Issue 4028: Automatic beaming of grace notes inhibits beam subdivision

While the whole extend_mom_ logic seems rather fishy to me (it probably
should be reset to a sane value at some other location per-beam) and
I don't have an actual idea why the Grace_auto_beam_engraver would
be involved at all here, initializing extend_mom_ to a value before
all grace notes seems to do the trick for this report.

diff --git a/lily/auto-beam-engraver.cc b/lily/auto-beam-engraver.cc
index c48fe6fe338ce061a09aca899107c85407b532c3..d9a3dd8ff62e5d45483af0a5819924338b35a388 100644 (file)
--- a/lily/auto-beam-engraver.cc
+++ b/lily/auto-beam-engraver.cc
@@ -153,6 +153,7 @@ Auto_beam_engraver::Auto_beam_engraver ()
   process_acknowledged_count_ = 0;
   stems_ = 0;
   shortest_mom_ = Moment (Rational (1, 4));
+  extend_mom_ = Moment (-1);
   finished_beam_ = 0;
   finished_grouping_ = 0;
   grouping_ = 0;