Can't access property "scrollHeight" of null #43
Description
We're are seeing a fair number of errors happening on this line in EngagementManager. Unfortunately I have been unable to reproduce this in any sensible way but somehow this is repeatedly running when doc.body is null.
One naive way to reproduce this error is go to a page, delete the body, and then scroll. This is obviously highly contrived but it proves the point that the condition is at least possible in principle. I suspect what is happening is that under some conditions the body is getting removed and completely rewritten, possibly by React or possibly by a browser extension.
We are seeing this happen in:
Next 15.5.10
Windows >= 10
Chrome 138-144
As far as I can tell this error is harmless but it does make for noisy logs. Since there is already a guard in place checking for doc I think it would be sensible to add a check also for doc.body