From 8f48aae564544d143022f5ddfde5bd9fdc600bf4 Mon Sep 17 00:00:00 2001
From: David Kastrup <dak@gnu.org>
Date: Sun, 10 Jun 2012 21:16:00 +0200
Subject: [PATCH] Protect a few events from gc.

Some may not be related to obscure errors we see, but as far as I can tell,
events don't have built-in protection when sticking around after their
time.  I have really no clue how grobs are protected from collection, but
since they do not seem to get extra treatment elsewhere, I hope they'll
be fine until output time.
---
 lily/phrasing-slur-engraver.cc | 11 +++++++++++
 lily/slur-engraver.cc          | 11 +++++++++++
 lily/staff-symbol-engraver.cc  | 10 ++++++++++
 3 files changed, 32 insertions(+)

diff --git a/lily/phrasing-slur-engraver.cc b/lily/phrasing-slur-engraver.cc
index ea2439534c..9303df4f22 100644
--- a/lily/phrasing-slur-engraver.cc
+++ b/lily/phrasing-slur-engraver.cc
@@ -70,6 +70,7 @@ protected:
   void process_music ();
 
   virtual void finalize ();
+  virtual void derived_mark () const;
 
 public:
   TRANSLATOR_DECLARATIONS (Phrasing_slur_engraver);
@@ -79,6 +80,15 @@ Phrasing_slur_engraver::Phrasing_slur_engraver ()
 {
 }
 
+void
+Phrasing_slur_engraver::derived_mark () const
+{
+  for (vsize i=start_events_.size(); i--;)
+    scm_gc_mark (start_events_[i]->self_scm ());
+  for (vsize i=stop_events_.size(); i--;)
+    scm_gc_mark (stop_events_[i]->self_scm ());
+}
+
 IMPLEMENT_TRANSLATOR_LISTENER (Phrasing_slur_engraver, phrasing_slur);
 void
 Phrasing_slur_engraver::listen_phrasing_slur (Stream_event *ev)
@@ -165,6 +175,7 @@ Phrasing_slur_engraver::finalize ()
       slurs_[i]->warning (_ ("unterminated phrasing slur"));
       slurs_[i]->suicide ();
     }
+  slurs_.clear ();
 }
 
 void
diff --git a/lily/slur-engraver.cc b/lily/slur-engraver.cc
index e496285288..fde4d9447d 100644
--- a/lily/slur-engraver.cc
+++ b/lily/slur-engraver.cc
@@ -71,6 +71,7 @@ protected:
   void process_music ();
 
   virtual void finalize ();
+  virtual void derived_mark () const;
 
 public:
   TRANSLATOR_DECLARATIONS (Slur_engraver);
@@ -80,6 +81,15 @@ Slur_engraver::Slur_engraver ()
 {
 }
 
+void
+Slur_engraver::derived_mark () const
+{
+  for (vsize i=start_events_.size(); i--;)
+    scm_gc_mark (start_events_[i]->self_scm ());
+  for (vsize i=stop_events_.size(); i--;)
+    scm_gc_mark (stop_events_[i]->self_scm ());
+}
+
 IMPLEMENT_TRANSLATOR_LISTENER (Slur_engraver, slur);
 void
 Slur_engraver::listen_slur (Stream_event *ev)
@@ -166,6 +176,7 @@ Slur_engraver::finalize ()
       slurs_[i]->warning (_ ("unterminated slur"));
       slurs_[i]->suicide ();
     }
+  slurs_.clear ();
 }
 
 void
diff --git a/lily/staff-symbol-engraver.cc b/lily/staff-symbol-engraver.cc
index 509f86184a..66ee8002a7 100644
--- a/lily/staff-symbol-engraver.cc
+++ b/lily/staff-symbol-engraver.cc
@@ -46,8 +46,18 @@ protected:
   DECLARE_TRANSLATOR_LISTENER (staff_span);
   virtual void finalize ();
   void process_music ();
+  virtual void derived_mark () const;
 };
 
+void
+Staff_symbol_engraver::derived_mark () const
+{
+  for (LEFT_and_RIGHT (d)) {
+    if (span_events_[d])
+      scm_gc_mark (span_events_[d]->self_scm ());
+  }
+}
+
 Staff_symbol_engraver::~Staff_symbol_engraver ()
 {
   if (span_)
-- 
2.39.5