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

[Leo]

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.


diff --git a/lisp/eshell/em-hist.el b/lisp/eshell/em-hist.el
index 45fe050..defaf5a 100644
--- a/lisp/eshell/em-hist.el
+++ b/lisp/eshell/em-hist.el
@@ -837,6 +837,8 @@ With prefix argument N, search for Nth previous match.
 If N is negative, find the next or Nth next match."
   (interactive (eshell-regexp-arg "Previous input matching (regexp): "))
   (setq arg (eshell-search-arg arg))
+  (assert (<= eshell-last-output-end (point))
+         nil "Point not located after prompt")
   (let ((pos (eshell-previous-matching-input-string-position regexp arg)))
     ;; Has a match been found?
     (if (null pos)