Odd placement of redo / undo markers.

[jordwalke]

Codemirror-vim's undo/redo markers don't match vim's and don't really make sense.

• It seems that in codemirror-vim, any newline forms an undo/redo marker.
• Also a popup window opening somehow forms an undo marker.

In these videos I am largely staying in insert mode the entire time until the end where I undo/redo.
Notice how in vim it is one exact undo/redo marker:

Comparing vim:

vim.mov

But in codemirror-vim, each newline and popup creates an undo marker.

Codemirror-vim:

codemirror.mov

I will say one nice thing that code mirror-vim does right, is it places the cursor at the start of the redone change. Hardly any other vim emulators get this right. But the breaking up of undo markers seems very different from vim's, and in the case of popups - seems like a bug.