Fix double melody year in songinfo

private_includes/base/footer_with_songinfo.ily

@@ -143,7 +143,7 @@
             (translation (chain-assoc-get 'header:translation props #f))
             (pronunciation (chain-assoc-get 'header:pronunciation props #f))
             (year_text (if (string? (car poet-and-composers)) #f (chain-assoc-get 'header:year_text props #f)))
-            (year_melody (if (string? (car poet-and-composers)) #f (chain-assoc-get 'header:year_melody props #f))))
+            (year_melody (if (string? (cadr poet-and-composers)) #f (chain-assoc-get 'header:year_melody props #f))))
             (markup
               #:override (cons 'songinfo:poet-maybe-with-composer
                 (if (and poet-maybe-with-composer (not (and (string? poet-maybe-with-composer) (string-null? poet-maybe-with-composer)))) poet-maybe-with-composer #f))

private_includes/book/toc_include.ily

@@ -287,11 +287,8 @@ headerToTOC = #(define-music-function (parser location header label) (ly:book? s
             (compositionIds (find-author-ids-by 'composition authors))
             (adaptionIds (find-author-ids-by 'adaption authors))
             (bridgeIds (find-author-ids-by 'bridge authors))
-            (interludeIds (find-author-ids-by 'interlude authors))
-            (realAuthorIds (map car AUTHOR_DATA)))
-        (lset-intersection
-          equal?
-          realAuthorIds
+            (interludeIds (find-author-ids-by 'interlude authors)))
+        (delete-duplicates
           (append poetIds translatorIds (map car versePoetData) composerIds (map car verseComposerData) (map car voiceComposerData) compositionIds adaptionIds bridgeIds interludeIds))
     ))
     (let*