;; skip booktitles.
(if (and
- (not
- (ly:get-option 'preview-include-book-title))
- (< 1 (length systems))
- (paper-system-title? (list-ref systems 0))
- (paper-system-title? (list-ref systems 1)))
+ (not (ly:get-option 'preview-include-book-title))
+ (pair? systems)
+ (ly:paper-system-property (car systems) 'is-book-title #f))
+
(set! systems (cdr systems)))
(for-each