Height scaling still has some issues

[marijnh]

When scrolling to the middle of https://codemirror.net/6/examples/million/, putting the cursor there and doing select-all shows some shifting in the vertical position of the text. Probably something to do with the extra viewports created for the selection endpoints.

[thomas992]

https://imgur.com/9zr3Oe4
pay attention to how the line above the selected line changes when I do select all
https://imgur.com/ezuAr27
there is the first cm-line that was not there before!
https://imgur.com/JwSxbBA
you can see the doctype tag

[thomas992]

lines with content editable false have their height attribute change slightly between selected and not selected