bug#31326: 27.0.50; eshell/clear exceeds max-lisp-eval-depth

bug#31326: 27.0.50; eshell/clear exceeds max-lisp-eval-depth

[Jonathan Kyle Mitchell]

The eshell/clear elisp function seems to go into an infinite loop before
ending in an error when the eshell smart display functionality is
enabled in eshell-mode-hook. Several "Error during redisplay" messages
are printed to *Messages* buffer.

Steps to reproduce:
1. ./emacs -Q
2. In the scratch buffer evaluate:
(require 'em-smart)
(add-hook 'eshell-mode-hook 'eshell-smart-initialize)
4. M-x eshell
5. type "clear" in eshell and press RET

In GNU Emacs 27.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.22.30)
of 2018-04-29 built on jkmlaptop
Repository revision: bf12cc6c7830937b4c1a3df46294e74bea749a5f
Windowing system distributor 'The X.Org Foundation', version 11.0.11906000
System Description: Ubuntu 18.04 LTS

Recent messages:
Error during redisplay: (eval (if (frame-parameter nil 'client) "@" "")) 
signaled (error "Lisp nesting exceeds ‘max-lisp-eval-depth’")
Error during redisplay: (eval (unless (display-graphic-p) "-%-")) 
signaled (error "Lisp nesting exceeds ‘max-lisp-eval-depth’")
Error during redisplay: (#[128 "\300\301\x02\"\210\300\302\x02\"\207" [apply 
redisplay--pre-redisplay-functions ignore nil] 4 nil nil] (#<window 3 on 
*eshell*>)) signaled (error "Lisp nesting exceeds ‘max-lisp-eval-depth’")
Error during redisplay: (mode-line-default-help-echo #<window 3 on 
*eshell*>) signaled (error "Lisp nesting exceeds ‘max-lisp-eval-depth’")
Error during redisplay: (eval (if (display-graphic-p) " " "-")) signaled 
(error "Lisp nesting exceeds ‘max-lisp-eval-depth’")
Error during redisplay: (eval (mode-line-eol-desc)) signaled (error 
"Lisp nesting exceeds ‘max-lisp-eval-depth’")
Error during redisplay: (eval (if (frame-parameter nil 'client) "@" "")) 
signaled (error "Lisp nesting exceeds ‘max-lisp-eval-depth’")
Error during redisplay: (eval (unless (display-graphic-p) "-%-")) 
signaled (error "Lisp nesting exceeds ‘max-lisp-eval-depth’")
redisplay--pre-redisplay-functions: (error "Lisp nesting exceeds 
‘max-lisp-eval-depth’")
Mark set
Quit
Configured using:
  'configure --with-modules'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS NOTIFY
ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 MODULES THREADS LIBSYSTEMD LCMS2

Important settings:
   value of $LANG: en_US.UTF-8
   value of $XMODIFIERS: @im=ibus
   locale-coding-system: utf-8-unix

Major mode: Eshell

Minor modes in effect:
   tooltip-mode: t
   global-eldoc-mode: t
   electric-indent-mode: t
   mouse-wheel-mode: t
   tool-bar-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t
   line-number-mode: t
   transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny seq byte-opt gv
bytecomp byte-compile cconv dired dired-loaddefs format-spec rfc822 mml
mml-sec password-cache epa derived epg epg-config gnus-util rmail
rmail-loaddefs mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils em-unix em-term term disp-table easymenu
ehelp em-script em-prompt em-ls cl-loaddefs cl-lib em-hist em-pred
em-glob em-dirs em-cmpl em-basic em-banner em-alias em-smart pcomplete
comint ansi-color ring esh-var esh-cmd esh-opt esh-io esh-ext esh-proc
esh-arg esh-groups eshell esh-module esh-util esh-mode time-date
elec-pair mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar
dnd fontset image regexp-opt fringe tabulated-list replace newcomment
text-mode elisp-mode lisp-mode prog-mode register page menu-bar
rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core term/tty-colors frame cl-generic cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese composite charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray minibuffer
cl-preloaded nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote dbusbind inotify lcms2
dynamic-setting system-font-setting font-render-setting move-toolbar gtk
x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 114325 13958)
  (symbols 48 21764 1)
  (miscs 40 58 128)
  (strings 32 33419 2014)
  (string-bytes 1 930621)
  (vectors 16 17832)
  (vector-slots 8 529981 21864)
  (floats 8 61 176)
  (intervals 56 1335 0)
  (buffers 992 12))

