bug#7585: 23.2.90; [PATCH] fix eshell-previous-matching-input

[Stefan Monnier]

> There is a customisable variable eshell-hist-move-to-end when set to
> nil, point is not guaranteed to be located behind
> eshell-last-output-end. Thus blindly calling delete-region and
> insert-and-inherit will generate an error in that case.

The patch looks good as well, tho we usually prefer not to use `assert'
in this way (I'd keep assert for actual coding errors, so better use an
if test that then `signal's an error).


        Stefan