bug#59075: 29.0.50; Image transforms not applied to svg images

[Stephen Berman <stephen.berman@gmx.net>]

On Sun, 6 Nov 2022 19:07:17 +0300 Evgeny Zajcev <lg.zevlg@gmail.com> wrote:

> вс, 6 нояб. 2022 г. в 16:02, Stephen Berman <stephen.berman@gmx.net>:
>
>  On Sun, 06 Nov 2022 14:33:30 +0200 Eli Zaretskii <eliz@gnu.org> wrote:
>
>  >> From: Evgeny Zajcev <lg.zevlg@gmail.com>
>  >> Date: Sun, 6 Nov 2022 14:52:17 +0300
>  >> Cc: 59075@debbugs.gnu.org
>  >>
>  >>  If this is caused by upgrading to a newer librsvg, why are you certain
>  >>  that it's an Emacs bug and not a librsvg bug?
>  >>
>  >> Newer librsvg is known to have few bugs that we have already reported to the
>  >> librsvg community.
>  >> However, in this particular case I'm not sure this is caused by librsvg
>  >> side, why transforms starts to apply
>  >> after changing image type in the image spec?
>  >
>  > I don't know.  I'm not sure it's a librsvg bug, I'm just saying it
>  > could be theirs as well as ours.  We need a librsvg expert to tell.
>  > Anyone?
>
>  I'm no librsvg expert, but I don't see the OP's problem on master
>  running under GNU/Linux with librsvg 2.54.5, GTK+ 3.24.34, cairo 1.17.6.
>
> Possibly svg image with defined viewBox should be used to trigger
> this.  Could you please try original image I've used -
> http://lgarc.narod.ru/pics/github-octocat.svg
>
> Try also applying `:scale` transformer along with the `:height' as in my example

I downloaded the image and evaluated the following:

(insert-image '(image :type svg :file "~/temp/github-octocat.svg" :ascent center :height 16))

(insert-image '(image :type svg :file "~/temp/github-octocat.svg" :ascent center :height 16 :scale 1))

(insert-image '(image :type svg :file "~/temp/github-octocat.svg" :ascent center :height 16 :scale 2))

(insert-image '(image :type svg :file "~/temp/github-octocat.svg" :ascent center :height 16 :scale 0.5))

(insert-image '(image :type svg :file "~/temp/github-octocat.svg" :ascent center :scale 1))

(insert-image '(image :type svg :file "~/temp/github-octocat.svg" :ascent center :scale 2))

(insert-image '(image :type svg :file "~/temp/github-octocat.svg" :ascent center :scale 0.5))

and in each case the image was displayed correctly sized according to
the image specs.

Steve Berman