NB 17rc3 (and I think 16) code editor misbehaves sometimes after deleting lines

[Scott Palmer <sw...@gmail.com>]

Has anyone else noticed that after deleting a bunch of lines the cursor
will refuse to move beyond a certain area using just the cursor keys?
E.g. I delete a chunk of lines and then hold cursor-down (or up), but the
cursor moves a few lines and then resets back to the beginning of the area
where I deleted.  It just loops over those lines.  You can click outside
that area, but editing within that area is messed up until you do.

This doesn't seem to happen every time, but it does happen enough to be
annoying.

Scott