Merge pull request #14993 from jonatack/patch-7

Follow-up to #14990 [ci skip]

activerecord/lib/active_record/associations/has_many_through_association.rb

@@ -12,10 +12,11 @@ def initialize(owner, reflection)
         @through_association = nil
       end
 
-      # Returns the size of the collection by executing a SELECT COUNT(*) query if the collection hasn't been
-      # loaded and calling collection.size if it has. If it's more likely than not that the collection does
-      # have a size larger than zero, and you need to fetch that collection afterwards, it'll take one fewer
-      # SELECT query if you use #length.
+      # Returns the size of the collection by executing a SELECT COUNT(*) query
+      # if the collection hasn't been loaded, and by calling collection.size if
+      # it has. If the collection will likely have a size greater than zero,
+      # and if fetching the collection will be needed afterwards, one less
+      # SELECT query will be generated by using #length instead.
       def size
         if has_cached_counter?
           owner.read_attribute cached_counter_attribute_name(reflection)
@@ -72,13 +73,11 @@ def through_association
           @through_association ||= owner.association(through_reflection.name)
         end
 
-        # We temporarily cache through record that has been built, because if we build a
-        # through record in build_record and then subsequently call insert_record, then we
-        # want to use the exact same object.
+        # The through record (built with build_record) is temporarily cached
+        # so that it may be reused if insert_record is subsequently called.
         #
-        # However, after insert_record has been called, we clear the cache entry because
-        # we want it to be possible to have multiple instances of the same record in an
-        # association
+        # However, after insert_record has been called, the cache is cleared in
+        # order to allow multiple instances of the same record in an association.
         def build_through_record(record)
           @through_records[record.object_id] ||= begin
             ensure_mutable