make sure as is set before trying to build an #{as}_counter. [#2804 …

…state:resolved]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

actionpack/lib/action_view/partials.rb

@@ -218,7 +218,7 @@ def render_partial_collection(options = {}) #:nodoc:
             ActionController::RecordIdentifier.partial_path(object, controller.class.controller_path)
           template = _pick_partial_template(_partial_path)
           local_assigns[template.counter_name] = index
-          local_assigns["#{as.to_s}_counter".to_sym] = local_assigns[template.counter_name]
+          local_assigns["#{as.to_s}_counter".to_sym] = local_assigns[template.counter_name] if as
           result = template.render_partial(self, object, local_assigns.dup, as)
           index += 1
           result