\version "2.19.51"

\header { title = "bääh" }

#(define bääh #{ { c1^\markup "bööh" } #})
\new Staff \bääh

%%%%%%%%%%%%%%%%%%%%
%% working:
%%%%%%%%%%%%%%%%%%%%

%% toplevel markup
% \markup \center-column { "@€¶ŧ←↓→øþ" いろはにほへど ちりぬるを }

%% identifier
% bööh = { c1^\markup { "@€¶ŧ←↓→øþ" } }
% \new Staff \bööh

%% named context, with assigned lyrics
% <<
%   \new Voice = "nüüääööh" { c1*4^\markup "büüh" c }
%   \new Lyrics \lyricsto "nüüääööh" { いろはにほへど -- ちりぬるを }
% >>

#(ly:set-option 'warning-as-error #f)
#(ly:expect-warning (ly:translate-cpp-warning-scheme "Markup depth exceeds maximal value of %d; Markup: %s") 1024 'cycle-markup)
#(ly:expect-warning (ly:translate-cpp-warning-scheme "Markup depth exceeds maximal value of %d; Markup: %s") 1024 'cycleII-markup)

\header {
  texidoc = "Cyclic markup definitions should cause a warning, but
not crash LilyPond with an endless loop"
}

% A simple markup function that calls itself in a loop.
#(define-markup-command (cycle layout props m)
  (markup?)
  (interpret-markup layout props (make-cycle-markup m)))

% Two simple markup functions that call each other in a loop.
#(define-markup-command (cycleI layout props m)
  (markup?)
  (interpret-markup layout props (make-cycleII-markup m)))
#(define-markup-command (cycleII layout props m)
  (markup?)
  (interpret-markup layout props (make-cycleI-markup m)))


\markup { \cycle "a" }
\markup { \cycleI "a" }