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.
Ever since 149594f974 (Initial revision, 2005-09-20), we move the
cursor to the end of the commandline just before executing it.
This is so we can move the cursor to the line below the command line,
so moving the cursor is relevant if one presses enter on say, the
first line of a multi-line commandline.
As mentioned in #10838 and others, it can be useful to restore the
cursor position when recalling commandline from history. Make undo
restore the position where enter was pressed, instead of implicitly
moving the cursor to the end. This allows to quickly correct small
mistakes in large commandlines that failed recently.
This requires a new way of moving the cursor below the command line.
Test changes include unrelated cleanup of history.py.