-- 
Jonathan Kyle Mitchell

bug#31326: 27.0.50; eshell/clear exceeds max-lisp-eval-depth

[Noam Postavsky]

[-- Attachment #1: Type: text/plain, Size: 845 bytes --]

retitle 31326 eshell/clear goes into infinite loop with eshell-smart-initialize
found 31326 25
tags 31326 + confirmed
quit

Jonathan Kyle Mitchell <kyle@jonathanmitchell.org> writes:

> The eshell/clear elisp function seems to go into an infinite loop before
> ending in an error when the eshell smart display functionality is
> enabled in eshell-mode-hook. Several "Error during redisplay" messages
> are printed to *Messages* buffer.
>
> Steps to reproduce:
> 1. ./emacs -Q
> 2. In the scratch buffer evaluate:
> (require 'em-smart)
> (add-hook 'eshell-mode-hook 'eshell-smart-initialize)
> 4. M-x eshell
> 5. type "clear" in eshell and press RET

This reproduces back to 25.3; it doesn't happen in 24.5, but "clear"
seems to do nothing in that version.  I caught a backtrace (attached)
with M-x toggle-debug-on-quit and quickly hitting C-g.


[-- Attachment #2: backtrace from C-g --]
[-- Type: application/gzip, Size: 1012 bytes --]

bug#31326: 27.0.50; eshell/clear exceeds max-lisp-eval-depth

[Jonathan Kyle Mitchell]

On 05/01/2018 07:21 AM, Noam Postavsky wrote:
> retitle 31326 eshell/clear goes into infinite loop with eshell-smart-initialize
> found 31326 25
> tags 31326 + confirmed
> quit
>
> Jonathan Kyle Mitchell <kyle@jonathanmitchell.org> writes:
>
>> The eshell/clear elisp function seems to go into an infinite loop before
>> ending in an error when the eshell smart display functionality is
>> enabled in eshell-mode-hook. Several "Error during redisplay" messages
>> are printed to *Messages* buffer.
>>
>> Steps to reproduce:
>> 1. ./emacs -Q
>> 2. In the scratch buffer evaluate:
>> (require 'em-smart)
>> (add-hook 'eshell-mode-hook 'eshell-smart-initialize)
>> 4. M-x eshell
>> 5. type "clear" in eshell and press RET
> This reproduces back to 25.3; it doesn't happen in 24.5, but "clear"
> seems to do nothing in that version.  I caught a backtrace (attached)
> with M-x toggle-debug-on-quit and quickly hitting C-g.
>

I did a little more investigation into this issue. While I don't fully 
understand all the code paths of how it works, I found that let binding 
eshell-input-filter-functions to nil stops the infinite looping.

Before issuing the clear command in eshell, 
eshell-input-filter-functions contains this list:
     (eshell-smart-display-setup eshell-add-to-history)

The original eshell/clear implementation just removes 
eshell-add-to-history, so eshell-input-filter-functions is just this 
list (which results in infinite looping):
     (eshell-smart-display-setup)

Here's a diff for the change that works for me:

diff --git a/lisp/eshell/esh-mode.el b/lisp/eshell/esh-mode.el
index bbb74c3d86..9f854c7d90 100644
--- a/lisp/eshell/esh-mode.el
+++ b/lisp/eshell/esh-mode.el
@@ -884,8 +884,7 @@ eshell/clear
    (interactive)
    (if scrollback
        (eshell/clear-scrollback)
-    (let ((eshell-input-filter-functions
-           (remq 'eshell-add-to-history eshell-input-filter-functions)))
+    (let ((eshell-input-filter-functions nil))
        (insert (make-string (window-size) ?\n))
        (eshell-send-input))))

-- 
Jonathan Kyle Mitchell

bug#31326: 27.0.50; eshell/clear exceeds max-lisp-eval-depth

[Noam Postavsky]

tags 31326 + patch
quit

Jonathan Kyle Mitchell <kyle@jonathanmitchell.org> writes:

> I did a little more investigation into this issue. While I don't fully
> understand all the code paths of how it works, I found that let
> binding eshell-input-filter-functions to nil stops the infinite
> looping.

