User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:2.0b10pre) Gecko/20110125 Firefox/4.0b10pre Build Identifier: Built from http://hg.mozilla.org/mozilla-central/rev/6a097e294828 The attached javascript code fails in the Fx 4 trunk with "Range is not a constructor" when prior to 25/1/2011 it would run successfully. Reproducible: Always Steps to Reproduce: 1. Open the test case and click the button 2. Note the lack of any alert message and the messages in the error console 3. Actual Results: In step 2, no alert is shown and the error console contains this error Error: Range is not a constructor Source File: file:///C:/Temp/test.html Line: 17 Expected Results: In step 2, an alert "r.getValue()=123" should be shown and there should be no errors in the console. In my full app I sometimes see a different error but I have not been able to reproduce that in a reduced test case. Error: can't redefine non-configurable property 'Range' Source File: http://147.149.196.167:61002/BPTMPresentation/slider/js/range.js Line: 33

Regression window(m-c hourly): Works: http://hg.mozilla.org/mozilla-central/rev/fa9577c17daf Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b10pre) Gecko/20110124 Firefox/4.0b10pre ID:20110124194331 Fails: http://hg.mozilla.org/mozilla-central/rev/7ee91bd90e7a Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b10pre) Gecko/20110124 Firefox/4.0b10pre ID:20110124195551 Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=fa9577c17daf&tochange=7ee91bd90e7a Regression window(TM hourly): Works: http://hg.mozilla.org/tracemonkey/rev/a4b72ddb9e6e Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b10pre) Gecko/20110121 Firefox/4.0b10pre ID:20110122143256 Fails: http://hg.mozilla.org/tracemonkey/rev/e8753473cdff Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b10pre) Gecko/20110121 Firefox/4.0b10pre ID:20110122155416 Pushlog: http://hg.mozilla.org/tracemonkey/pushloghtml?fromchange=a4b72ddb9e6e&tochange=e8753473cdff Candidate: e4d449cdd3be Jeff Walden — Bug 577325 - Implement function definition per ES5 plus errata (still with support for our extensions, of course). r=igor

This looks like the same issue as bug 628612. Can you please confirm that this is fixed in today's nightly?

It's working on this version Built from http://hg.mozilla.org/mozilla-central/rev/e0fc18b3bc41