Cached collections only work if there is one template

Cached collections only work if there is one template.  If there are
more than one templates, the caching mechanism doesn't have a key.

1 files changed, 11 insertions, 3 deletions

diff --git a/actionview/lib/action_view/renderer/partial_renderer.rb b/actionview/lib/action_view/renderer/partial_renderer.rb
index 801916954f..75bca3d0c4 100644
--- a/actionview/lib/action_view/renderer/partial_renderer.rb
+++ b/actionview/lib/action_view/renderer/partial_renderer.rb
@@ -308,6 +308,9 @@ module ActionView
         template = find_partial(@path, @template_keys)
         @variable ||= template.variable
       else
+        if options[:cached]
+          raise NotImplementedError, "render caching requires a template. Please specify a partial when rendering"
+        end
         template = nil
       end
 
@@ -337,9 +340,14 @@ module ActionView
             spacer = find_template(@options[:spacer_template], @locals.keys).render(view, @locals)
           end
 
-          cache_collection_render(payload, view, template) do
-            template ? collection_with_template(view, template) : collection_without_template(view)
-          end.join(spacer).html_safe
+          collection_body = if template
+            cache_collection_render(payload, view, template) do
+              collection_with_template(view, template)
+            end
+          else
+            collection_without_template(view)
+          end
+          collection_body.join(spacer).html_safe
         end
       end