BUG #18342: pg_rewind copy all files found in pg_wal source directory

The following bug has been logged on the website:

Bug reference: 18342
Logged by: Marc Rechté
Email address: mrechte@gmail.com
PostgreSQL version: 16.1
Operating system: RHEL 9
Description:

Hello
We noticed that pg_rewind retrieves all files from pg_wal source database
directory.
This is usually not a problem, except if one has created a FILLER file in
order to take action in case the WAL file system becomes full.
pg_rewind should only retrieve WAL files from that directory.