Created attachment 8831091 [details] dosme.html User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0 Build ID: 20161208153507 Steps to reproduce: Works for me in All OS and various versions. Steps to reproduce : 1. Open http://hackies.in/dosme.html OR dosme.html attached below Click - ClickMe Browser freeze ups.
Created attachment 8831096 [details] updated_dosme.html Please ignore the attached file please use updated file for reproduce:
The testcase has 3 nested loops which loop: * 0x8964 (~35000 in decimal) times * 3 times * ~200-300 times (depending on the element) for the attributes which means we call document.write with ~ 20-odd characters 35000 * 3 * 200 = 20,000,000 times. Which means this is basically bug 380223 - you're looping through document.write and the loop increments slowly enough that you see a hang, rather than an OOM crash (which would happen if your loops were adding more elements (ie increasing memory usage) per iteration). Either way, still a dupe of 380223.