bug#64908: 29.1; svg parse failure

[David Ponce]

On 05/08/2023 17:14, Alan Third wrote:
> On Sat, Aug 05, 2023 at 02:32:07PM +0200, David Ponce wrote:
> > On 05/08/2023 11:58, Alan Third wrote:
> > I did test your V2 patch, and it seems to work well.
> > I tend to agree with your reasoning, even if I am not enough a
> > librsvg expert to fully understand all the details.
>
> Thanks!
>
> > One case however is not working, when the svg image just specify
> > percentage for width and height without a viewbox, like this:
> >
> > '(image :type svg :data
> >       "<svg xmlns=\"http://www.w3.org/2000/svg\"; width=\"100%\" height=\"100%\">
> >    <defs id=\"defs3051\">
> >      <style type=\"text/css\" id=\"current-color-scheme\">
> >        .ColorScheme-Text {
> >          color:#232629;
> >        }
> >        </style>
> >    </defs>
> >   <path
> >      style=\"fill:currentColor;fill-opacity:1;stroke:none\"
> >      d=\"m7.707031 3l-.707031.707031 6.125 6.125 1.167969 1.167969-1.167969 
> > 1.167969-6.125 6.125.707031.707031 6.125-6.125 1.875-1.875-1.875-1.875-6.125-6.125\"
> >      class=\"ColorScheme-Text\"
> >      />
> > </svg>"
> >       :scale 1)
> >
> > I can display a such image in firefox, gwenview, or inkscape, but not in Emacs.
> > I guess it works in applications that provide a default viewbox when not 
> > defined.
> > And it is failing in Emacs because no default viewbox is provided.
>
> Very strange, it works here. rsvg_handle_get_geometry_for_layer should
> handle this fine. I wonder if something subtle has changed with
> 2.56... I can't fine anything in the documentation to say this has
> changed...
>
> We can always provide an absolute fallback of 100x100 or something. I
> think that's what we used to do. But it would be good to know if
> something is actually broken here. Are you able to check the return
> value of rsvg_handle_get_geometry_for_layer and see if it's throwing
> up an error?

Using this image spec:

'(image :type svg :data
     "<svg xmlns=\"http://www.w3.org/2000/svg\"; width=\"100%\" height=\"100%\">
  <defs id=\"defs3051\">
    <style type=\"text/css\" id=\"current-color-scheme\">
      .ColorScheme-Text {
        color:#232629;
      }
      </style>
  </defs>
 <path
    style=\"fill:currentColor;fill-opacity:1;stroke:none\"
    d=\"m7.707031 3l-.707031.707031 6.125 6.125 1.167969 1.167969-1.167969 
1.167969-6.125 6.125.707031.707031 6.125-6.125 1.875-1.875-1.875-1.875-6.125-6.125\"
    class=\"ColorScheme-Text\"
    />
</svg>"
     :scale 1 :width 22 :height 22)

rsvg_handle_get_geometry_for_layer returns 1, and insert-image displays
a black square of 22x22 pixels.