Fix segfault from orphaned lines code

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

diff --git a/lily/paper-book.cc b/lily/paper-book.cc
index 7a13120c6464d0f426e8d63fad05cf1d8ef56d1a..9907e56d95a16b94d1f90d0e4c040c96e9c86d2a 100644 (file)
--- a/lily/paper-book.cc
+++ b/lily/paper-book.cc
@@ -516,31 +516,34 @@ Paper_book::get_system_specs ()
                                  paper_->self_scm (),
                                  page_properties,
                                  scm_car (s));
-         Prob *ps;
-         SCM list;
-         for (list = texts ; scm_is_pair (list) ; list = scm_cdr (list))
+         Prob *first = 0;
+         Prob *last = 0;
+         for (SCM list = texts; scm_is_pair (list); list = scm_cdr (list))
            {
              SCM t = scm_car (list);
              // TODO: init props
-             ps = make_paper_system (SCM_EOL);
+             Prob *ps = make_paper_system (SCM_EOL);
              ps->set_property ("page-break-permission",
                                ly_symbol2scm ("allow"));
              ps->set_property ("page-turn-permission",
                                ly_symbol2scm ("allow"));
              ps->set_property ("last-markup-line",  SCM_BOOL_F);
-             ps->set_property ("first-markup-line",
-                         list == texts? SCM_BOOL_T : SCM_BOOL_F);
+             ps->set_property ("first-markup-line", SCM_BOOL_F);
 
              paper_system_set_stencil (ps, *unsmob_stencil (t));
              
              SCM footnotes = get_footnotes (unsmob_stencil (t)->expr ());
              ps->set_property ("footnotes", footnotes);
              ps->set_property ("is-title", SCM_BOOL_T);
-             if (list != texts)
-               /* For each markup other than the first, place it as closely as
-                  possible to the previous markup and don't allow stretching. */
-               ps->set_property ("tight-spacing", SCM_BOOL_T);
-
+             if (list == texts)
+               first = ps;
+             else
+               {
+                 // last line so far, in a multi-line paragraph
+                 last = ps;
+                 //Place closely to previous line, no stretching.
+                 ps->set_property ("tight-spacing", SCM_BOOL_T);
+               }
              system_specs = scm_cons (ps->self_scm (), system_specs);
              ps->unprotect ();
 
@@ -552,17 +555,13 @@ Paper_book::get_system_specs ()
              // FIXME: figure out penalty.
              //set_system_penalty (ps, scores_[i].header_);
            }
-         // We may want to place a check here, for whether the line is too short
-         if (list == texts)
-           {
-             // if there is only one line in the paragraph,
-             // do not try to avoid orphans
-             ps->set_property ("last-markup-line", SCM_BOOL_F);
-             ps->set_property ("first-markup-line", SCM_BOOL_F);
-           }
-         else
-           {
-             ps->set_property ("last-markup-line", SCM_BOOL_T);
+         /* Set properties to avoid widowed/orphaned lines.
+            Single-line markup_lists are excluded, but in future
+            we may want to add the case of a very short, single line. */
+         if (first && last)
+           {
+             last->set_property ("last-markup-line", SCM_BOOL_T);
+             first->set_property ("first-markup-line", SCM_BOOL_T);
            }
        }
       else