2 files changed, 16 insertions, 3 deletions
diff --git a/actionpack/lib/action_view/base.rb b/actionpack/lib/action_view/base.rb
index 23329d7f35..056dbc9529 100644
--- a/actionpack/lib/action_view/base.rb
+++ b/actionpack/lib/action_view/base.rb
@@ -141,6 +141,12 @@ module ActionView #:nodoc:
     cattr_accessor :streaming_completion_on_exception
     @@streaming_completion_on_exception = %("><script type="text/javascript">window.location = "/500.html"</script></html>)
 
+    # Specify whether rendering within namespaced controllers should prefix
+    # the partial paths for ActiveModel objects with the namespace.
+    # (e.g., an Admin::PostsController would render @post using /admin/posts/_post.erb)
+    cattr_accessor :prefix_partial_path_with_controller_namespace
+    @@prefix_partial_path_with_controller_namespace = true
+
     class_attribute :helpers
     class_attribute :_routes
     class_attribute :logger
diff --git a/actionpack/lib/action_view/renderer/partial_renderer.rb b/actionpack/lib/action_view/renderer/partial_renderer.rb
index d4c652c0d1..8b53867aea 100644
--- a/actionpack/lib/action_view/renderer/partial_renderer.rb
+++ b/actionpack/lib/action_view/renderer/partial_renderer.rb
@@ -245,12 +245,11 @@ module ActionView
   #     <%- end -%>
   #   <% end %>
   class PartialRenderer < AbstractRenderer
-    PARTIAL_NAMES = Hash.new { |h,k| h[k] = {} }
+    PREFIXED_PARTIAL_NAMES = Hash.new { |h,k| h[k] = {} }
 
     def initialize(*)
       super
       @context_prefix = @lookup_context.prefixes.first
-      @partial_names = PARTIAL_NAMES[@context_prefix]
     end
 
     def render(context, options, block)
@@ -423,7 +422,15 @@ module ActionView
         raise ArgumentError.new("'#{object.inspect}' is not an ActiveModel-compatible object. It must implement :to_partial_path.")
       end
 
-      @partial_names[path] ||= merge_prefix_into_object_path(@context_prefix, path.dup)
+      if @view.prefix_partial_path_with_controller_namespace
+        prefixed_partial_names[path] ||= merge_prefix_into_object_path(@context_prefix, path.dup)
+      else
+        path
+      end
+    end
+
+    def prefixed_partial_names
+      @prefixed_partial_names ||= PREFIXED_PARTIAL_NAMES[@context_prefix]
     end
 
     def merge_prefix_into_object_path(prefix, object_path)