wp-admin/includes/class-file-upload-upgrader.php:148Deletes the attachment/uploaded file.
bool public function cleanup() { if ( $this->id ) { wp_delete_attachment( $this->id ); } elseif ( file_exists( $this->package ) ) { return @unlink( $this->package ); } return true; }Introduced in 3.2.2. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/class-file-upload-upgrader.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.