Avatars: Update filters, fallbacks, and API use

[obenland]

I was looking for a way to photonize avatar urls on WP.com for the Reactions block and realized that there's no way to filter the avatar url. This PR makes it possible to filter the URL and updates all other direct calls to comment meta to get the avatar url.

Proposed changes:

• Uses get_avatar_url() instead of getting avatar_url comment meta directly.
• Adds filter docs for get_avatar_comment_types filter.
• Adds fallback for empty comment types instead of failing them.
• Removes get_avatar_data filter call to avoid double-filtering the value.
• Adds get_avatar_url filter to avatar_url comment meta.

Other information:

• Have you written new tests for your changes, if applicable?

Testing instructions:

• Find a post with Reactions and make sure avatars are the same before and after this change.
• Edit that post and insert a reactions block if it doesn't already have one. Make sure avatars look right.

Changelog entry

• Automatically create a changelog entry from the details below.

Changelog Entry Details

Significance

• Patch
• Minor
• Major

Type

• Added - for new features
• Changed - for changes in existing functionality
• Deprecated - for soon-to-be removed features
• Removed - for now removed features
• Fixed - for any bug fixes
• Security - in case of vulnerabilities

Message

Unified retrieval of comment avatars and re-used core filters to give access to third-part plugins.

[Copilot]

Pull Request Overview

This PR centralizes avatar URL retrieval by switching from direct comment meta access to the core get_avatar_url() function, and adds filter and fallback support for comment types.

• Replaced all direct calls to get_comment_meta(..., 'avatar_url', true) with get_avatar_url().
• Added and documented a get_avatar_comment_types filter, with a fallback for undefined comment types.
• Removed a redundant get_avatar_data filter call and applied the get_avatar_url filter in ActivityPub integration.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/reactions/render.php	Swap get_comment_meta for get_avatar_url
includes/rest/class-post-controller.php	Use get_avatar_url instead of direct comment meta access
includes/class-activitypub.php	Introduce get_avatar_comment_types filter, fallback logic, remove double-filtering, and apply get_avatar_url
build/reactions/render.php	Mirror the render.php update in the built artifact

Comments suppressed due to low confidence (2)

includes/class-activitypub.php:338

• The docblock for get_avatar_comment_types filter is missing a @return array annotation to describe the expected return value.

* @param array $allowed_comment_types Array of allowed comment types.

includes/class-activitypub.php:341

• Introduce or update unit tests to cover the new fallback behavior when comment_type is empty or not in the allowed list, ensuring no unintended avatar URLs are returned.

if ( ! \in_array( $id_or_email->comment_type ?: 'comment', $allowed_comment_types, true ) ) { // phpcs:ignore Universal.Operators.DisallowShortTernary

[obenland]

@pfefferle I think I'm missing historic context, hoping for you to be able to fill in my blanks.

My understanding is that setting the url will short-circuit get_avatar_data() for all cases where the comment type is not part of the $allowed_comment_types array, so things like pings and trackbacks and such. Is that on purpose?

[pfefferle]

exactly this

[obenland]

Could you help me unpack that a bit more? What's the purpose for disabling avatars for all other comment types?

[pfefferle]

they simply do not have avatars!?

[pfefferle]

but I have no strong feelings about that... happy to remove it!

[obenland]

For context: Previously this conditional failed for an empty comment_type, which used to be the default for comments before WP 5.5. We no longer support WP versions that old, but I wonder if we should still just fallback to comment, instead of bailing and disabling avatars.

[pfefferle]

happy to remove the fallback!