Make sure a namespaced <%= render form %> still renders the _form partial [#4784 state:resolved]

Signed-off-by: José Valim <jose.valim@gmail.com>

3 files changed, 13 insertions, 1 deletions

diff --git a/actionpack/lib/action_view/render/partials.rb b/actionpack/lib/action_view/render/partials.rb
index 85f67d4f14..fd896c263d 100644
--- a/actionpack/lib/action_view/render/partials.rb
+++ b/actionpack/lib/action_view/render/partials.rb
@@ -316,7 +316,7 @@ module ActionView
 
           object.class.model_name.partial_path.dup.tap do |partial|
             path = @view.controller_path
-            partial.insert(0, "#{File.dirname(path)}/") if path.include?(?/)
+            partial.insert(0, "#{File.dirname(path)}/") if partial.include?(?/) && path.include?(?/)
           end
         end
       end
diff --git a/actionpack/test/controller/render_test.rb b/actionpack/test/controller/render_test.rb
index e3ed097c67..a57a12f271 100644
--- a/actionpack/test/controller/render_test.rb
+++ b/actionpack/test/controller/render_test.rb
@@ -7,6 +7,10 @@ module Fun
     # :ported:
     def hello_world
     end
+    
+    def nested_partial_with_form_builder
+      render :partial => ActionView::Helpers::FormBuilder.new(:post, nil, view_context, {}, Proc.new {})
+    end
   end
 end
 
@@ -1230,6 +1234,13 @@ class RenderTest < ActionController::TestCase
     assert_match(/<label/, @response.body)
     assert_template('test/_labelling_form')
   end
+  
+  def test_nested_partial_with_form_builder
+    @controller = Fun::GamesController.new
+    get :nested_partial_with_form_builder
+    assert_match(/<label/, @response.body)
+    assert_template('fun/games/_form')
+  end
 
   def test_partial_collection
     get :partial_collection
diff --git a/actionpack/test/fixtures/fun/games/_form.erb b/actionpack/test/fixtures/fun/games/_form.erb
new file mode 100644
index 0000000000..01107f1cb2
--- /dev/null
+++ b/actionpack/test/fixtures/fun/games/_form.erb
@@ -0,0 +1 @@
+<%= form.label :title %>