bug#63344: 29.0.90; (shr-zoom-image) doesn't zoom to buffer size

bug#63344: 29.0.90; (shr-zoom-image) doesn't zoom to buffer size

[Pankaj Jangid]

(shr-zoom-image) - The description says it cycles between the default
size, the original size, and full-buffer size. But it never zooms to the
full-buffer size.

Can I share attachment here? I have a 621kB screencast.


In GNU Emacs 29.0.90 (build 1, x86_64-pc-linux-gnu, GTK+ Version
 3.24.37, cairo version 1.16.0) of 2023-05-07 built on anant
Repository revision: e205f68717e960a929e5657e8351ba6ef0e5f480
Repository branch: emacs-29
System Description: Debian GNU/Linux 12 (bookworm)

Configured using:
 'configure --prefix=/home/pankaj/.local --with-pgtk --with-tree-sitter'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 MODULES NOTIFY INOTIFY
PDUMPER PGTK PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER WEBP XIM GTK3 ZLIB

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

Major mode: eww

Minor modes in effect:
  override-global-mode: t
  direnv-mode: t
  global-git-commit-mode: t
  magit-auto-revert-mode: t
  shell-dirtrack-mode: t
  server-mode: t
  editorconfig-mode: t
  which-key-mode: t
  global-hl-line-mode: t
  savehist-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  tab-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
  buffer-read-only: t
  column-number-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:
/home/pankaj/.emacs.d/elpa/transient-20230315.1520/transient hides /home/pankaj/.local/share/emacs/29.0.90/lisp/transient

