The toggle existed in the UI with no implementation behind it, so
uploads were rejected regardless of the setting. New SvgUploads class:
- Allowlists the SVG mime type and fixes WP's real-mime sniff, which
otherwise nulls out the file type for SVGs specifically even after
the mime allowlist is updated.
- Populates width/height metadata (parsed from the SVG's own
viewBox/width/height) — without this, wp_get_missing_image_subsizes()
throws undefined-array-key warnings that can corrupt the upload
response's JSON on environments with warnings displayed inline.
- Basic sanitization on upload (strips <script> tags, inline event
handlers, javascript: URIs).
Verified live via the REST media endpoint: clean upload with correct
dimensions, and a malicious test SVG had its script/handlers stripped
while staying valid markup.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
