=== modified file 'src/font.c'
--- src/font.c	2014-03-03 19:58:20 +0000
+++ src/font.c	2014-04-01 16:23:43 +0000
@@ -2756,10 +2756,7 @@
 	    Lisp_Object copy;
 
 	    val = driver_list->driver->list (f, scratch_font_spec);
-	    if (NILP (val))
-	      val = zero_vector;
-	    else
-	      val = Fvconcat (1, &val);
+	    val = NILP (val) ? zero_vector : Fvconcat (1, &val);
 	    copy = copy_font_spec (scratch_font_spec);
 	    ASET (copy, FONT_TYPE_INDEX, driver_list->driver->type);
 	    XSETCDR (cache, Fcons (Fcons (copy, val), XCDR (cache)));
@@ -2813,6 +2810,7 @@
 	else
 	  {
 	    entity = driver_list->driver->match (f, work);
+	    entity = NILP (entity) ? zero_vector : Fvconcat (1, &entity);
 	    copy = copy_font_spec (work);
 	    ASET (copy, FONT_TYPE_INDEX, driver_list->driver->type);
 	    XSETCDR (cache, Fcons (Fcons (copy, entity), XCDR (cache)));