gradients are lost in compression

[ofrias]

Describe the bug
When compressing this file with svgo default settings the gradients are lost.

To Reproduce

1. Download https://upload.wikimedia.org/wikipedia/commons/1/19/Logo_TVE-1.svg
2. Run svgo Logo_TVE-1.svg

Expected behavior
Gradients should be preserved.

Desktop (please complete the following information):

• SVGO Version 3.0.2
• OS: Ubuntu 22.04.1 LTS

Additional context
If I compress the file first with scour and then with svgo everything works OK.

[SethFalco]

MRE of the issue, though it's actually the blur that was lost, not the gradient!

I haven't checked the code yet, but the problem is in the cleanupIds plugin. For some reason, it decides to remove the id="c" attribute from the filter, so nodes referencing it lose the blur.

original.svg

<svg xmlns="http://www.w3.org/2000/svg" width="1950.1315" height="1740.1298">
  <defs>
    <linearGradient id="a">
      <stop stop-color="#f00" offset="0"/>
    </linearGradient>
    <filter id="c" style="color-interpolation-filters:sRGB" x="-0.2760295" width="1.5520591" y="-0.33142158" height="1.6628431">
      <feGaussianBlur stdDeviation="331.22039"/>
    </filter>
  </defs>
  <g transform="matrix(5.8862959,0,0,5.8862959,-228.3949,1414.6785)">
    <path d="m 6416.0915,21026.021 c 496.2734,-430.162 1156.7926,-524.889 1495.2326,-581.643 1461.5227,-245.087 1539.467,2033.775 96.1224,2234.099 -524.6707,72.82 -1265.3758,450.675 -1679.5812,-402.754 -315.0174,-535.208 -91.5956,-1058.609 88.2262,-1249.702 z" style="opacity:1;fill:url(#a);fill-opacity:1;stroke:none;stroke-width:16.60000038;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1;filter:url(#c)" transform="matrix(0.07412091,0,0,0.07412091,-359.59058,-1695.4044)"/>
  </g>
</svg>

svgo.config.js

module.exports = {
  plugins: [
    "cleanupIds",
  ],
};

optimized.svg (prettified)

<svg xmlns="http://www.w3.org/2000/svg" width="1950.1315" height="1740.1298">
  <defs>
    <linearGradient id="a">
      <stop stop-color="#f00" offset="0"/>
    </linearGradient>
    <filter style="color-interpolation-filters:sRGB" x="-0.2760295" width="1.5520591" y="-0.33142158" height="1.6628431">
      <feGaussianBlur stdDeviation="331.22039"/>
    </filter>
  </defs>
  <g transform="matrix(5.8862959,0,0,5.8862959,-228.3949,1414.6785)">
    <path d="m 6416.0915,21026.021 c 496.2734,-430.162 1156.7926,-524.889 1495.2326,-581.643 1461.5227,-245.087 1539.467,2033.775 96.1224,2234.099 -524.6707,72.82 -1265.3758,450.675 -1679.5812,-402.754 -315.0174,-535.208 -91.5956,-1058.609 88.2262,-1249.702 z" style="opacity:1;fill:url(#a);fill-opacity:1;stroke:none;stroke-width:16.60000038;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1;filter:url(#c)" transform="matrix(0.07412091,0,0,0.07412091,-359.59058,-1695.4044)"/>
  </g>
</svg>