bug#54688: 29.0.50; Sliced image in margin looks bad

[dalanicolai]

Passing 'left-margin' for the AREA parameter in `insert-sliced-image`
results in bad looking image. To reproduce from `emacs -q` evaluate the
following code example:

(with-current-buffer (get-buffer-create "test")
  (setq left-margin-width 5)
  (insert-sliced-image (svg-image (let* ((ph (line-pixel-height))
                                         (size (* 2 ph))
                                         (svg (svg-create size size)))
                                    (svg-circle svg ph ph ph :fill "red")
                                    svg))
                       nil
                       'left-margin
                       2)
  (switch-to-buffer (current-buffer)))

when instead of 'left-margin', nil is passed as value (i.e. the text is
inserted in the text area), then everything looks fine.

In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.31, cairo version 1.17.4)
 of 2022-01-29 built on fedora
Repository revision: 96533c18b7f9d75dce9e6bb534a16ed4ccf44ad1
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12014000
System Description: Fedora Linux 35 (Workstation Edition)

Configured using:
 'configure --with-modules --with-cairo --with-native-compilation
 --with-json'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG JSON
LIBSELINUX LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG RSVG
SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS X11 XDBE XIM XPM
GTK3 ZLIB

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

Major mode: Lisp Interaction

Minor modes in effect:
  marginalia-mode: t
  savehist-mode: t
  vertico-mode: t
  global-evil-surround-mode: t
  evil-surround-mode: t
  recentf-mode: t
  shell-dirtrack-mode: t
  evil-mode: t
  evil-local-mode: t
  windmove-mode: t
  global-undo-tree-mode: t
  undo-tree-mode: t
  override-global-mode: t
  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
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message yank-media rmc dired
dired-loaddefs rfc822 mml mml-sec epa epg rfc6068 epg-config gnus-util
time-date mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mule-util cursor-sensor format-all language-id inheritenv
gitter derived pcase let-alist posframe transient format-spec request
autorevert filenotify mail-utils notifications dbus avy
shr-tag-pre-highlight language-detection shr text-property-search
pixel-fill kinsoku puny svg xml ewoc marginalia savehist orderless
vertico evil-surround evil-nerd-commenter evil-nerd-commenter-operator
evil-nerd-commenter-sdk sgml-mode facemenu dom which-key bind-map
recentf tree-widget wid-edit evil evil-keybindings evil-integration
evil-maps evil-commands reveal flyspell ispell evil-jumps
evil-command-window evil-types evil-search evil-ex shell pcomplete
comint ansi-color evil-macros evil-repeat evil-states evil-core comp
comp-cstr warnings rx advice evil-common windmove thingatpt rect
evil-digraphs evil-vars ring edmacro kmacro undo-tree diff cl-extra
help-mode use-package use-package-ensure use-package-delight
use-package-diminish use-package-bind-key bind-key easy-mmode
use-package-core finder-inf info package browse-url url url-proxy
url-privacy url-expand url-methods url-history url-cookie url-domsuf
url-util mailcap url-handlers url-parse auth-source cl-seq eieio
eieio-core cl-macs eieio-loaddefs password-cache json map url-vars seq
gv subr-x byte-opt bytecomp byte-compile cconv cl-loaddefs cl-lib
chemacs iso-transl tooltip 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 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 emoji-zwj charscript charprop case-table epa-hook
jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice button
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
move-toolbar gtk x-toolkit x multi-tty make-network-process
native-compile emacs)

Memory information:
((conses 16 350688 17872)
 (symbols 48 22237 1)
 (strings 32 115274 5006)
 (string-bytes 1 3507701)
 (vectors 16 225348)
 (vector-slots 8 1419197 79043)
 (floats 8 90951 50)
 (intervals 56 651 0)
 (buffers 992 13))