UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/60.0.3112.113 Chrome/60.0.3112.113 Safari/537.36

Steps to reproduce the problem:
var test = [1,2,3];
test[1] = 2;

var test2;
test2[1] = 22;

What is the expected behavior?
The first pair of lines are correct; the second will fail.
However, the error message is rather less clear than it could be. 

What went wrong?
I get the error message: "Cannot set property '1' of undefined".  

That's not as helpful as it could be, because Chrome has already de-referenced the thing that's not defined.

What would be far better is the error:
 "Cannot set property '1' of 'test2' which is undefined.

In other words, what I want to know is "there is a problem with test2, caused by it being undefined", not "there is a problem with something undefined... now you go figure out what it was that wasn't defined".

This doesn't just affect arrays.

Did this work before? No 

Chrome version: 60.0.3112.113  Channel: n/a
OS Version: Ubuntu
Flash Version: