Subject: bug#25838: 25.1; Eshell history polluted by eshell/clear

From: [email-masked]
Date: Wed, 22 Feb 2017 22:05:06 -0500

severity 25838 minor
tags 25838 patch
quit

Thomas Ferreira <[email-masked]> writes:

> In eshell:
>
> ~ $ history
> 1 history
> ~ $ eshell/clear
> [...]
> ~ $
> [...]
> ~ $ history
> 1 history
> 2 eshell/clear
> 3 
> [...]
> 4 history
>
> An easy (dirty?) way to fix it could be override eshell-input-filter (from em-hist.el):

IMO, it should be filtering out newlines anyway, but since it is
customizable, it's not quite a satisfactory fix.  We should also disable
eshell-add-to-history while sending the `eshell/clear'ing lines:

>From 8235a5510c5e0dd8262fe1ae2960d5d03883d617 Mon Sep 17 00:00:00 2001
From: Noam Postavsky <[email-masked]>
Date: Wed, 22 Feb 2017 21:48:29 -0500
Subject: [PATCH v1] Don't record eshell/clear "command" in history (Bug#25838)

`eshell/clear' is implemented by sending a series of blank lines,
which is not a useful thing to have in the history.

* lisp/eshell/em-hist.el (eshell-input-filter-default): Use
`string-blank-p' which does check for newlines (even though newlines
have comment-end syntax, not whitespace syntax class).
* lisp/eshell/esh-mode.el (eshell/clear): Remove
`eshell-add-to-history' from `eshell-input-filter-functions' while
sending the blank lines.  This change is needed to solve the bug if
the user customizes `eshell-input-filter' to something that doesn't
filter newlines.
---
 lisp/eshell/em-hist.el  | 3 ++-
 lisp/eshell/esh-mode.el | 6 ++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/lisp/eshell/em-hist.el b/lisp/eshell/em-hist.el
index 99158c7686..5c6e629120 100644
--- a/lisp/eshell/em-hist.el
+++ b/lisp/eshell/em-hist.el
@@ -55,6 +55,7 @@
 ;;; Code:
 
 (eval-when-compile (require 'cl-lib))
+(eval-when-compile (require 'subr-x)) ; `string-blank-p'
 
 (require 'ring)
 (require 'esh-opt)
@@ -208,7 +209,7 @@ eshell-rebind-keys-alist
 (defun eshell-input-filter-default (input)
   "Do not add blank input to input history.
 Returns non-nil if INPUT is blank."
-  (not (string-match "\\`\\s-*\\'" input)))
+  (not (string-blank-p input)))
 
 (defun eshell-input-filter-initial-space (input)
   "Do not add input beginning with empty space to history.
diff --git a/lisp/eshell/esh-mode.el b/lisp/eshell/esh-mode.el
index b1195c9e1d..0fd0c18301 100644
--- a/lisp/eshell/esh-mode.el
+++ b/lisp/eshell/esh-mode.el
@@ -882,8 +882,10 @@ eshell/clear
   (interactive)
   (if scrollback
       (eshell/clear-scrollback)
-    (insert (make-string (window-size) ?\n))
-    (eshell-send-input)))
+    (let ((eshell-input-filter-functions
+           (remq 'eshell-add-to-history eshell-input-filter-functions)))
+      (insert (make-string (window-size) ?\n))
+      (eshell-send-input))))
 
 (defun eshell/clear-scrollback ()
   "Clear the scrollback content of the eshell window."
-- 
2.11.1