Merge branch 'master' of ssh+git://hanwen@git.sv.gnu.org/srv/git/lilypond

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

diff --git a/lily/context-property.cc b/lily/context-property.cc
index 81bb7c588175d56a0ddb5122320e026d53815479..5234d1113fccc00ccd1b9421697609bb72ea5f13 100644 (file)
--- a/lily/context-property.cc
+++ b/lily/context-property.cc
@@ -16,33 +16,6 @@
 #include "spanner.hh"
 #include "warn.hh"
 
-/*
-  copy ALIST leaving out SYMBOL. Copying stops at ALIST_END
-*/
-SCM
-evict_from_alist (SCM symbol,
-                 SCM alist,
-                 SCM alist_end)
-{
-  SCM new_alist = SCM_EOL;
-  SCM *tail = &new_alist;
-
-  while (alist != alist_end)
-    {
-      if (ly_is_equal (scm_caar (alist), symbol))
-       {
-         alist = scm_cdr (alist);
-         break;
-       }
-
-      *tail = scm_cons (scm_car (alist), SCM_EOL);
-      tail = SCM_CDRLOC (*tail);
-      alist = scm_cdr (alist);
-    }
-
-  *tail = alist;
-  return new_alist;
-}
 
 void
 general_pushpop_property (Context *context,
@@ -108,8 +81,9 @@ execute_override_property (Context *context,
       return;
     }
 
-  SCM symbol = scm_car (grob_property_path);
   SCM target_alist = scm_car (current_context_val);
+
+  SCM symbol = scm_car (grob_property_path);
   if (scm_is_pair (scm_cdr (grob_property_path)))
     {
       new_value = nested_property_alist (ly_assoc_get (symbol, target_alist, 
@@ -118,10 +92,10 @@ execute_override_property (Context *context,
                                         new_value);
     }
 
-  if (scm_is_pair (target_alist)
-      && scm_caar (target_alist) == symbol)
-    target_alist = scm_cdr (target_alist);
-
+  // it's tempting to replace the head of the list if it's the same
+  // property. However, we have to keep this info around, in case we have to
+  // \revert back to it.
+  
   target_alist = scm_acons (symbol, new_value, target_alist);
 
   bool ok = true;
@@ -141,7 +115,11 @@ execute_override_property (Context *context,
     }
 }
 
-         
+void
+execute_revert_property (Context *context,
+                        SCM context_property,
+                        SCM grob_property_path);
+
 void
 execute_general_pushpop_property (Context *context,
                                  SCM context_property,
@@ -150,21 +128,26 @@ execute_general_pushpop_property (Context *context,
                                  )
 {
   if (new_value != SCM_UNDEFINED)
-    {
-      execute_override_property (context, context_property,
-                                grob_property_path,
-                                new_value);
-
-      return;
-    }
+    execute_override_property (context, context_property,
+                              grob_property_path,
+                              new_value);
+  else
+    execute_revert_property (context, context_property,
+                            grob_property_path);
+}
 
+void
+execute_revert_property (Context *context,
+                        SCM context_property,
+                        SCM grob_property_path)
+{
   /*
     revert.
-   */
+  */
   SCM current_context_val = SCM_EOL;
   if (context->where_defined (context_property, &current_context_val) == context)
     {
-      SCM current_value = scm_car (current_context_val);
+      SCM current_alist = scm_car (current_context_val);
       SCM daddy = scm_cdr (current_context_val);
 
       if (!scm_is_pair (grob_property_path)
@@ -175,12 +158,29 @@ execute_general_pushpop_property (Context *context,
        }
       
       SCM symbol = scm_car (grob_property_path);
-      SCM new_alist = evict_from_alist (symbol, current_value, daddy);
 
-      if (new_alist == daddy)
-       context->unset_property (context_property);
+      if (scm_is_pair (scm_cdr (grob_property_path)))
+       {
+         SCM current_sub_alist = ly_assoc_get (symbol, current_alist, SCM_EOL);
+         SCM new_val = nested_property_revert_alist (current_sub_alist, scm_cdr (grob_property_path));
+           
+         if (scm_is_pair (current_alist)
+             && scm_caar (current_alist) == symbol
+             && current_alist != daddy)
+           current_alist = scm_cdr (current_alist);
+
+         current_alist = scm_acons (symbol, new_val, current_alist);
+         scm_set_car_x (current_context_val, current_alist);
+       }
       else
-       context->set_property (context_property, scm_cons (new_alist, daddy));
+       {
+         SCM new_alist = evict_from_alist (symbol, current_alist, daddy);
+         
+         if (new_alist == daddy)
+           context->unset_property (context_property);
+         else
+           context->set_property (context_property, scm_cons (new_alist, daddy));
+       }
     }
 }