UserAgent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36

Steps to reproduce the problem:
1. $(old_object).attr('class', $(new_object).attr('class'));
2. 
3. 

What is the expected behavior?
by checking the DOM, class attribute of $(old_object) should be set to class attribute of $(new_object)

What went wrong?
DOM viewer shows that class attribute of $(old_object) is not changed

Did this work before? Yes 61.0.3163.79

Chrome version: 62.0.3202.62  Channel: n/a
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: 

works if use $(old_object).attr('class', 'HardCodedClassName');