action
               controller ||= default_controller
               action     ||= default_action
 
-              unless controller.is_a?(Regexp)
-                controller = [@scope[:module], controller].compact.join("/").presence
+              if @scope[:module] && !controller.is_a?(Regexp)
+                if controller =~ %r{\A/}
+                  controller = controller[1..-1]
+                else
+                  controller = [@scope[:module], controller].compact.join("/").presence
+                end
               end
 
               if controller.is_a?(String) && controller =~ %r{\A/}
diff --git a/actionpack/test/dispatch/routing_test.rb b/actionpack/test/dispatch/routing_test.rb
index 840c157642..5a532dc38f 100644
--- a/actionpack/test/dispatch/routing_test.rb
+++ b/actionpack/test/dispatch/routing_test.rb
@@ -2882,6 +2882,18 @@ def test_multiple_positional_args_with_the_same_name
     assert_equal '/downloads/1/1.tar', download_path('1', '1')
   end
 
+  def test_absolute_controller_namespace
+    draw do
+      namespace :foo do
+        get '/', to: '/bar#index', as: 'root'
+      end
+    end
+
+    get '/foo'
+    assert_equal 'bar#index', @response.body
+    assert_equal '/foo', foo_root_path
+  end
+
 private
 
   def draw(&block)
diff --git a/guides/source/routing.md b/guides/source/routing.md
index 3375293b5a..70d4722068 100644
--- a/guides/source/routing.md
+++ b/guides/source/routing.md
@@ -239,6 +239,8 @@ In each of these cases, the named routes remain the same as if you did not use `
 | PATCH/PUT | /admin/posts/:id      | posts#update      | post_path(:id)      |
 | DELETE    | /admin/posts/:id      | posts#destroy     | post_path(:id)      |
 
+TIP: _If you need to use a different controller namespace inside a `namespace` block you can specify an absolute controller path, e.g: `get '/foo' => '/foo#index'`._
+
 ### Nested Resources
 
 It's common to have resources that are logically children of other resources. For example, suppose your application includes these models:
-- 
GitLab