Clear offset cache on CollectionProxy reset/reload

The `@offsets` cache is used by FinderMethods to cache records found by
find_nth. This cache is cleared in AR::Relation#reset, but not in
CollectionProxy#reset or CollectionProxy#reload.

Because of this, since #29098, calling #first/#find_nth/etc after
calling #reload or #reset on an association could return a stale record.
This is an issue both when the full association target is loaded and
when the item is loaded in #find_nth.

This commit solves the problem by clearing the `@offsets` cache in
CollectionProxy#reset and CollectionProxy#reload.

1 files changed, 2 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
index 8cdb508c43..88b05bbcfa 100644
--- a/activerecord/lib/active_record/associations/collection_proxy.rb
+++ b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -1088,6 +1088,7 @@ module ActiveRecord
       #   # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]
       def reload
         proxy_association.reload
+        @offsets = {}
         reset_scope
       end
 
@@ -1110,6 +1111,7 @@ module ActiveRecord
       def reset
         proxy_association.reset
         proxy_association.reset_scope
+        @offsets = {}
         reset_scope
       end