bug#6691: 23.2; Eshell and ^M (PATCH attached)

[Leo]

The problem is eshell-last-output-block-begin can point to a wrong
position in the eshell buffer after truncating buffer. I tried to trace
the reason of introducing eshell-last-output-block-begin but the
revision history only goes back to 2000.

It looks like cruft to me. So I propose the following fix.

Leo

commit 1f263a7a7d9d978b68006619a0d2a0d6dcbf39c1
Date:   Thu Jul 22 16:21:30 2010 +0100

    Remove cruft eshell-last-output-block-begin and fix #6691

        Modified lisp/eshell/esh-mode.el
diff --git a/lisp/eshell/esh-mode.el b/lisp/eshell/esh-mode.el
index cc7f0df..ee9b299 100644
--- a/lisp/eshell/esh-mode.el
+++ b/lisp/eshell/esh-mode.el
@@ -213,7 +213,6 @@ This is used by `eshell-watch-for-password-prompt'."
 (defvar eshell-last-input-start nil)
 (defvar eshell-last-input-end nil)
 (defvar eshell-last-output-start nil)
-(defvar eshell-last-output-block-begin nil)
 (defvar eshell-last-output-end nil)
 
 (defvar eshell-currently-handling-window nil)
@@ -381,7 +380,6 @@ This is used by `eshell-watch-for-password-prompt'."
   (set (make-local-variable 'eshell-last-input-end) (point-marker))
   (set (make-local-variable 'eshell-last-output-start) (point-marker))
   (set (make-local-variable 'eshell-last-output-end) (point-marker))
-  (set (make-local-variable 'eshell-last-output-block-begin) (point))
 
   (let ((modules-list (copy-sequence eshell-modules-list)))
     (make-local-variable 'eshell-modules-list)
@@ -611,7 +609,6 @@ If NO-HOOKS is non-nil, then `eshell-post-command-hook' 
won't be run."
   (setq eshell-last-input-start (point-marker)
        eshell-last-input-end (point-marker)
        eshell-last-output-start (point-marker)
-       eshell-last-output-block-begin (point)
        eshell-last-output-end (point-marker))
   (eshell-begin-on-new-line)
   (unless no-hooks
@@ -808,9 +805,7 @@ This is done after all necessary filtering has been done."
 (defun eshell-run-output-filters ()
   "Run the `eshell-output-filter-functions' on the current output."
   (save-current-buffer
-    (run-hooks 'eshell-output-filter-functions))
-  (setq eshell-last-output-block-begin
-       (marker-position eshell-last-output-end)))
+    (run-hooks 'eshell-output-filter-functions)))
 
 ;;; jww (1999-10-23): this needs testing
 (defun eshell-preinput-scroll-to-bottom ()
@@ -1031,7 +1026,7 @@ buffer's process if STRING contains a password prompt 
defined by
 This function could be in the list `eshell-output-filter-functions'."
   (when (eshell-interactive-process)
     (save-excursion
-      (goto-char eshell-last-output-block-begin)
+      (goto-char eshell-last-input-end)
       (beginning-of-line)
       (if (re-search-forward eshell-password-prompt-regexp
                             eshell-last-output-end t)
@@ -1044,7 +1039,7 @@ This function could be in the list 
`eshell-output-filter-functions'."
   "Act properly when certain control codes are seen."
   (save-excursion
     (let ((orig (point)))
-      (goto-char eshell-last-output-block-begin)
+      (goto-char eshell-last-input-end)
       (unless (eolp)
        (beginning-of-line))
       (while (< (point) eshell-last-output-end)