third patch from Joe: avoid NaN with springs of zero length

1 files changed, 6 insertions, 1 deletions

diff --git a/lily/simple-spacer.cc b/lily/simple-spacer.cc
index 9129361cbd..4da2ac9a87 100644
--- a/lily/simple-spacer.cc
+++ b/lily/simple-spacer.cc
@@ -105,7 +105,12 @@ Simple_spacer::add_rod (int l, int r, Real dist)
       Real spring_dist = range_ideal_len (l, r);
       if (spring_dist < dist)
 	for (int i = l; i < r; i++)
-	  springs_[i].set_distance (springs_[i].distance () * dist / spring_dist);
+	  {
+	    if (spring_dist)
+	      springs_[i].set_distance (springs_[i].distance () * dist / spring_dist);
+	    else
+	      springs_[i].set_distance (dist / (r - l));
+	  }
 
       return;
     }