Fix crash when output-preview-framework is missing

[lilypond.git] / lily / paper-book.cc

diff --git a/lily/paper-book.cc b/lily/paper-book.cc
index ea4424c86e777e9119f037cbb6882580a90949bc..fd519d5d751fee66e7af54d84a8f14b989c40e04 100644 (file)
--- a/lily/paper-book.cc
+++ b/lily/paper-book.cc
@@ -3,12 +3,13 @@
 
   source file of the GNU LilyPond music typesetter
 
-  (c) 2004--2008 Jan Nieuwenhuizen <janneke@gnu.org>
+  (c) 2004--2009 Jan Nieuwenhuizen <janneke@gnu.org>
 */
 
 #include "paper-book.hh"
 
 #include "grob.hh"
+#include "international.hh"
 #include "main.hh"
 #include "output-def.hh"
 #include "paper-column.hh"
@@ -128,7 +129,7 @@ Paper_book::output_aux (SCM output_channel,
 
   if (scm_is_pair (bookparts_))
     {
-      for (SCM p = scm_reverse (bookparts_); scm_is_pair (p); p = scm_cdr (p))
+      for (SCM p = bookparts_; scm_is_pair (p); p = scm_cdr (p))
        if (Paper_book *pbookpart = unsmob_paper_book (scm_car (p)))
          {
            bool is_last_part = (is_last && !scm_is_pair (scm_cdr (p)));
@@ -174,25 +175,38 @@ Paper_book::output (SCM output_channel)
 
   if (get_program_option ("print-pages"))
     {
-      SCM func = scm_c_module_lookup (mod, "output-framework");
-
-      func = scm_variable_ref (func);
-      scm_apply_0 (func, scm_list_n (output_channel,
-                                    self_scm (),
-                                    scopes,
-                                    dump_fields (),
-                                    SCM_UNDEFINED));
+      SCM framework = ly_module_lookup (mod, ly_symbol2scm ("output-framework"));
+
+      if (framework != SCM_BOOL_F)
+       {
+         SCM func = scm_variable_ref (framework);
+         scm_apply_0 (func, scm_list_n (output_channel,
+                                        self_scm (),
+                                        scopes,
+                                        dump_fields (),
+                                        SCM_UNDEFINED));
+       }
+      else
+       warning (_f ("program option -dprint-pages not supported by backend `%s'",
+                    get_output_backend_name ()));
     }
 
   if (get_program_option ("preview"))
     {
-      SCM func = scm_c_module_lookup (mod, "output-preview-framework");
-      func = scm_variable_ref (func);
-      scm_apply_0 (func, scm_list_n (output_channel,
-                                    self_scm (),
-                                    scopes,
-                                    dump_fields (),
-                                    SCM_UNDEFINED));
+      SCM framework = ly_module_lookup (mod, ly_symbol2scm ("output-preview-framework"));
+
+      if (framework != SCM_BOOL_F)
+       {
+         SCM func = scm_variable_ref (framework);
+         scm_apply_0 (func, scm_list_n (output_channel,
+                                        self_scm (),
+                                        scopes,
+                                        dump_fields (),
+                                        SCM_UNDEFINED));
+       }
+      else
+       warning (_f ("program option -dpreview not supported by backend `%s'",
+                    get_output_backend_name ()));
     }
 }
 
@@ -521,7 +535,7 @@ Paper_book::systems ()
   systems_ = SCM_EOL;
   if (scm_is_pair (bookparts_))
     {
-      for (SCM p = scm_reverse (bookparts_); scm_is_pair (p); p = scm_cdr (p))
+      for (SCM p = bookparts_; scm_is_pair (p); p = scm_cdr (p))
        if (Paper_book *pbookpart = unsmob_paper_book (scm_car (p)))
          systems_ = scm_append_x (scm_list_2 (systems_, pbookpart->systems ()));
     }
@@ -581,7 +595,7 @@ Paper_book::pages ()
   pages_ = SCM_EOL;
   if (scm_is_pair (bookparts_))
     {
-      for (SCM p = scm_reverse (bookparts_); scm_is_pair (p); p = scm_cdr (p))
+      for (SCM p = bookparts_; scm_is_pair (p); p = scm_cdr (p))
        if (Paper_book *pbookpart = unsmob_paper_book (scm_car (p)))
          pages_ = scm_append_x (scm_list_2 (pages_, pbookpart->pages ()));
     }