release: 1.3.38

[lilypond.git] / lily / property-engraver.cc

diff --git a/lily/property-engraver.cc b/lily/property-engraver.cc
index 519ca724b3415c0221e7ac656f138d30b15c21d3..c0f2887008f22d93a14e5b5652cd9422f048e5be 100644 (file)
--- a/lily/property-engraver.cc
+++ b/lily/property-engraver.cc
@@ -50,28 +50,48 @@ Property_engraver::acknowledge_element (Score_element_info i)
     }
 }
 
+
 void
 Property_engraver::apply_properties (SCM p, Score_element *e)
 {  
   for (; gh_pair_p (p); p = gh_cdr (p))
     {
+      /*
+       Try each property in order; earlier descriptions take
+       precedence over later ones, and we don't touch elt-properties if
+       they're already set.
+      */
+      
       SCM entry = gh_car (p);
       SCM prop_sym = gh_car (entry);
       SCM type_p   = gh_cadr (entry);
-      SCM elt_prop_name = gh_caddr (entry);
+      SCM elt_prop_sym = gh_caddr (entry);
 
-      SCM preset = scm_assq(prop_sym, e->element_property_alist_);
+      SCM preset = scm_assq(elt_prop_sym, e->element_property_alist_);
       if (preset != SCM_BOOL_F)
        continue;
   
       SCM val = get_property (prop_sym);
+
+     
       if (val == SCM_UNDEFINED)
-       ;
+       ;                       // Not defined in context.
       else if (gh_apply (type_p, scm_listify (val, SCM_UNDEFINED))
-              == SCM_BOOL_T)
-       e->set_elt_property (ly_symbol2string (elt_prop_name), val);
+              == SCM_BOOL_T)   // defined and  right type: do it
+       e->set_elt_property (ly_symbol2string (elt_prop_sym), val);
       else
-       {
+ /*
+           we don't print a warning if VAL == #f, because we would
+           get lots of warnings when we restore stuff to default, eg.
+
+           slurDash = #1 [...] slurDash = ##f
+
+           should not cause "type error: slurDash expects number not
+           boolean"
+
+         */
+       if (val != SCM_BOOL_F)
+       {                       // not the right type: error message.
          SCM errport = scm_current_error_port ();
          warning (_("Wrong type for property"));
          scm_display (prop_sym, errport);
@@ -82,7 +102,6 @@ Property_engraver::apply_properties (SCM p, Score_element *e)
          scm_puts (" type: ", errport);
          scm_display (ly_type (val), errport);
          scm_puts ("\n", errport);
-           
        }
     }
 }