Imported Upstream version 2.18.0

[lilypond.git] / lily / beam-engraver.cc

diff --git a/lily/beam-engraver.cc b/lily/beam-engraver.cc
index a89435de6871a6ff391ac34075cea7e3c3f44527..846e4a245c6d772cb7ec5097fbfe80a626bf33a0 100644 (file)
--- a/lily/beam-engraver.cc
+++ b/lily/beam-engraver.cc
@@ -30,6 +30,7 @@
 #include "spanner.hh"
 #include "stream-event.hh"
 #include "stem.hh"
+#include "unpure-pure-container.hh"
 #include "warn.hh"
 
 #include "translator.icc"
@@ -176,14 +177,18 @@ Beam_engraver::typeset_beam ()
 {
   if (finished_beam_)
     {
-      if (!finished_beam_->get_bound (RIGHT))
-        finished_beam_->set_bound (RIGHT, finished_beam_->get_bound (LEFT));
-      if (forced_direction_)
+      Grob *stem = finished_beam_->get_bound (RIGHT);
+      if (!stem)
         {
-          Grob *stem = finished_beam_->get_bound (RIGHT);
-          set_grob_direction (stem, forced_direction_);
-          forced_direction_ = CENTER;
+          stem = finished_beam_->get_bound (LEFT);
+          if (stem)
+            finished_beam_->set_bound (RIGHT, stem);
         }
+
+      if (stem && forced_direction_)
+        set_grob_direction (stem, forced_direction_);
+
+      forced_direction_ = CENTER;
       finished_beam_info_->beamify (finished_beaming_options_);
 
       Beam::set_beaming (finished_beam_, finished_beam_info_);
@@ -243,7 +248,10 @@ Beam_engraver::acknowledge_rest (Grob_info info)
   if (beam_
       && !scm_is_number (info.grob ()->get_property_data ("staff-position")))
     chain_offset_callback (info.grob (),
-                           Beam::rest_collision_callback_proc, Y_AXIS);
+                           ly_make_unpure_pure_container
+                             (Beam::rest_collision_callback_proc,
+                              Beam::pure_rest_collision_callback_proc),
+                           Y_AXIS);
 }
 
 void
@@ -256,6 +264,14 @@ Beam_engraver::acknowledge_stem (Grob_info info)
   if (!valid_start_point ())
     return;
 
+  // It's suboptimal that we don't support callbacks returning ##f,
+  // but this makes beams have no effect on "stems" reliably in
+  // TabStaff when \tabFullNotation is switched off: the real stencil
+  // callback for beams is called quite late in the process, and we
+  // don't want to trigger it early.
+  if (scm_is_false (beam_->get_property_data ("stencil")))
+    return;
+
   Item *stem = dynamic_cast<Item *> (info.grob ());
   if (Stem::get_beam (stem))
     return;