DOMException: Failed to execute 'setAttributeNS' on 'Element' on `<svg xmlns:xlink>`

[nolanlawson]

Description

<svg>s with the xmlns:xlink attribute cause a runtime error that only occurs with dynamic VNodes (not static ones).

Steps to Reproduce

<template>
    <svg
        data-dynamic={foo}
        xmlns:xlink="http://www.w3.org/1999/xlink"
    ></svg>
</template>

Result

Uncaught DOMException: Failed to execute 'setAttributeNS' on 'Element': 'http://www.w3.org/1999/xlink' is an invalid namespace for attributes.

The error is thrown from LWC here:

lwc/packages/@lwc/engine-dom/src/renderer/index.ts

Line 84 in 8111f1f

: element.setAttributeNS(namespace, name, value);

...called from here:

lwc/packages/@lwc/engine-core/src/framework/modules/attrs.ts

Lines 55 to 57 in 8111f1f

	} else if (StringCharCodeAt.call(key, 5) === ColonCharCode) {
	// Assume xlink namespace
	setAttribute(elm, key, cur as string, XLINK_NAMESPACE);

If you remove data-dynamic={foo} above, it will render correctly.

Repro

[git2gus]

This issue has been linked to a new work item: W-14246830

[nolanlawson]

This is apparently not a regression; it repros in 2.41.4 (244) as well.

[nolanlawson]

Error is thrown in Chrome, Firefox, and Safari.