(Fface_attribute_relative_p, Fmerge_face_attribute): Handle

	Qignore_defface as a possible value.

src/ChangeLog

@@ -3,9 +3,10 @@
 	* xfaces.c (Qignore_defface): New variable.
 	(syms_of_xfaces): Provide `:ignore-defface'.
 	(IGNORE_DEFFACE_P): New macro.
-	(check_lface_attrs): Qignore_defface is a possible value.
-	(lface_fully_specified_p): Likewise.
-	(Finternal_set_lisp_face_attribute): Likewise.
+	(check_lface_attrs, lface_fully_specified_p)
+	(Finternal_set_lisp_face_attribute)
+	(Fface_attribute_relative_p, Fmerge_face_attribute): Handle
+	Qignore_defface as a possible value.
 	(merge_face_vectors): The merged face is `unspecified' if the
 	mergee specifies `:ignore-defface'.

src/xfaces.c

@@ -4794,7 +4794,7 @@ DEFUN ("face-attribute-relative-p", Fface_attribute_relative_p,
      (attribute, value)
      Lisp_Object attribute, value;
 {
-  if (EQ (value, Qunspecified))
+  if (EQ (value, Qunspecified) || (EQ (value, Qignore_defface)))
     return Qt;
   else if (EQ (attribute, QCheight))
     return INTEGERP (value) ? Qnil : Qt;
@@ -4810,7 +4810,7 @@ the result will be absolute, otherwise it will be relative.  */)
      (attribute, value1, value2)
      Lisp_Object attribute, value1, value2;
 {
-  if (EQ (value1, Qunspecified))
+  if (EQ (value1, Qunspecified) || EQ (value1, Qignore_defface))
     return value2;
   else if (EQ (attribute, QCheight))
     return merge_face_heights (value1, value2, value1);