[pfefferle]

Fixes #

Proposed changes:

• Custom emoji are found by their shortcode (:name:) in one pass over the text, and each one is looked up in the emoji of the post or the actor.
• A shortcode has letters, digits, _ and -, 2 to 100 characters. Emoji with other names are not stored and stay text.
• A shortcode needs a space or punctuation around it, so text like 12:30:blobcat: stays as it is.
• Shortcodes match regardless of case, as before.
• An author name only prepares the emoji it uses.
• Emoji blocks in replies are built with core's get_comment_delimited_block_content().

Other information:

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

Testing instructions:

• Reply to a post from an account that has a custom emoji in its display name, and use another custom emoji in the reply: both show as images.
• Use the shortcode in a different case in the reply (:Blobcat: for :blobcat:): it still shows.
• npm run env-test -- --filter Test_Emoji

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

[Copilot]

🟡 Changes recommended

An unmapped shortcode can consume the opening colon of a valid emoji, preventing it from rendering in replies and author names; both replacement paths need a fix and regression coverage.

1 open issue

• Unknown shortcodes block adjacent valid emoji replacement · New

What changed in this PR

This PR updates custom emoji rendering in replies and author names to use shortcode lookup with a fixed matching pattern.

Changes:

• Validates shortcode names and preserves case-insensitive matching.
• Prepares only emoji used in author names and uses WordPress’s block serialization helper for replies.
• Adds regression tests and a security changelog entry.

File	Description
tests/​phpunit/​tests/​includes/​class-test-emoji.php	Tests validation, large emoji sets, case-insensitive matching, and unused emoji handling.
includes/​class-emoji.php	Adds shared shortcode validation and replacement, filters stored emoji, and updates block serialization.
.github/​changelog/​fix-emoji-replacement	Documents improved emoji rendering in names and replies.

_{Review effort: Balanced}

[Copilot]

🟢 Approval recommended

No active review issues block approval of the emoji shortcode-handling changes.

No open issues 🎉

1 resolved since last review

• Unknown shortcodes block adjacent valid emoji replacement

_{Review effort: Balanced}