Fix infinite loop in Completion_heads_engraver at invalid measure position (issue...

[lilypond.git] / lily / completion-note-heads-engraver.cc

diff --git a/lily/completion-note-heads-engraver.cc b/lily/completion-note-heads-engraver.cc
index 5775ef188a17e8bbd2cd3ab45c001115a1782d77..4192b58be1a9f12696aa2faa8b9f284bdf0e5445 100644 (file)
--- a/lily/completion-note-heads-engraver.cc
+++ b/lily/completion-note-heads-engraver.cc
@@ -117,6 +117,12 @@ Completion_heads_engraver::next_moment (Rational const &note_len)
     }
 
   Moment result = *l - *e;
+  if (result < 0)
+    {
+      programming_error ("invalid measure position: "
+                         + e->to_string () + " of " + l->to_string ());
+      return 0;
+    }
   Moment const *unit = unsmob_moment (get_property ("completionUnit"));
 
   if (unit)