diff -pruN tk8.6.4.orig/unix/tkUnixRFont.c tk8.6.4/unix/tkUnixRFont.c
--- tk8.6.4.orig/unix/tkUnixRFont.c	2015-02-27 02:13:18.000000000 +0900
+++ tk8.6.4/unix/tkUnixRFont.c	2015-06-10 14:35:20.639365954 +0900
@@ -259,7 +259,7 @@ InitFont(
      */
 
     set = FcFontSort(0, pattern, FcTrue, NULL, &result);
-    if (!set) {
+    if (!set || set->nfont == 0) {
 	ckfree(fontPtr);
 	return NULL;
     }