transform matrix3d has a disco nightclub behavior

[Karl Dubost]

<div class="container">
  <div id="test">200x200</div></div>

with 

body {  
  margin:0;
  padding:0;
  }

.container {
  margin: 10px;
  outline: 4px solid pink;
  width: 200px;
  height: 200px;}

#test {
  width: 200px;
  background-color: gold;
  height: 200px;}

/*transforms*/

#test {
  transform:
     matrix3d(1, 1, 1, 1,
             1, 1, 1, 1,
             1, 1, 1, 1,
             1, 1, 1, 1);
     
}


1. Go to https://codepen.io/webcompat/pen/Povbwwa
2. Resize the viewport of the test, and it flashes gold in all directions.

[Karl Dubost]

Created attachment 471519 [details]
recording of the effect

The disco part

[Radar WebKit Bug Importer]

<rdar://problem/128783333>

[Karl Dubost]

This was tested with STP Release 191 (Safari 17.4, WebKit 619.1.6.3)

on Firefox and Chrome, nothing appears at all.