> Here's a diff for the change that works for me:

> -    (let ((eshell-input-filter-functions
> -           (remq 'eshell-add-to-history eshell-input-filter-functions)))
> +    (let ((eshell-input-filter-functions nil))
>        (insert (make-string (window-size) ?\n))
>        (eshell-send-input))))

Makes sense, I'll push this to master in a few days.  Have you assigned
copyright for Emacs?  If no, I'll mark it as a tiny change.

bug#31326: 27.0.50; eshell/clear exceeds max-lisp-eval-depth

[Jonathan Kyle Mitchell]

On 05/04/2018 05:42 AM, Noam Postavsky wrote:
> tags 31326 + patch
> quit
>
> Jonathan Kyle Mitchell <kyle@jonathanmitchell.org> writes:
>
>> I did a little more investigation into this issue. While I don't fully
>> understand all the code paths of how it works, I found that let
>> binding eshell-input-filter-functions to nil stops the infinite
>> looping.
>> Here's a diff for the change that works for me:
>> -    (let ((eshell-input-filter-functions
>> -           (remq 'eshell-add-to-history eshell-input-filter-functions)))
>> +    (let ((eshell-input-filter-functions nil))
>>         (insert (make-string (window-size) ?\n))
>>         (eshell-send-input))))
> Makes sense, I'll push this to master in a few days.  Have you assigned
> copyright for Emacs?  If no, I'll mark it as a tiny change.
>
>

Thanks. No, I don't have any copyright papers signed. What's the process 
for doing that?

-- 
Jonathan Kyle Mitchell

bug#31326: 27.0.50; eshell/clear exceeds max-lisp-eval-depth

[Eli Zaretskii]

> From: Jonathan Kyle Mitchell <kyle@jonathanmitchell.org>
> Date: Fri, 4 May 2018 13:07:01 -0500
> Cc: 31326@debbugs.gnu.org
> 
> No, I don't have any copyright papers signed. What's the process 
> for doing that?

I can send you the instructions, if it's okay with you.

bug#31326: 27.0.50; eshell/clear exceeds max-lisp-eval-depth

[Jonathan Kyle Mitchell]

[-- Attachment #1: Type: text/plain, Size: 370 bytes --]

Yes, please do.

On Fri, May 4, 2018, 3:17 PM Eli Zaretskii <eliz@gnu.org> wrote:

> > From: Jonathan Kyle Mitchell <kyle@jonathanmitchell.org>
> > Date: Fri, 4 May 2018 13:07:01 -0500
> > Cc: 31326@debbugs.gnu.org
> >
> > No, I don't have any copyright papers signed. What's the process
> > for doing that?
>
> I can send you the instructions, if it's okay with you.
>

[-- Attachment #2: Type: text/html, Size: 824 bytes --]

bug#31326: 27.0.50; eshell/clear exceeds max-lisp-eval-depth

[Eli Zaretskii]

> From: Jonathan Kyle Mitchell <kyle@jonathanmitchell.org>
> Date: Sat, 05 May 2018 00:53:41 +0000
> Cc: Noam Postavsky <npostavs@gmail.com>, 31326@debbugs.gnu.org
> 
> Yes, please do. 

Thanks, sent off-list.

bug#31326: 27.0.50; eshell/clear exceeds max-lisp-eval-depth

[Noam Postavsky]

tags 31326 fixed
close 31326 27.1
quit

Noam Postavsky <npostavs@gmail.com> writes:

> Makes sense, I'll push this to master in a few days.

A little late, but now pushed.

[1: 39489f782e]: 2018-07-10 21:22:52 -0400
  Fix infinite recursion in eshell/clear (Bug#31326)
  https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=39489f782e436a490d1bec32d7ed9b7bcdacda24