bug#61974: 29.0.60; customize checkbox and radio widgets don't render on macOS

[David Caldwell <david@porkrind.org>]

On 3/5/23 2:42 AM, Po Lu wrote:
> Eli Zaretskii <eliz@gnu.org> writes:
> 
>> My impression was that such a conclusion would be too drastic, as many
>> SVG images can undoubtedly be displayed.
> 
> I don't know... Emacs code has never been prepared for native SVG
> display before, as this is a new feature in Mac OS.

The splash screen renders nicely, at least.

I poked around a little more and found that the OS seems to be just 
ignoring the "em" in "height=1em" and setting its height to 1. I thought 
maybe if I forced the image height to something reasonable that it would 
render but it doesn't change anything--still just a blank image.

One thought I had was that maybe Emacs is approaching this 
backward—currently the widget code says "please draw the checkbox here" 
and the checkbox svg says "I should be one lineheight high please". What 
if it instead the widget code said "Please draw the checkbox image here 
with the height of my line" and the image said nothing.

The complication there is that you probably don't want to scale 
non-vector images.

But that also is kind of a drastic change.