bug#36315: 27.0.50; SVG transparency handling is inaccurate

[Eli Zaretskii]

> Date: Mon, 01 Jul 2019 12:46:55 +0900
> From: YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
> Cc: pipcet@gmail.com,
>       36315@debbugs.gnu.org
> 
> > It just looks like we are using libcairo and not librsvg.
> >
> > 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.

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.

So on balance, I prefer the original fix, which was much simpler.
Assuming it fixed the problem, of course (I didn't try).