Interactions: Don't (always) accept empty names

[obenland]

Proposed changes:

• Looks for an actual name or preferredUsername, rather than just the key being present.
• Checks require_name_email option before rejecting a likes, comments, or reposts.
• Falls back to "Anonymous" of no-name comments are allowed.
• Adds tests.

Other information:

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

Testing instructions:

• Create an external user without a name, like https://browser.pub/https://pixelfed.social/pfefferle
• React to a test post.
• Make sure that the preferredUsername shows up in the Reactions block's list of users.

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

Likes, comments, and reposts from the Fediverse now require either a name or preferredUsername to be set when the Discussion option require_name_email is set to true. It falls back to "Anonymous", if not.

[Copilot]

Pull Request Overview

Enhance comment author handling by requiring a non-empty name or preferredUsername (when configured), falling back to "Anonymous" otherwise, and adding tests for these behaviors.

• Enforce non-empty name or preferredUsername, and reject anonymous comments if require_name_email is enabled
• Use "Anonymous" fallback for comments when names are allowed but missing
• Add unit tests covering all author name scenarios

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
tests/includes/collection/class-test-interactions.php	New tests for activity_to_comment author logic, including rejection and fallback
includes/collection/class-interactions.php	Updated activity_to_comment to validate non-empty actor names and handle anonymous fallback

Comments suppressed due to low confidence (1)

tests/includes/collection/class-test-interactions.php:592

• The docblock declares $response as bool, but the callback actually returns an array of metadata. Update the @param type to array|string[].

@param bool   $response The value to return instead of the remote metadata.

[Copilot]

Restore sanitization on comment_author (e.g., wrap in esc_attr()) to prevent unsanitized user input from being stored or output.

Suggested change

	'comment_author' => $comment_author ?? __( 'Anonymous', 'activitypub' ),
	'comment_author' => \esc_attr( $comment_author ?? __( 'Anonymous', 'activitypub' ) ),