bug#35158: 26.1; Display bugs: odd bits wrong in shell window

bug#35158: 26.1; Display bugs: odd bits wrong in shell window

[DJC]

[-- Attachment #1: Type: text/plain, Size: 3558 bytes --]

In GNU Emacs 26.1 (build 1, x86_64-w64-mingw32)
  of 2018-05-30 built on CIRROCUMULUS
Repository revision: 07f8f9bc5a51f5aa94eb099f3e15fbe0c20ea1ea
Windowing system distributor 'Microsoft Corp.', version 6.1.7601
Configured using:
  'configure --without-dbus --host=x86_64-w64-mingw32
  --without-compress-install 'CFLAGS=-O2 -static -g3''

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY ACL GNUTLS LIBXML2 ZLIB
TOOLKIT_SCROLL_BARS THREADS LCMS2

Important settings:
   value of $LANG: ENU
   locale-coding-system: cp1252

Major mode: Text

Minor modes in effect:
   shell-dirtrack-mode: t
   tooltip-mode: t
   global-eldoc-mode: t
   mouse-wheel-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t
   line-number-mode: t
   auto-fill-function: do-auto-fill
   transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow mail-extr emacsbug message rmc puny dired dired-loaddefs
format-spec rfc822 mml mml-sec epa derived epg gnus-util rmail
rmail-loaddefs mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mail-utils browse-url url-util shell pcomplete rect kmacro thingatpt
iso-transl elec-pair server comint ansi-color ring mm-util mail-prsvr
subtitles pk-ispell ido trees mouseme sort app-specials html-cosmetics
sgml-mode dom html-vars html-filter html-clean-page text-cosmetics
pk_emacs finder-inf package easymenu epg-config url-handlers url-parse
auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs
password-cache url-vars seq byte-opt gv bytecomp byte-compile cconv
cl-loaddefs cl-lib time-date mule-util tooltip eldoc electric uniquify
ediff-hook vc-hooks lisp-float-type mwheel dos-w32 ls-lisp disp-table
term/w32-win w32-win w32-vars term/common-win 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 w32notify w32 lcms2 multi-tty make-network-process emacs)

In the upper window of a frame I had several hundred lines containing the 
full paths of filenames within quotation marks -- all containing non-ASCII 
accented European characters -- and in the lower window a Windows shell. 
 From the shell window I used a macro to change windows, grab a file name, 
then return to the shell window and issue

     del {filename within quotation marks}

After confirming that this was working as desired, I issued a command to 
repeat the macro indefinitely.  As lines scrolled in the shell window I 
remarked some errors in the display there: certain improper bits were being 
displayed rather consistently.  When the run was finished, I grabbed a 
screen shot of the quiescent state (attached) showing some of these. 
Scrolling lines off the bottom of the window and then back on caused them 
to redisplay properly.

djc

[-- Attachment #2: Emacs display errors.png --]
[-- Type: image/png, Size: 5859 bytes --]

bug#35158: 26.1; Display bugs: odd bits wrong in shell window

[Eli Zaretskii]

> From: DJC <djc@resiak.org>
> Date: Fri, 5 Apr 2019 16:13:24 +0200
> 
> In the upper window of a frame I had several hundred lines containing the 
> full paths of filenames within quotation marks -- all containing non-ASCII 
> accented European characters -- and in the lower window a Windows shell. 
>  From the shell window I used a macro to change windows, grab a file name, 
> then return to the shell window and issue
> 
>      del {filename within quotation marks}
> 
> After confirming that this was working as desired, I issued a command to 
> repeat the macro indefinitely.  As lines scrolled in the shell window I 
> remarked some errors in the display there: certain improper bits were being 
> displayed rather consistently.  When the run was finished, I grabbed a 
> screen shot of the quiescent state (attached) showing some of these. 

You mean, those stray pixels after "5" in "HS2015"?  And also the
artifacts before the backslashes in last two lines you captured?

If so, I suggest to review the settings of your display driver, and if
there are any "optimization" options there, turn them off.

Thanks.

bug#35158: 26.1; Display bugs: odd bits wrong in shell window

[DJC]

Thanks for the suggestion.  But as far as I can tell, there are no 
"optimizations" set.

I can add that the commands were executing rather slowly, so it seems to me 
unlikely that anything was happening fast enough to cause a race.

djc

On 05-Apr-19 16:36, Eli Zaretskii wrote:
>> From: DJC <djc@resiak.org>
>> Date: Fri, 5 Apr 2019 16:13:24 +0200
>>
>> In the upper window of a frame I had several hundred lines containing the
>> full paths of filenames within quotation marks -- all containing non-ASCII
>> accented European characters -- and in the lower window a Windows shell.
>>   From the shell window I used a macro to change windows, grab a file name,
>> then return to the shell window and issue
>>
>>       del {filename within quotation marks}
>>
>> After confirming that this was working as desired, I issued a command to
>> repeat the macro indefinitely.  As lines scrolled in the shell window I
>> remarked some errors in the display there: certain improper bits were being
>> displayed rather consistently.  When the run was finished, I grabbed a
>> screen shot of the quiescent state (attached) showing some of these.
> 
> You mean, those stray pixels after "5" in "HS2015"?  And also the
> artifacts before the backslashes in last two lines you captured?
> 
> If so, I suggest to review the settings of your display driver, and if
> there are any "optimization" options there, turn them off.
> 
> Thanks.
> 

bug#35158: 26.1; Display bugs: odd bits wrong in shell window

[Eli Zaretskii]

> Cc: 35158@debbugs.gnu.org
> From: DJC <djc@resiak.org>
> Date: Fri, 5 Apr 2019 17:16:00 +0200
> 
> Thanks for the suggestion.  But as far as I can tell, there are no 
> "optimizations" set.

Any optional features at all there?

> I can add that the commands were executing rather slowly, so it seems to me 
> unlikely that anything was happening fast enough to cause a race.

This isn't about a race, this is usually caused by buggy display
driver software/firmware.

bug#35158: 26.1; Display bugs: odd bits wrong in shell window

[Stefan Kangas]

Eli Zaretskii <eliz@gnu.org> writes:

>> Cc: 35158@debbugs.gnu.org
>> From: DJC <djc@resiak.org>
>> Date: Fri, 5 Apr 2019 17:16:00 +0200
>> 
>> Thanks for the suggestion.  But as far as I can tell, there are no 
>> "optimizations" set.
>
> Any optional features at all there?

More information was requested, but none was given within 12 months.

>> I can add that the commands were executing rather slowly, so it seems to me 
>> unlikely that anything was happening fast enough to cause a race.
>
> This isn't about a race, this is usually caused by buggy display
> driver software/firmware.

It also seems likely that this is not a bug in Emacs.

I'm therefore closing this bug.  If this is still an issue, please
reply to this email (use "Reply to all" in your email client) and we
can reopen the bug report.

Best regards,
Stefan Kangas