Features:
(shadow sort bbdb-message mail-extr emacsbug cursor-sensor utf-7 nndraft
nnmh nnfolder nnml bbdb-gnus bbdb-mua bbdb-com epa-file gnus-agent
gnus-srvr gnus-score score-mode nnvirtual gnus-msg nntp gnus-cache .gnus
misearch multi-isearch shortdoc apropos help-fns radix-tree textsec
uni-scripts idna-mapping ucs-normalize uni-confusable textsec-check
network-stream url-cache diary-lib diary-loaddefs sh-script smie
executable oc-basic ol-eww eww url-queue mm-url ol-rmail ol-mhe ol-irc
ol-info ol-gnus nnselect gnus-art mm-uu mml2015 mm-view mml-smime smime
gnutls dig gnus-sum gnus-group gnus-undo ol-docview doc-view image-mode
exif ol-bibtex bibtex ol-bbdb ol-w3m ol-doi org-link-doi mule-util
jka-compr checkdoc lisp-mnt corfu display-fill-column-indicator
display-line-numbers init my-init kunji hdfc ob-plantuml ob-sql ob-css
ob-js ob-java ob-C ob-python python gnus-start gnus-dbus dbus gnus-cloud
nnimap nnmail mail-source utf7 nnoo parse-time gnus-spec gnus-int
gnus-range gnus-win gnus nnheader range erc-join solar cal-dst
use-package-delight erc-goodies erc iso8601 erc-backend erc-networks
erc-common erc-compat erc-loaddefs rust-ts-mode use-package-bind-key
bind-key js c-ts-common desktop frameset cus-load treesit direnv
magit-bookmark magit-submodule magit-blame magit-stash magit-reflog
magit-bisect magit-push magit-pull magit-fetch magit-clone magit-remote
magit-commit magit-sequence magit-notes magit-worktree magit-tag
magit-merge magit-branch magit-reset magit-files magit-refs magit-status
magit magit-repos magit-apply magit-wip magit-log which-func magit-diff
smerge-mode diff diff-mode easy-mmode git-commit log-edit pcvs-util
add-log magit-core magit-autorevert autorevert filenotify magit-margin
magit-transient magit-process with-editor shell server magit-mode
transient edmacro kmacro magit-git magit-base magit-section crm compat
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nxml-ns nxml-enc xmltok nxml-util ox-latex ox-icalendar org-agenda
ox-html table ox-ascii ox-publish ox org-element org-persist org-id
org-refile avl-tree debbugs soap-client mm-decode mm-bodies mm-encode
url-http url-auth mail-parse rfc2231 rfc2047 rfc2045 mm-util ietf-drums
mail-prsvr url-gw nsm rng-xsd rng-dt rng-util xsd-regexp plantuml-mode
solidity-mode solidity-common php-mode mode-local speedbar ezimage
dframe cc-mode cc-fonts cc-guess cc-menus cc-cmds cc-styles cc-align
php-face php php-project cc-engine cc-vars cc-defs gnuplot info-look
docker-compose-mode nov recentf tree-widget wid-edit org ob ob-tangle
ob-ref ob-lob ob-table ob-exp org-macro org-src ob-comint org-pcomplete
pcomplete org-list org-footnote org-faces org-entities time-date
ob-emacs-lisp ob-core ob-eval org-cycle org-table ol org-fold
org-fold-core org-keys oc org-loaddefs find-func cal-menu calendar
cal-loaddefs org-version org-compat org-macs format-spec imenu bookmark
pp shr pixel-fill kinsoku url-file puny svg xml esxml-query dom
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editorconfig-fnmatch haskell-mode haskell-cabal haskell-utils
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haskell-sort-imports haskell-lexeme rx haskell-align-imports
haskell-complete-module haskell-ghc-support noutline outline
flymake-proc flymake warnings icons dabbrev haskell-customize go-mode
find-file ffap thingatpt etags fileloop generator compile
text-property-search comint ansi-osc ansi-color gtags-mode files-x
denote xdg dired dired-loaddefs xref project ring which-key
exec-path-from-shell bbdb bbdb-site timezone delight cl-extra help-mode
use-package-ensure use-package-core modus-vivendi-theme modus-themes
hl-line savehist finder-inf solidity-mode-autoloads spinner-autoloads
prettier-autoloads nov-autoloads graphql-mode-autoloads
org-mime-autoloads nvm-autoloads f-autoloads iter2-autoloads
php-mode-autoloads denote-autoloads json-snatcher-autoloads
auctex-autoloads tex-site docker-compose-mode-autoloads
editorconfig-autoloads exec-path-from-shell-autoloads debbugs-autoloads
parseedn-autoloads bbdb-autoloads yaml-mode-autoloads parseclj-autoloads
haskell-mode-autoloads which-key-autoloads markdown-mode-autoloads
gtags-mode-autoloads corfu-autoloads go-mode-autoloads gnuplot-autoloads
plantuml-mode-autoloads 0blayout-autoloads delight-autoloads
750words-autoloads esxml-autoloads kv-autoloads queue-autoloads
direnv-autoloads sesman-autoloads groovy-mode-autoloads s-autoloads
lua-mode-autoloads magit-autoloads pcase magit-section-autoloads
git-commit-autoloads with-editor-autoloads transient-autoloads
dash-autoloads info compat-autoloads package browse-url url url-proxy
url-privacy url-expand url-methods url-history url-cookie
generate-lisp-file url-domsuf url-util mailcap url-handlers url-parse
auth-source cl-seq eieio eieio-core cl-macs password-cache json subr-x
map byte-opt gv bytecomp byte-compile url-vars cl-loaddefs cl-lib
early-init rmc iso-transl tooltip cconv eldoc paren electric uniquify
ediff-hook vc-hooks lisp-float-type elisp-mode mwheel term/pgtk-win
pgtk-win term/common-win pgtk-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 dynamic-setting system-font-setting
font-render-setting cairo gtk pgtk lcms2 multi-tty make-network-process
emacs)

Memory information:
((conses 16 1477450 47071)
 (symbols 48 53635 2)
 (strings 32 277511 12556)
 (string-bytes 1 8751194)
 (vectors 16 126151)
 (vector-slots 8 2367318 239943)
 (floats 8 1069 453)
 (intervals 56 39866 1349)
 (buffers 984 44))

bug#63344: 29.0.90; (shr-zoom-image) doesn't zoom to buffer size

[Eli Zaretskii]

> From: Pankaj Jangid <pankaj@codeisgreat.org>
> Date: Sun, 07 May 2023 12:26:49 +0530
> 
> 
> (shr-zoom-image) - The description says it cycles between the default
> size, the original size, and full-buffer size. But it never zooms to the
> full-buffer size.
> 
> Can I share attachment here? I have a 621kB screencast.

