#4753 make select-head-glyph and note-head::calc-glyph-name more robust

[Thomas Morley]

make select-head-glyph and note-head::calc-glyph-name more robust

In case style is not a symbol.
A TODO is inserted, not sure how to deal with.

http://codereview.appspot.com/282270043

[Anonymous]

Passes make, make check and a full make doc

[Thomas Morley]

comments improved

http://codereview.appspot.com/282270043

[Thomas Morley]

Here a code-example, which triggered the problem:

\version "2.19.35"
{
  \override NoteHead.after-line-breaking =
    #(lambda (grob) (ly:grob-property grob 'glyph-name))
  c''1
}

returned:

/home/hermann/lilypond/usr/share/lilypond/current/scm/output-lib.scm:374:43: In procedure symbol->string in expression (symbol->string style):
/home/hermann/lilypond/usr/share/lilypond/current/scm/output-lib.scm:374:43: Wrong type argument in position 1 (expecting symbol): ()

[Anonymous]

Passes make, make check and a full make doc

[Anonymous]

Patch on countdown for January.30th

[Anonymous]

Patch counted down - please push.

[Thomas Morley]

pushed to staging as

commit 5b2517c7f542a333fdfbfe9e0f15d2ac8fc4d8d1
Author: Thomas Morley thomasmorley65@gmail.com
Date: Mon Jan 25 00:53:34 2016 +0100

make select-head-glyph and note-head::calc-glyph-name more robust

Issue 4753

In case style is not a symbol.