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

[Leo]

On 2010-12-13 20:42 +0000, Stefan Monnier wrote:
>> Would something like the following acceptable? Thanks. Leo
>
> No, don't use `message': this is a real error, use `signal' or `error'.
>
>
>         Stefan

OK. Here is the whole thing with the change of `message' to `error'.

Without this patch, one usually gets an error like "Text is read-only"
when M-n/p. So the error is obscure. The patch makes the error more
useful.

2010-12-13  Leo <sdl.web@gmail.com>

        * eshell/em-hist.el (eshell-previous-matching-input): Check point
        is located after eshell prompt in case `eshell-hist-move-to-end'
        is nil.

 lisp/eshell/em-hist.el |   22 ++++++++++++----------
 1 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/lisp/eshell/em-hist.el b/lisp/eshell/em-hist.el
index 45fe050..47e0b2b 100644
--- a/lisp/eshell/em-hist.el
+++ b/lisp/eshell/em-hist.el
@@ -837,16 +837,18 @@ 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))
-  (let ((pos (eshell-previous-matching-input-string-position regexp arg)))
-    ;; Has a match been found?
-    (if (null pos)
-       (error "Not found")
-      (setq eshell-history-index pos)
-      (unless (minibuffer-window-active-p (selected-window))
-       (message "History item: %d" (- (ring-length eshell-history-ring) pos)))
-       ;; Can't use kill-region as it sets this-command
-      (delete-region eshell-last-output-end (point))
-      (insert-and-inherit (eshell-get-history pos)))))
+  (if (<= eshell-last-output-end (point))
+      (let ((pos (eshell-previous-matching-input-string-position regexp arg)))
+       ;; Has a match been found?
+       (if (null pos)
+           (error "Not found")
+         (setq eshell-history-index pos)
+         (unless (minibuffer-window-active-p (selected-window))
+           (message "History item: %d" (- (ring-length eshell-history-ring) 
pos)))
+         ;; Can't use kill-region as it sets this-command
+         (delete-region eshell-last-output-end (point))
+         (insert-and-inherit (eshell-get-history pos))))
+    (error "Point not located after prompt")))
 
 (defun eshell-next-matching-input (regexp arg)
   "Search forwards through input history for match for REGEXP.
-- 
1.7.3