Please show a complete recipe for reproducing this issue, starting
from "emacs -Q".

There's no reason to post the screencast yet, perhaps we will be able
to reproduce this using some random image.  Unless you see this only
with a particular image and no other.

Thanks.

bug#63344: 29.0.90; (shr-zoom-image) doesn't zoom to buffer size

[Pankaj Jangid]

Eli Zaretskii <eliz@gnu.org> writes:

> Please show a complete recipe for reproducing this issue, starting
> from "emacs -Q".

Sure. The steps:

1. emacs -Q
2. M-x eww RET https://en.wikipedia.org/wiki/PackageKit RET
3. Scroll to the image showing block diagram. Bring point on the image.
4. Press "z" repeatedly to cycle zoom levels

Expected result (as per doc): It should cycle through three zoom levels.

Result: it never zooms to "full buffer size"

bug#63344: 29.0.90; (shr-zoom-image) doesn't zoom to buffer size

[Eli Zaretskii]

> From: Pankaj Jangid <pankaj@codeisgreat.org>
> Cc: 63344@debbugs.gnu.org
> Date: Sun, 07 May 2023 18:12:54 +0530
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Please show a complete recipe for reproducing this issue, starting
> > from "emacs -Q".
> 
> Sure. The steps:
> 
> 1. emacs -Q
> 2. M-x eww RET https://en.wikipedia.org/wiki/PackageKit RET
> 3. Scroll to the image showing block diagram. Bring point on the image.
> 4. Press "z" repeatedly to cycle zoom levels
> 
> Expected result (as per doc): It should cycle through three zoom levels.
> 
> Result: it never zooms to "full buffer size"

Thanks.  But what do you understand "full buffer size" to mean for the
dimension of an image?

bug#63344: 29.0.90; (shr-zoom-image) doesn't zoom to buffer size

[Pankaj Jangid]

Eli Zaretskii <eliz@gnu.org> writes:

> Thanks.  But what do you understand "full buffer size" to mean for the
> dimension of an image?

I understood that "full buffer size" implies "window width" or may be
"window height" if the aspect ration of image is that way.

If that is not the case then I have no clue what "full buffer size"
means.

bug#63344: 29.0.90; (shr-zoom-image) doesn't zoom to buffer size

[Eli Zaretskii]

> From: Pankaj Jangid <pankaj@codeisgreat.org>
> Cc: 63344@debbugs.gnu.org
> Date: Mon, 08 May 2023 10:36:46 +0530
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Thanks.  But what do you understand "full buffer size" to mean for the
> > dimension of an image?
> 
> I understood that "full buffer size" implies "window width" or may be
> "window height" if the aspect ration of image is that way.
> 
> If that is not the case then I have no clue what "full buffer size"
> means.

"Full buffer size" wrt an image is confusing in any case (an Emacs
buffer has no "dimensions"), but my reading of the code is that it is
interpreted as the window dimensions, unless the original size is
smaller than that.  Not sure if I'm right, though.

Adding Lars, who wrote that code, in the hope that he could clarify
this.

bug#63344: 29.0.90; (shr-zoom-image) doesn't zoom to buffer size

[Jim Porter]

forcemerge 71666 63344
thanks

On 5/8/2023 4:34 AM, Eli Zaretskii wrote:
> "Full buffer size" wrt an image is confusing in any case (an Emacs
> buffer has no "dimensions"), but my reading of the code is that it is
> interpreted as the window dimensions, unless the original size is
> smaller than that.  Not sure if I'm right, though.

In bug#71666, I did some archaeology on the Gnus commit history to 
figure out what this was, and found that the "full buffer size" meant 
"rescale the image to the height of the window". Over in that bug, I've 
fixed the issue described here as well as improving the wording in the 
docstrings to be more precise.