bug#60588: 30.0.50; Can't display PNG

bug#60588: 30.0.50; Can't display PNG

[Jean Louis]

I can't display this PNG:
https://gnu.support/files/tmp/2023-01-06/CMU_Fonts.png



In GNU Emacs 30.0.50 (build 2, x86_64-pc-linux-gnu, X toolkit, cairo
 version 1.17.6, Xaw3d scroll bars) of 2023-01-06 built on
 protected.rcdrun.com
Repository revision: 15fc7b3cde92e420f48dfe188251e6af4d832af5
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101004
System Description: Parabola GNU/Linux-libre

Configured using:
 'configure --with-x-toolkit=lucid --with-mailutils'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSYSTEMD LIBXML2 M17N_FLT MODULES NOTIFY INOTIFY
PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS
TREE_SITTER WEBP X11 XAW3D XDBE XIM XINPUT2 XPM LUCID ZLIB

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

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-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
  blink-cursor-mode: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
epg-config gnus-util text-property-search time-date subr-x mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
cl-loaddefs cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils rmc iso-transl tooltip cconv eldoc paren electric
uniquify ediff-hook vc-hooks lisp-float-type elisp-mode 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 lisp-mode
prog-mode register page tab-bar menu-bar rfn-eshadow isearch easymenu
timer select scroll-bar mouse jit-lock font-lock syntax font-core
term/tty-colors frame minibuffer nadvice seq simple cl-generic
indonesian philippine 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 emoji-zwj charscript charprop case-table epa-hook
jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button loaddefs
theme-loaddefs faces cus-face macroexp files window text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget keymap
hashtable-print-readable backquote threads dbusbind inotify lcms2
dynamic-setting system-font-setting font-render-setting cairo x-toolkit
xinput2 x multi-tty make-network-process emacs)

Memory information:
((conses 16 38914 6301)
 (symbols 48 5213 2)
 (strings 32 14149 1661)
 (string-bytes 1 397299)
 (vectors 16 10441)
 (vector-slots 8 158937 9580)
 (floats 8 40 19)
 (intervals 56 256 0)
 (buffers 984 11))

-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

In support of Richard M. Stallman
https://stallmansupport.org/

bug#60588: 30.0.50; Can't display PNG

[Eli Zaretskii]

> From: Jean Louis <bugs@gnu.support>
> Date: Fri, 06 Jan 2023 02:37:19 +0300
> 
> 
> I can't display this PNG:
> https://gnu.support/files/tmp/2023-01-06/CMU_Fonts.png

I can display it with no trouble at all.

Did you update your libpng lately?  In that case, perhaps that is the
reason for this bug (and also for the one with displaying PDF?) -- it
could be that Emacs has some problems with this new version of libpng.

Did you rebuild Emacs after updating libpng (if indeed you did update
it)?  If not, please be sure to download and install the dev package
(header files and dependency libraries, if any) of the libpng shared
library you now have, and rebuild Emacs after installing them.

bug#60588: 30.0.50; Can't display PNG

[Juri Linkov]

> I can't display this PNG:
> https://gnu.support/files/tmp/2023-01-06/CMU_Fonts.png

You can customize 'max-image-size'.

PS: Maybe we should emit a warning when an image can't be
displayed due to this limitation.

bug#60588: 30.0.50; Can't display PNG

[Eli Zaretskii]

> Cc: 60588@debbugs.gnu.org
> From: Juri Linkov <juri@linkov.net>
> Date: Fri, 06 Jan 2023 09:31:30 +0200
> 
> > I can't display this PNG:
> > https://gnu.support/files/tmp/2023-01-06/CMU_Fonts.png
> 
> You can customize 'max-image-size'.
> 
> PS: Maybe we should emit a warning when an image can't be
> displayed due to this limitation.

Good idea.  But do we know that the failure is due to memory?

bug#60588: 30.0.50; Can't display PNG

[Jean Louis]

* Eli Zaretskii <eliz@gnu.org> [2023-01-06 10:02]:
> > From: Jean Louis <bugs@gnu.support>
> > Date: Fri, 06 Jan 2023 02:37:19 +0300
> > 
> > 
> > I can't display this PNG:
> > https://gnu.support/files/tmp/2023-01-06/CMU_Fonts.png
> 
> I can display it with no trouble at all.
> 
> Did you update your libpng lately?  In that case, perhaps that is the
> reason for this bug (and also for the one with displaying PDF?) -- it
> could be that Emacs has some problems with this new version of libpng.
> 
> Did you rebuild Emacs after updating libpng (if indeed you did update
> it)?  If not, please be sure to download and install the dev package
> (header files and dependency libraries, if any) of the libpng shared
> library you now have, and rebuild Emacs after installing them.

Yes, that happened after building Emacs. In the meantime I did not
change system libraries, and I remember watching that PNG before this
latest build.

--
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

In support of Richard M. Stallman
https://stallmansupport.org/

bug#60588: 30.0.50; Can't display PNG

[Jean Louis]

* Juri Linkov <juri@linkov.net> [2023-01-06 10:32]:
> > I can't display this PNG:
> > https://gnu.support/files/tmp/2023-01-06/CMU_Fonts.png
> 
> You can customize 'max-image-size'.
> 
> PS: Maybe we should emit a warning when an image can't be
> displayed due to this limitation.

When I set `max-image-size' to nil, then I can see that image.

As user I am not aware of that variable. If Emacs can't show the
image, then it should tell me why, for example, that it can't show
images because of `max-image-size' being set too little, and it should
also tell me to what should I set it to display that image.

Default was 10.0 which did not work.

-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

In support of Richard M. Stallman
https://stallmansupport.org/

bug#60588: 30.0.50; Can't display PNG

[Eli Zaretskii]

> Cc: 60588@debbugs.gnu.org
> Date: Fri, 6 Jan 2023 16:09:19 +0300
> From: Jean Louis <bugs@gnu.support>
> 
> Default was 10.0 which did not work.

That value didn't change since Emacs 24.  So if a build from few days
ago did work with that PNG file, then something other than Emacs has
changed on your system.

bug#60588: 30.0.50; Can't display PNG

[Andreas Schwab]

On Jan 06 2023, Eli Zaretskii wrote:

>> Cc: 60588@debbugs.gnu.org
>> Date: Fri, 6 Jan 2023 16:09:19 +0300
>> From: Jean Louis <bugs@gnu.support>
>> 
>> Default was 10.0 which did not work.
>
> That value didn't change since Emacs 24.  So if a build from few days
> ago did work with that PNG file, then something other than Emacs has
> changed on your system.

Since the default is a ratio, it also depends on the frame layout.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

bug#60588: 30.0.50; Can't display PNG

[Eli Zaretskii]

> From: Andreas Schwab <schwab@linux-m68k.org>
> Cc: Jean Louis <bugs@gnu.support>,  60588@debbugs.gnu.org,  juri@linkov.net
> Date: Fri, 06 Jan 2023 15:58:26 +0100
> 
> On Jan 06 2023, Eli Zaretskii wrote:
> 
> >> Cc: 60588@debbugs.gnu.org
> >> Date: Fri, 6 Jan 2023 16:09:19 +0300
> >> From: Jean Louis <bugs@gnu.support>
> >> 
> >> Default was 10.0 which did not work.
> >
> > That value didn't change since Emacs 24.  So if a build from few days
> > ago did work with that PNG file, then something other than Emacs has
> > changed on your system.
> 
> Since the default is a ratio, it also depends on the frame layout.

Yes, if that has changed in Jean's configuration lately, it could also
be the reason.