bug#19373: 24.4; SVG images rendered via librsvg fail at displaying non-inline bitmap images

[Vasilij Schneidermann <hurrus.durrus@gmail.com>]

I've recently tested Emacs' support for displaying SVG images that
contain bitmap images.  The test files used were
<http://dev.w3.org/SVG/profiles/1.1F2/test/svg/struct-image-04-t.svg>
and
<http://dev.w3.org/SVG/profiles/1.1F2/test/svg/struct-image-02-b.svg>.
The imagemagick backend displays both pictures flawlessly, but renders
transparency as white background which makes it unsuitable for my
purposes.  The librsvg backend appears to render transparency correctly,
however in the first example with inline bitmaps the first image isn't
displayed at all (which can be easily fixed by replacing "jpg" with
"jpeg" in its sources); in the second example the non-inline bitmap
isn't displayed either.  I've tried tracking down the reason for this
behavior and the only pointer I could find was that librsvg is using
the cairo library to embed the bitmap image.  Is there any obvious fix I
can apply to remedy this issue?



In GNU Emacs 24.4.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.14.3)
 of 2014-10-21 on bitzer.hoetzel.info
Windowing system distributor `The X.Org Foundation', version 11.0.11602000
System Description:	Arch Linux

Configured using:
 `configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --with-x-toolkit=gtk3 --with-xft
 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong
 --param=ssp-buffer-size=4' CPPFLAGS=-D_FORTIFY_SOURCE=2
 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro'

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Fundamental

Minor modes in effect:
  tooltip-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
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
M-x r e p o r t - e m <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
/usr/share/emacs/site-lisp/SuperCollider/tree-widget hides /usr/share/emacs/24.4/lisp/tree-widget

Features:
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rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045
ietf-drums mm-util help-fns mail-prsvr mail-utils time-date tooltip
electric uniquify ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd
tool-bar dnd fontset image regexp-opt fringe tabulated-list newcomment
lisp-mode prog-mode register page menu-bar rfn-eshadow timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core frame cham
georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese hebrew greek romanian slovak czech european ethiopic
indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple
abbrev minibuffer 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 make-network-process
dbusbind gfilenotify dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)

Memory information:
((conses 16 73812 6500)
 (symbols 48 17579 0)
 (miscs 40 77 163)
 (strings 32 9145 4185)
 (string-bytes 1 252188)
 (vectors 16 8986)
 (vector-slots 8 384469 17487)
 (floats 8 63 185)
 (intervals 56 216 4)
 (buffers 960 12)
 (heap 1024 45321 956))