bug#36315: 27.0.50; SVG transparency handling is inaccurate

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 02 Jul 2019 18:46:28 +0900
> From: YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
> Cc: 	pipcet@gmail.com,
> 	36315@debbugs.gnu.org
> 
> > > > Again, it isn't something entirely rational, it just sounds weird to
> > > > me.  Imagine that users libxml2 would need to call libiconv to decode
> > > > UTF-8 encoded text in an XML file, for example.  Doesn't look right.
> > > 
> > > The situation for libcairo and librsvg should be familiar to us: we
> > > are directly using Emacs core functionality even when working with
> > > several major or minor modes.
> > 
> > Not sure what this alludes to.
> 
> The correspondence is:
> 
>   libcairo - Emacs core functionality
>   librsvg  - Major/minor mode (e.g., Org mode)
> 
> Major/minor modes are not designed to be used in their own right, but
> with (the direct use of) Emacs core functionality.  Would Org mode
> users complain that it looks like they are using Emacs and not Org
> mode?
> 
> Even the current SVG support code does something like this:
> 
>   /* Create a new RsvgHandle object.  */
>   rsvg_handle = rsvg_handle_new ();
> 
>   /* Do some tasks with rsvg_handle.  */
> 
>   /* Free the RsvgHandle object.  */
>   g_object_unref (rsvg_handle);
> 
> Do you reject this code because it looks like we are using gobject and
> not librsvg?
> 
> > One thing that bothers me with using sub-libraries is that we now need
> > another entry in dynamic-library-alist, which means complications if
> > Cairo ever changes its ABI and we will need to use libcairo-N.dll
> > where N > 2.
> 
> The patch also removes the entry for gdk-pixbuf, so the situation is
> not getting worse.
> 
> FWIW, if we want to fix bug#35548 (use of rsvg_handle_write and
> rsvg_handle_close that are being deprecated), then we will need to add
> an entry for gio.

We clearly disagree, and I already said I didn't think this is worth
an argument.  Feel free to do whatever you see fit.