Fix issue 542: Harden Grob::relative_coordinate()

[lilypond.git] / lily / grob.cc

diff --git a/lily/grob.cc b/lily/grob.cc
index 18cb6280d3b840b5f0b67820806dd0d2af5f9043..7f78b5ff60112937bc5745106da7e2b96535fcab 100644 (file)
--- a/lily/grob.cc
+++ b/lily/grob.cc
@@ -265,7 +265,8 @@ Grob::translate_axis (Real y, Axis a)
 Real
 Grob::relative_coordinate (Grob const *refp, Axis a) const
 {
-  if (refp == this)
+  /* eaa - hmmm, should we do a programming_error() here? */
+  if ((this == NULL) || (refp == this))
     return 0.0;
 
   /* We catch PARENT_L_ == nil case with this, but we crash if we did
@@ -288,16 +289,23 @@ Grob::pure_relative_y_coordinate (Grob const *refp, int start, int end)
   Real off = 0;
 
   if (dim_cache_[Y_AXIS].offset_)
-    off = *dim_cache_[Y_AXIS].offset_;
+    {
+      if (to_boolean (get_property ("pure-Y-offset-in-progress")))
+       programming_error ("cyclic chain in pure-Y-offset callbacks");
+
+      off = *dim_cache_[Y_AXIS].offset_;
+    }
   else
     {
       SCM proc = get_property_data ("Y-offset");
 
       dim_cache_[Y_AXIS].offset_ = new Real (0.0);
+      set_property ("pure-Y-offset-in-progress", SCM_BOOL_T);
       off = robust_scm2double (call_pure_function (proc,
                                                   scm_list_1 (self_scm ()),
                                                   start, end),
                               0.0);
+      del_property ("pure-Y-offset-in-progress");
       delete dim_cache_[Y_AXIS].offset_;
       dim_cache_[Y_AXIS].offset_ = 0;
     }
@@ -433,7 +441,8 @@ Grob::pure_height (Grob *refp, int start, int end)
   if (!iv.is_empty () && is_number_pair (min_ext))
     iv.unite (ly_scm2interval (min_ext));
 
-  iv.translate (offset);
+  if (!iv.is_empty ())
+    iv.translate (offset);
   return iv;
 }
 
@@ -446,7 +455,7 @@ Grob::maybe_pure_extent (Grob *refp, Axis a, bool pure, int start, int end)
 }
 
 Interval_t<int>
-Grob::spanned_rank_iv () const
+Grob::spanned_rank_interval () const
 {
   return Interval_t<int> (-1, 0);
 }
@@ -625,6 +634,7 @@ ADD_INTERFACE (Grob,
               "outside-staff-horizontal-padding "
               "outside-staff-padding "
               "outside-staff-priority "
+              "pure-Y-offset-in-progress "
               "rotation "
               "springs-and-rods "
               "staff-symbol "