X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fstem.cc;h=7037b8869cdb2c59f9e4a356e5de3622bee704c1;hb=9c4a0f50b2fdad7d4d682eb07e3b408d64be9c22;hp=47e679712519e198cbc295763c3009cd17706d88;hpb=c833f8a341b81466e084ed031362eadeb4a815aa;p=lilypond.git

diff --git a/lily/stem.cc b/lily/stem.cc
index 47e6797125..7037b8869c 100644
--- a/lily/stem.cc
+++ b/lily/stem.cc
@@ -225,8 +225,7 @@ Stem::extremal_heads (Grob *me)
       Grob *n = heads[i];
       int p = Staff_symbol_referencer::get_rounded_position (n);
 
-      Direction d = LEFT;
-      do
+      for (LEFT_and_RIGHT (d))
         {
           if (d * p > d * extpos[d])
             {
@@ -234,7 +233,6 @@ Stem::extremal_heads (Grob *me)
               extpos[d] = p;
             }
         }
-      while (flip (&d) != DOWN);
     }
   return exthead;
 }
@@ -319,10 +317,8 @@ Stem::internal_pure_height (Grob *me, bool calc_beam)
     {
       Interval overshoot;
       Direction dir = get_grob_direction (me);
-      Direction d = DOWN;
-      do
+      for (DOWN_and_UP (d))
         overshoot[d] = d == dir ? dir * infinity_f : iv[d];
-      while (flip (&d) != DOWN);
 
       vector<Interval> heights;
       vector<Grob *> my_stems;
@@ -370,10 +366,8 @@ Stem::cache_pure_height (Grob *me, Interval iv, Interval my_iv)
 {
   Interval overshoot;
   Direction dir = get_grob_direction (me);
-  Direction d = DOWN;
-  do
+  for (DOWN_and_UP (d))
     overshoot[d] = d == dir ? dir * infinity_f : my_iv[d];
-  while (flip (&d) != DOWN);
 
   iv.intersect (overshoot);
   dynamic_cast<Item *> (me)->cache_pure_height (iv);
@@ -551,7 +545,8 @@ Stem::calc_positioning_done (SCM smob)
           = hed->extent (hed, X_AXIS).linear_combination (CENTER)
             - heads[i]->extent (heads[i], X_AXIS).linear_combination (CENTER);
 
-      heads[i]->translate_axis (amount, X_AXIS);
+      if (!isnan (amount)) // empty heads can produce NaN
+        heads[i]->translate_axis (amount, X_AXIS);
     }
   bool parity = true;
   Real lastpos = Real (Staff_symbol_referencer::get_position (heads[0]));
@@ -695,7 +690,7 @@ Interval
 Stem::internal_height (Grob *me, bool calc_beam)
 {
   Grob *beam = get_beam (me);
-  if (!is_valid_stem (me) && ! beam)
+  if (!is_valid_stem (me) && !beam)
     return Interval ();
 
   Direction dir = get_grob_direction (me);
@@ -706,6 +701,13 @@ Stem::internal_height (Grob *me, bool calc_beam)
       (void) beam->get_property ("quantized-positions");
     }
 
+  /*
+    If there is a beam but no stem, slope calculations depend on this
+    routine to return where the stem end /would/ be.
+  */
+  if (calc_beam && !beam && !unsmob_stencil (me->get_property ("stencil")))
+    return Interval ();
+
   Real y1 = robust_scm2double ((calc_beam
                                 ? me->get_property ("stem-begin-position")
                                 : me->get_pure_property ("stem-begin-position", 0, INT_MAX)),
@@ -793,7 +795,8 @@ Stem::internal_calc_stem_begin_position (Grob *me, bool calc_beam)
       Real y_attach = Note_head::stem_attachment_coordinate (head, Y_AXIS);
 
       y_attach = head_height.linear_combination (y_attach);
-      pos += d * y_attach * 2 / ss;
+      if (!isinf (y_attach) && !isnan (y_attach)) // empty heads
+        pos += d * y_attach * 2 / ss;
     }
 
   return pos;
@@ -881,7 +884,7 @@ Stem::offset_callback (SCM smob)
 
       Direction d = get_grob_direction (me);
       Real real_attach = head_wid.linear_combination (d * attach);
-      Real r = real_attach;
+      Real r = isnan(real_attach)? 0.0: real_attach;
 
       /* If not centered: correct for stem thickness.  */
       string style = robust_symbol2string (f->get_property ("style"), "default");