Gutter problem in Chrome

[MMRandy]

We started experiencing a strange problem with the ACE Editor in our web app. The line numbers would not fully rendering themselves, errors are thrown during gutter cell creation, etc. I thought the problem was related to specific machine/environment issues...but have since ruled that out when others began having the same issues. I then started digging into the problem and saw that it seems to be a problem with the dom.createElement() method in the index.js, where sometimes this function returns a null...which then gets passed down to the appendChild method during the cell.update method, which in turn blows up trying to call the this method on a null object.

In addition, I uninstalled latest stable version of Chrome to ensure it's not something specific to my machine...and then installed a bunch of different versions of Chrome...and it seems this problem manifests itself in version 54 and 55, but works fine on others. Here are the specifics.

- Does Not Work
    - Version 54.0.2840.98 stable current (64-bit)
    - Version 54.0.2840.71 stable older (64-bit)
    - Version 55.0.2883.59 beta (64-bit)
- Works
    - Version 57.0.2931.0 canary (64-bit)
    - Version 56.0.2924.3 dev (64-bit)
    - Version 53.0.2785.116 (64-bit)
    - Version 51.0.2704.106 stable older (64-bit)

Attached is an image that should capture the specifics of what I'm mentioning. Could this be a race condition when rendering a large number of cells? What would cause the dom.createElement to return null?

Lastly, to make this even harder to troubleshoot, others in the office can run the same stable version of Chrome as the others of us having this issue, and it works fine....¯_(ツ)_/¯

This is a tough one to figure out...

Thanks.

[thlorenz]

Issue with ace, please file the issue there.