bug#27405: 25.2; Make eshell-next-prompt more reliable

[npostavs]

Pierre Neidhardt <ambrevar@gmail.com> writes:

>> >    (defun eshell-previous-prompt (n)
>> >      "Move to end of Nth previous prompt in the buffer.
>> >    See `eshell-prompt-regexp'."
>> >      (interactive "p")
>> >      (backward-char)
>> >      (eshell-next-prompt (- n))))
>>
>> What's the backward-char for?
>
> That would have definitely deserved a comment...
>
> Without it, if point is right after the prompt, it won't move. That would be
> disturbing for the user.

Hmm, maybe beginning-of-line would make more sense?  If I have point on
the same line of the prompt I can get to the beginning of the prompted
line with C-a, so C-c C-p probably means I want to go farther back.