Index: src/textprop.c
===================================================================
RCS file: /cvsroot/emacs/emacs/src/textprop.c,v
retrieving revision 1.127
diff -u -d -r1.127 textprop.c
--- src/textprop.c	29 Apr 2002 19:29:58 -0000	1.127
+++ src/textprop.c	30 May 2002 22:40:44 -0000
@@ -70,6 +70,7 @@
 
 Lisp_Object Vinhibit_point_motion_hooks;
 Lisp_Object Vdefault_text_properties;
+Lisp_Object Vchar_property_alternatives_alist;
 Lisp_Object Vtext_property_default_nonsticky;
 
 /* verify_interval_modification saves insertion hooks here
@@ -2176,6 +2177,15 @@
 The value of a property in this list is seen as the value for every
 character that does not have its own value for that property.  */);
   Vdefault_text_properties = Qnil;
+
+  DEFVAR_LISP ("char-property-alternatives-alist", &Vchar_property_alternatives_alist,
+	       doc: /* Alist of alternative properties for properties without a value.
+Each element should look like (PROPERTY ALTERNATIVE1 ALTERNATIVE2...).
+If a piece of text has no direct value for a particular property, then
+this alist is consulted.  If that property appears in the alist, then
+the first non-nil value from the associated alternative properties is
+returned. */);
+  Vchar_property_alternatives_alist = Qnil;
 
   DEFVAR_LISP ("inhibit-point-motion-hooks", &Vinhibit_point_motion_hooks,
 	       doc: /* If non-nil, don't run `point-left' and `point-entered' text properties.
Index: src/intervals.h
===================================================================
RCS file: /cvsroot/emacs/emacs/src/intervals.h,v
retrieving revision 1.48
diff -u -d -r1.48 intervals.h
--- src/intervals.h	14 Mar 2002 08:09:59 -0000	1.48
+++ src/intervals.h	30 May 2002 22:40:44 -0000
@@ -267,6 +267,7 @@
 
 extern Lisp_Object Vinhibit_point_motion_hooks;
 extern Lisp_Object Vdefault_text_properties;
+extern Lisp_Object Vchar_property_alternatives_alist;
 extern Lisp_Object Vtext_property_default_nonsticky;
 
 /* Sticky properties */
Index: src/intervals.c
===================================================================
RCS file: /cvsroot/emacs/emacs/src/intervals.c,v
retrieving revision 1.113
diff -u -d -r1.113 intervals.c
--- src/intervals.c	14 Mar 2002 08:11:46 -0000	1.113
+++ src/intervals.c	30 May 2002 22:40:44 -0000
@@ -1813,8 +1813,7 @@
      Lisp_Object plist;
      register Lisp_Object prop;
 {
-  register Lisp_Object tail, fallback;
-  fallback = Qnil;
+  register Lisp_Object tail, fallback = Qnil;
 
   for (tail = plist; !NILP (tail); tail = Fcdr (Fcdr (tail)))
     {
@@ -1834,7 +1833,18 @@
     return fallback;
   if (CONSP (Vdefault_text_properties))
     return Fplist_get (Vdefault_text_properties, prop);
-  return Qnil;
+  /* Check for alternative properties */
+  tail = Fassq (prop, Vchar_property_alternatives_alist);
+  if (NILP (tail))
+    return tail;
+  tail = XCDR (tail);
+  for (; NILP (fallback) && !NILP (tail); tail = XCDR (tail))
+    {
+      if (!CONSP (tail))
+	wrong_type_argument (Qlistp, tail);
+      fallback = Fplist_get (plist, XCAR (tail));
+    }
+  return fallback;
 }