DOMParser: clarify XML error handling

[danburzo]

Summary

Updated the DOMParser.parseFromString and Parsing and serializing XML pages with better error handling.

Motivation

According to the HTML standard, when encountering non-conforming input, the XML parser produces a <parsererror> node as the root of the resulting XMLDocument. However, in Safari and Chrome, this node is not always the root.

Supporting details

Related issues

Fixes #9380.

Metadata

• Adds a new document
• Rewrites (or significantly expands) a document
• Fixes a typo, bug, or other error

[github-actions]

Preview URLs

• https://pr9383.content.dev.mdn.mozit.cloud/en-US/docs/Web/API/DOMParser/parseFromString
• https://pr9383.content.dev.mdn.mozit.cloud/en-US/docs/Web/Guide/Parsing_and_serializing_XML

Flaws

Note! 1 document with no flaws that don't need to be listed. 🎉

URL: /en-US/docs/Web/API/DOMParser/parseFromString
Title: DOMParser.parseFromString()
on GitHub
Flaw count: 1

• macros:
  • /en-US/docs/Glossary/xhtml+xml does not exist

External URLs

URL: /en-US/docs/Web/Guide/Parsing_and_serializing_XML
Title: Parsing and serializing XML
on GitHub

No new external URLs

---

URL: /en-US/docs/Web/API/DOMParser/parseFromString
Title: DOMParser.parseFromString()
on GitHub

No new external URLs

[danburzo]

I would also take this chance to clarify that the DOMParser doesn't do any SVG-specific magic when using image/svg+xml MIME type, can I do it in this PR or shall I submit a separate one?

[wbamberg]

Thanks for this PR!

I would also take this chance to clarify that the DOMParser doesn't do any SVG-specific magic when using image/svg+xml MIME type, can I do it in this PR or shall I submit a separate one?

...and thanks for asking about this! I'd prefer a separate PR. I'll review this one today, so you're not left hanging :).

[wbamberg]

👍 thanks @danburzo , this looks great to me!

[danburzo]

Cool, thanks!