Re: comint-accumulate-marker

[Richard Stallman]

    Formerly only M-p, and M-n worked.  M-r/M-s could *appear* to work if
    you had already used M-p to save some partial input, but it wasn't
    current.

It is useful to make M-r and M-s work correctly in all cases.

However, adding a new command (whether it be C-c C-j or whatever)
is not appropriate now.