TOC: offset for page numbers if first page is not page 1

orchestrallily.ily

@@ -824,7 +824,10 @@ removecuefilter = #(define-music-function (parser location music) (ly:music?)
 
 
 #(define (oly:create-toc-file layout pages)
-  (let* ((label-table (ly:output-def-lookup layout 'label-page-table)))
+  (let* ((label-table (ly:output-def-lookup layout 'label-page-table))
+	 ;; The page numbers are pages counts in the pdf file, not visible page number!
+	 ;; So we have to offset them if the first page is not page #1
+	 (first-page-offset (1- (ly:output-def-lookup layout 'first-page-number))))
     (if (not (null? label-table))
       (let* ((format-line (lambda (toc-item)
              (let* ((label (car toc-item))
@@ -832,7 +835,7 @@ removecuefilter = #(define-music-function (parser location music) (ly:music?)
                     (label-page (and (list? label-table)
                                      (assoc label label-table)))
                     (page (and label-page (cdr label-page))))
-               (format #f "~a, section, 1, {~a}, ~a" page text label))))
+               (format #f "~a, section, 1, {~a}, ~a" (- page first-page-offset) text label))))
              (formatted-toc-items (map format-line (toc-items)))
              (whole-string (string-join formatted-toc-items ",\n"))
              (output-name (ly:parser-output-name parser))