From 5b2517c7f542a333fdfbfe9e0f15d2ac8fc4d8d1 Mon Sep 17 00:00:00 2001
From: Thomas Morley <thomasmorley65@gmail.com>
Date: Mon, 25 Jan 2016 00:53:34 +0100
Subject: [PATCH 1/1] make select-head-glyph and note-head::calc-glyph-name
 more robust

Issue 4753

In case style is not a symbol.
---
 scm/output-lib.scm | 102 ++++++++++++++++++++++++---------------------
 1 file changed, 55 insertions(+), 47 deletions(-)

diff --git a/scm/output-lib.scm b/scm/output-lib.scm
index dcec6ae939..733531c3c7 100644
--- a/scm/output-lib.scm
+++ b/scm/output-lib.scm
@@ -395,56 +395,64 @@
 (define-public (select-head-glyph style log)
   "Select a note head glyph string based on note head style @var{style}
 and duration-log @var{log}."
-  (case style
-    ;; "default" style is directly handled in note-head.cc as a
-    ;; special case (HW says, mainly for performance reasons).
-    ;; Therefore, style "default" does not appear in this case
-    ;; statement.  -- jr
-    ((xcircle) "2xcircle")
-    ((harmonic) "0harmonic")
-    ((harmonic-black) "2harmonic")
-    ((harmonic-mixed) (if (<= log 1) "0harmonic"
-                          "2harmonic"))
-    ((baroque)
-     ;; Oops, I actually would not call this "baroque", but, for
-     ;; backwards compatibility to 1.4, this is supposed to take
-     ;; brevis, longa and maxima from the neo-mensural font and all
-     ;; other note heads from the default font.  -- jr
-     (if (< log 0)
-         (string-append (number->string log) "neomensural")
-         (number->string log)))
-    ((altdefault)
-     ;; Like default, but brevis is drawn with double vertical lines
-     (if (= log -1)
-         (string-append (number->string log) "double")
-         (number->string log)))
-    ((mensural)
-     (string-append (number->string log) (symbol->string style)))
-    ((petrucci)
-     (if (< log 0)
-         (string-append (number->string log) "mensural")
-         (string-append (number->string log) (symbol->string style))))
-    ((blackpetrucci)
-     (if (< log 0)
-         (string-append (number->string log) "blackmensural")
-         (string-append (number->string log) (symbol->string style))))
-    ((semipetrucci)
-     (if (< log 0)
-         (string-append (number->string log) "semimensural")
-         (string-append (number->string log) "petrucci")))
-    ((neomensural)
-     (string-append (number->string log) (symbol->string style)))
-    ((kievan)
-     (string-append (number->string log) "kievan"))
-    (else
-     (if (string-match "vaticana*|hufnagel*|medicaea*" (symbol->string style))
-         (symbol->string style)
-         (string-append (number->string (max 0 log))
-                        (symbol->string style))))))
+  (if (symbol? style)
+      (case style
+        ;; "default" style is directly handled in note-head.cc as a
+        ;; special case (HW says, mainly for performance reasons).
+        ;; Therefore, style "default" does not appear in this case
+        ;; statement.  -- jr
+        ;; Though we not to care if style is '(), see below.  -- harm
+        ((xcircle) "2xcircle")
+        ((harmonic) "0harmonic")
+        ((harmonic-black) "2harmonic")
+        ((harmonic-mixed) (if (<= log 1) "0harmonic"
+                              "2harmonic"))
+        ((baroque)
+         ;; Oops, I actually would not call this "baroque", but, for
+         ;; backwards compatibility to 1.4, this is supposed to take
+         ;; brevis, longa and maxima from the neo-mensural font and all
+         ;; other note heads from the default font.  -- jr
+         (if (< log 0)
+             (string-append (number->string log) "neomensural")
+             (number->string log)))
+        ((altdefault)
+         ;; Like default, but brevis is drawn with double vertical lines
+         (if (= log -1)
+             (string-append (number->string log) "double")
+             (number->string log)))
+        ((mensural)
+         (string-append (number->string log) (symbol->string style)))
+        ((petrucci)
+         (if (< log 0)
+             (string-append (number->string log) "mensural")
+             (string-append (number->string log) (symbol->string style))))
+        ((blackpetrucci)
+         (if (< log 0)
+             (string-append (number->string log) "blackmensural")
+             (string-append (number->string log) (symbol->string style))))
+        ((semipetrucci)
+         (if (< log 0)
+             (string-append (number->string log) "semimensural")
+             (string-append (number->string log) "petrucci")))
+        ((neomensural)
+         (string-append (number->string log) (symbol->string style)))
+        ((kievan)
+         (string-append (number->string log) "kievan"))
+        (else
+         (if (string-match "vaticana*|hufnagel*|medicaea*"
+                           (symbol->string style))
+             (symbol->string style)
+             (string-append (number->string (max 0 log))
+                            (symbol->string style)))))
+      ;; 'vaticana-ligature-interface has a 'glyph-name-property for NoteHead.
+      ;; Probably best to return an empty list here, if called in a context
+      ;; without setting 'style, i.e. 'style is '(), to avoid a scheme-error.
+      '()))
 
 (define-public (note-head::calc-glyph-name grob)
   (let* ((style (ly:grob-property grob 'style))
-         (log (if (string-match "kievan*" (symbol->string style))
+         (log (if (and (symbol? style)
+                       (string-match "kievan*" (symbol->string style)))
                   (min 3 (ly:grob-property grob 'duration-log))
                   (min 2 (ly:grob-property grob 'duration-log)))))
     (select-head-glyph style log)))
-- 
2.39.2