blame says this is the offending commit: https://gerrit.wikimedia.org/r/#/c/304575/ @DLynch

Can you see what is going on here @DLynch - I couldn't quite work out what case your original code was fixing.

My code was fixing an issue most easily seen with long references containing large blocks of text. Pressing backspace in them would scroll the reference dialog all the way to the top, because of the on-backspace selection fixing code reapplying the selection.

Change 325960 had a related patch set uploaded (by DLynch):
ce.Surface showSelectionState: Avoid unnecessary refocusing

https://gerrit.wikimedia.org/r/325960

Issue was: in IE<=11, focusing an already-focused element will scroll the viewport to bring the top edge of the element into view. Other browsers skip this, if the element is already visible in the viewport. Edge brings its behavior in-line with the other browsers.

The attached patch just checks whether the currently active element is the element that would be focused, and skips doing anything if so. (Scrolling to the new selection from off-screen if the element is focused and you've scrolled away happens in all current browsers without the focus being required.)

Change 325960 merged by jenkins-bot:
ce.Surface showSelectionState: Avoid unnecessary refocusing

https://gerrit.wikimedia.org/r/325960

Change 326141 had a related patch set uploaded (by Jforrester):
Update VE core submodule to master (9be803f)

https://gerrit.wikimedia.org/r/326141

Change 326141 merged by jenkins-bot:
Update VE core submodule to master (33012af)

https://gerrit.wikimedia.org/r/326141