Avoid leaking the first relation we call #first on

With the previous implementation, the block passed to
define_singleton_method, which will live forever as the method body,
captures the parameters (args and block) in its enclosure.

For the current_scope registry, that can include an AR::Relation.

1 files changed, 3 insertions, 3 deletions

diff --git a/activesupport/lib/active_support/per_thread_registry.rb b/activesupport/lib/active_support/per_thread_registry.rb
index ca2e4d5625..506dd950cb 100644
--- a/activesupport/lib/active_support/per_thread_registry.rb
+++ b/activesupport/lib/active_support/per_thread_registry.rb
@@ -43,9 +43,9 @@ module ActiveSupport
     protected
       def method_missing(name, *args, &block) # :nodoc:
         # Caches the method definition as a singleton method of the receiver.
-        define_singleton_method(name) do |*a, &b|
-          instance.public_send(name, *a, &b)
-        end
+        #
+        # By letting #delegate handle it, we avoid an enclosure that'll capture args.
+        singleton_class.delegate name, to: :instance
 
         send(name, *args, &block)
       end