From 80c1b01f054c5d65ca96a568aaf1c28ffe97215b Mon Sep 17 00:00:00 2001
From: David Corbett <corbett.dav@husky.neu.edu>
Date: Tue, 5 Dec 2017 08:28:42 -0500
Subject: [PATCH] Allow digits in language system tags

---
 src/hb-ot-tag.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hb-ot-tag.cc b/src/hb-ot-tag.cc
index 0514c41a3..1338c3173 100644
--- a/src/hb-ot-tag.cc
+++ b/src/hb-ot-tag.cc
@@ -920,7 +920,7 @@ hb_ot_tag_from_language (hb_language_t language)
     char tag[4];
     int i;
     s += 6;
-    for (i = 0; i < 4 && ISALPHA (s[i]); i++)
+    for (i = 0; i < 4 && ISALNUM (s[i]); i++)
       tag[i] = TOUPPER (s[i]);
     if (i) {
       for (; i < 4; i++)