Incorrect match.index property on RegEx

[dbogatz]

var re = /<%(.+?)%>/g, html = "<%hund%><%katze%><%maus%>", match;

 while(match = re.exec(html)) {
      console.log("index: "+match.index);
 }

Expected: index: 0 index: 8 index: 17

MuJS: index: 0 index: 0 index: 0