[js] Fix a bug with NQPMu $!cstack breaking the bstack.

Raku · Apr 30, 2016 · a28876c · a28876c
1 parent 1daaef5
commit a28876c
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/vm/js/nqp-runtime/nfa.js b/src/vm/js/nqp-runtime/nfa.js
@@ -278,7 +278,7 @@ op.nfarunalt = function(nfa, target, pos, bstack, cstack, marks) {
   var fates = runNFA(nfa, target, pos).array;
 
   /* Push the results onto the bstack. */
-  var caps = cstack ? cstack.length : 0;
+  var caps = cstack instanceof Array ? cstack.length : 0;
 
   for (var i = 0; i < fates.length; i++) {
     bstack.push(marks[fates[i]], pos, 0, caps);