Fix activitypub_max_image_attachments check

[pfefferle]

The code currently uses the Ternary Operator (?:) to check if the activitypub_max_image_attachments meta is set and to fallback to the default ACTIVITYPUB_MAX_IMAGE_ATTACHMENTS otherwise. The problem is, that the Ternary Operator sees '0' and 0 as negative/empty/null values and falls back to the default if the user sets 0 as the number of images in the block editor.

Fixes #1818

Proposed changes:

• Check for is_numberic instead of using the Ternary Operator

Other information:

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

Testing instructions:

• See Maximum image attachments ignores 0 #1818 or unittests

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

The image attachment setting now correctly respects a value of 0, instead of falling back to the default.

[Copilot]

Pull Request Overview

This PR fixes the logic for determining the maximum number of image attachments so that a value of 0 is correctly accepted instead of falling back to the default. It replaces the short ternary operator with an explicit is_numeric check.

• Replace ?: fallback with is_numeric check for post meta
• Add corresponding changelog entry

Reviewed Changes

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

File	Description
includes/transformer/class-post.php	Use is_numeric to validate meta before falling back
.github/changelog/1822-from-description	Add patch-level changelog entry

Comments suppressed due to low confidence (1)

includes/transformer/class-post.php:288

• Add a unit test that sets activitypub_max_image_attachments to 0 and verifies that the transformer returns 0 instead of the default value to cover this edge case.

if ( ! is_numeric( $max_media ) ) {