markup-lines.ly not failing gracefully

[Graham Percival]

Hi Nicolas,

The TOC stuff look really neat; thanks for adding it!  I have two issues:

1)  In the future, could you add examples of new features (the 
regression tests are fine) to  input/new/DIR/  ?  Don't worry about 
doing it for these three (markup-lines.ly, page-label.ly, and toc.ly), 
but in the future please do this.

2)  Running markup-lines.ly in -dsafe mode produces weird behavior.

$ lilypond -dsafe markup-lines.ly
...
markup-lines.ly:10:1: error: GUILE signaled an error for the expression 
beginning here
#
 (define-markup-list-command (paragraph layout props args) (markup-list?)
Unbound variable: define-markup-list-command
markup-lines.ly:16:2: error: unknown escaped string: `\paragraph'

  \paragraph {
markup-lines.ly:29:2: error: unknown escaped string: `\paragraph'

  \paragraph {
Finding the ideal number of pages...^C

(at this point lilypond seems to hang; after 30 seconds, I hit ctrl-c)


$ lilypond -V -dsafe markup-lines.ly
...
In unknown file:
   ?:  0* [lilypond-main ("markup-lines.ly")]
In 
/Users/gperciva/Apps/LilyPond.app/Contents/Resources/share/lilypond/current/scm/lily.scm:
 650:  1* (let* ((failed #)) (if (ly:get-option #) (begin #)) ...)
 650:  2* [lilypond-all ("markup-lines.ly")]
 667:  3  (let* ((failed #) (separate-logs #) (do-measurements #) ...) 
(gc) ...)
 674:  4* [for-each #<procedure #f (x)> ("markup-lines.ly")]
In unknown file:
   ?:  5* [#<procedure #f (x)> "markup-lines.ly"]
In 
/Users/gperciva/Apps/LilyPond.app/Contents/Resources/share/lilypond/current/scm/lily.scm:
 676:  6* (let* (# # #) (if separate-logs #) (if # #) ...)
 688:  7* [lilypond-file #<procedure #f (key failed-file)> 
"markup-lines.ly"]
 728:  8  [catch ly-file-failed #<procedure #f ()> #<procedure #f (x . 
args)>]
In unknown file:
   ?:  9* [#<procedure #f ()>]
In 
/Users/gperciva/Apps/LilyPond.app/Contents/Resources/share/lilypond/current/scm/lily.scm:
 729: 10* [ly:parse-file "markup-lines.ly"]
In markup-lines.ly:
  10: 11* (define-markup-list-command # # #)

markup-lines.ly:10:1: In expression (define-markup-list-command 
(paragraph layout props ...) (markup-list?) ...):
markup-lines.ly:10:1: Unbound variable: define-markup-list-command
$


In other words, adding -V makes the -dsafe option fail much more 
gracefully.  I'm not certain how -V and -dsafe operate internally, but 
this seems weird.

(we need to run this example through -dsafe to mark it for manual 
attention.)

Cheers,
- Graham