--- /dev/null
+var ITERATOR = require('./_wks')('iterator')
+ , SAFE_CLOSING = false;
+
+try {
+ var riter = [7][ITERATOR]();
+ riter['return'] = function(){ SAFE_CLOSING = true; };
+ Array.from(riter, function(){ throw 2; });
+} catch(e){ /* empty */ }
+
+module.exports = function(exec, skipClosing){
+ if(!skipClosing && !SAFE_CLOSING)return false;
+ var safe = false;
+ try {
+ var arr = [7]
+ , iter = arr[ITERATOR]();
+ iter.next = function(){ return {done: safe = true}; };
+ arr[ITERATOR] = function(){ return iter; };
+ exec(arr);
+ } catch(e){ /* empty */ }
+ return safe;
+};
\ No newline at end of file