This feature is nice and desirable, but it was implemented in a intrusive way
by modifying the sequence of bytes we emit when running a command; this in
turn requires changing a bunch of tests.
This sequence hasn't changed in decades and the consequences of changing it
are hard to predict, given that it is likely terminal dependent; we've
already found a regression.
It's fine to reintroduce this but it should be done in a less intrusive way
(conceptually that seems straightforward - we're just remembering the cursor
position).
Revert "Fix spurious blank lines when executing scrolled commandline"
This reverts commit 0e512f8033.
Revert "On undo after execute, restore the cursor position "
This reverts commit 610338cc70.