clear cache on body close so that cache remains during rendering

fixes #13547

The body may use the local cache during rendering.  `call`ing the app
doesn't mean that rendering is finished, so we need to wait until
`close` is called on the body.

1 files changed, 8 insertions, 2 deletions

diff --git a/activesupport/lib/active_support/cache/strategy/local_cache.rb b/activesupport/lib/active_support/cache/strategy/local_cache.rb
index cea7eee924..4eaf57f385 100644
--- a/activesupport/lib/active_support/cache/strategy/local_cache.rb
+++ b/activesupport/lib/active_support/cache/strategy/local_cache.rb
@@ -1,5 +1,6 @@
 require 'active_support/core_ext/object/duplicable'
 require 'active_support/core_ext/string/inflections'
+require 'rack/body_proxy'
 
 module ActiveSupport
   module Cache
@@ -83,9 +84,14 @@ module ActiveSupport
 
           def call(env)
             LocalCacheRegistry.set_cache_for(local_cache_key, LocalStore.new)
-            @app.call(env)
-          ensure
+            response = @app.call(env)
+            response[2] = ::Rack::BodyProxy.new(response[2]) do
+              LocalCacheRegistry.set_cache_for(local_cache_key, nil)
+            end
+            response
+          rescue Exception
             LocalCacheRegistry.set_cache_for(local_cache_key, nil)
+            raise
           end
         end