Plugins reusePaths and removeXMLNS conflict as of version 2.8.0

[remcohaszing]

Describe the bug

As of version 2.8.0, combining both removeXMLNS and reusePaths yields an error.

To Reproduce

Steps to reproduce the behavior:

Given the following script:

const { optimize } = require('svgo');

const options = {
  js2svg: {
    indent: 2,
    pretty: true,
  },
  multipass: true,
  plugins: [
    { name: 'reusePaths', active: true },
    { name: 'removeXMLNS', active: true },
  ],
}

const svg = `
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 0 0">
  <defs>
    <path d=""></path>
    <path d=""></path>
  </defs>
</svg>
`

const result = optimize(svg, options);

console.dir(result);

1. Install svgo 2.7.0
2. Run the script
3. Notice a result is logged
4. Install svgo 2.8.0
5. Run the script
6. Notice an error is logged

The following will make the error go away:

• Set multipass: false
• Disable the reusePaths plugin
• Disable the removeXMLNS plugin

Expected behavior

Used namespaces aren’t removed by removeXMLNS, so the plugins can work together.

Screenshots

N/A

Desktop (please complete the following information):

• SVGO Version: 2.8.0
• NodeJs Version 16.13.0
• OS: Pop!_OS 21.04

Additional context

The error was introduced in version 2.8.0.

[TrySound]

Yeah, parser indeed doesn't understand unbound namespace. This was unexpecteed. But anyway, at the moment only convertTransform may produce different result with multipass. And we gonna make it more deterministic. So I recommend to disable multipass mode. It will be removed in v3.

[cyberalien]

It will be removed in v3.

Still bugged in 3.0.2

[SethFalco]

Hey, and thanks for reporting the issue!

This has been resolved and will be released in SVGO v3.0.4.

• removeXMLNS will no longer remove the XLink namespace at all.
• A new plugin, removeXlink can be used to migrate from the XLink namespace to the SVG 2 equivalent when only SVG 2 or inline HTML compatibility is required. (disabled by default)