Don't crash on a pending spanner in Staff_symbol_engraver dtor.

[lilypond.git] / lily / page-breaking.cc

diff --git a/lily/page-breaking.cc b/lily/page-breaking.cc
index 993bfa459256c51c10fa57cb03678a018b103983..d5f71297b8390f4219969660a39c348c45f6c22b 100644 (file)
--- a/lily/page-breaking.cc
+++ b/lily/page-breaking.cc
@@ -1,7 +1,7 @@
 /*
   This file is part of LilyPond, the GNU music typesetter.
 
-  Copyright (C) 2006--2010 Joe Neeman <joeneeman@gmail.com>
+  Copyright (C) 2006--2011 Joe Neeman <joeneeman@gmail.com>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -529,6 +529,11 @@ Page_breaking::make_pages (vector<vsize> lines_per_page, SCM systems)
       ret = scm_cons (page, ret);
       --page_num;
     }
+
+  // By reversing the table, we ensure that duplicated labels (eg. those
+  // straddling a page turn) will appear in the table with their last
+  // occurence first.
+  label_page_table = scm_reverse_x (label_page_table, SCM_EOL);
   book_->top_paper ()->set_variable (ly_symbol2scm ("label-page-table"), label_page_table);
   return ret;
 }
@@ -671,6 +676,7 @@ Page_breaking::chunk_list (vsize start_index, vsize end_index)
   return ret;
 }
 
+// Returns the minimum number of _non-title_ lines.
 vsize
 Page_breaking::min_system_count (vsize start, vsize end)
 {
@@ -683,6 +689,7 @@ Page_breaking::min_system_count (vsize start, vsize end)
   return ret;
 }
 
+// Returns the maximum number of _non-title_ lines.
 vsize
 Page_breaking::max_system_count (vsize start, vsize end)
 {
@@ -695,6 +702,9 @@ Page_breaking::max_system_count (vsize start, vsize end)
   return ret;
 }
 
+// The numbers returned by this function represent either
+// the maximum or minimum number of _non-title_ lines
+// per chunk.
 Page_breaking::Line_division
 Page_breaking::system_count_bounds (vector<Break_position> const &chunks,
                                    bool min)
@@ -702,7 +712,7 @@ Page_breaking::system_count_bounds (vector<Break_position> const &chunks,
   assert (chunks.size () >= 2);
 
   Line_division ret;
-  ret.resize (chunks.size () - 1, 1);
+  ret.resize (chunks.size () - 1, 0);
 
   for (vsize i = 0; i + 1 < chunks.size (); i++)
     {
@@ -802,7 +812,7 @@ Page_breaking::set_to_ideal_line_configuration (vsize start, vsize end)
          div.push_back (line_breaking_[sys].best_solution (start, end).size ());
        }
       else
-       div.push_back (1);
+       div.push_back (0);
 
       system_count_ += div.back ();
     }
@@ -839,7 +849,7 @@ Page_breaking::cache_line_details (vsize configuration_index)
            }
          else
            {
-             assert (div[i] == 1);
+             assert (div[i] == 0);
              uncompressed_line_details_.push_back (system_specs_[sys].prob_
                                                    ? Line_details (system_specs_[sys].prob_, book_->paper_)
                                                    : Line_details ());
@@ -877,7 +887,7 @@ Page_breaking::line_divisions_rec (vsize system_count,
   int real_min = max ((int) min_sys[my_index], (int) system_count - others_max);
   int real_max = min ((int) max_sys[my_index], (int) system_count - others_min);
 
-  if (real_min > real_max || real_min <= 0)
+  if (real_min > real_max || real_min < 0)
     {
       /* this should never happen within a recursive call. If it happens
         at all, it means that we were called with an unsolvable problem