Archives → Print Log was 404-storming the thumbnail endpoint on every
render: PrintLogEntry.thumbnail_path is copied by value from the archive
at write-time, but the FK on archive_id is ON DELETE SET NULL (#1378) so
log entries survive archive deletion to preserve stats history - and the
cached path keeps pointing at a file that was removed when the archive's
directory was deleted. Same shape for failed prints whose extractor never
wrote the thumbnail.
Two-part fix:
1. Route self-heals: get_print_log_thumbnail NULLs thumbnail_path on the
entry and commits before returning 404 when the file is missing on
disk. The frontend's <img> tag is gated on entry.thumbnail_path being
truthy, so the next fetch of the log list skips the request entirely.
2. Eager clear on archive delete: new _null_print_log_thumbnail_paths()
helper called from both soft_delete_archive and delete_archive before
the on-disk files are removed. Avoids the one-time storm for future
deletes; covers both the manual delete route and the auto-purge
sweeper at archive_purge.py.
Regression tests cover soft delete, hard delete via ArchiveService, and
the route's lazy-NULL for failed-print orphans where the file was never
written.
maziggy
cad63500a8