1 files changed, 6 insertions, 3 deletions
diff --git a/lib/js/urweb.js b/lib/js/urweb.js
index 18d47847..f41d7240 100644
--- a/lib/js/urweb.js
+++ b/lib/js/urweb.js
@@ -1498,11 +1498,14 @@ function ssidx(h, n) {
 }
 
 function sspn(s, chs) {
-    for (var i = 0; i < s.length; ++i)
-        if (chs.indexOf(s.charAt(i)) != -1)
+    var s2 = Array.from(s);
+    var chs2 = Array.from(chs);
+    
+    for (var i = 0; i < s2.length; ++i)
+        if (chs2.indexOf(s2[i]) != -1)
             return i;
 
-    return s.length;
+    return s2.length;
 }
 function schr(s, ch) {
     var r = s.indexOf(ch);