Add partial iteration variable to template keys

When rendering heterogeneous collection using `render @collection` or
`render partial: @collection`, the expected `<partial_name>_iteration`
variable is missing due to `find_template` not having the name of the
iteration variable included in its cache keys.

1 files changed, 9 insertions, 0 deletions

diff --git a/actionview/test/template/render_test.rb b/actionview/test/template/render_test.rb
index d189b2aa87..7f76916b72 100644
--- a/actionview/test/template/render_test.rb
+++ b/actionview/test/template/render_test.rb
@@ -301,6 +301,15 @@ module RenderTestCases
       @view.render(partial: "test/local_inspector", collection: [ Customer.new("mary") ])
   end
 
+  def test_render_partial_collection_with_different_partials_still_provides_partial_iteration
+    a = {}
+    b = {}
+    def a.to_partial_path; "test/partial_iteration_1"; end
+    def b.to_partial_path; "test/partial_iteration_2"; end
+
+    assert_equal "local-variable\nlocal-variable", @controller_view.render([a, b])
+  end
+
   def test_render_partial_with_empty_collection_should_return_nil
     assert_nil @view.render(partial: "test/customer", collection: [])
   end