Compose AP comment-type exclusion with other plugins' filters

[pfefferle]

Fixes #3306. Also fixes #2849 (same root cause, different query_vars key).

Proposed changes

• Comment::comment_query() now bails only when the caller explicitly requests an AP comment type via type__in / type. In every other case it merges our slugs into type__not_in on top of whatever the caller already set, so AP's exclusion composes with everyone else's filters instead of replacing or abdicating to them.

Why

The previous logic bailed as soon as any of type__in, type, or type__not_in was set on the query, even when the caller's intent had nothing to do with AP types. Two real-world cases broke as a result:

• The way comments and ActivityPub interactions are handled conflict with other Plugins #3306 — GatherPress sets type__in for its own RSVP filtering. AP's filter would see type__in and bail; AP Likes/Reposts/Quotes then leaked into the front-end comment list. Example: https://event-federation.eu/2026/05/15/recurring-events-in-federation/.
• pre_get_comments breaks "manual" WP_Comment_Query->query() calls with type__not_in parameters #2849 — A theme that sets type__not_in for its own exclusion (e.g. 'type__not_in' => 'comment') would have it preserved, but AP types were no longer excluded. Closed previously by switching from "overwrite" to "bail", but bail still leaves AP types visible — the merge is the actual fix.

The merge also continues to honor WP 6.9's built-in 'note' auto-exclusion in WP_Comment_Query::parse_query_vars() — we don't have to add 'note' ourselves.

Other information

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

Three new tests in Test_Comment:

• test_comment_query_merges_ap_exclusion_with_existing_type_in — sets type__in => [ 'gatherpress_rsvp' ], asserts type__not_in ends up containing like and repost. This is the GatherPress regression.
• test_comment_query_merges_ap_exclusion_with_existing_type_not_in — sets type__not_in => [ 'pingback' ], asserts both pingback and the AP slugs are present after the filter. This is the pre_get_comments breaks "manual" WP_Comment_Query->query() calls with type__not_in parameters #2849 regression.
• test_comment_query_respects_explicit_ap_type_request — sets type__in => [ 'like' ], asserts the filter does not push like into type__not_in. Escape hatch for callers who want AP comments back.

All 70 Test_Comment tests pass locally (228 assertions).

Testing instructions

1. Install GatherPress alongside ActivityPub on a site with a federated post that has AP Likes/Reposts comments attached.
2. Visit the post's front-end singular page on trunk: AP Likes/Reposts/Quotes appear in the comment list.
3. Pull this branch, reload: the AP comments are gone, while GatherPress's own RSVP filtering still works.
4. Repeat for any theme that uses type__not_in in its comment template (the pre_get_comments breaks "manual" WP_Comment_Query->query() calls with type__not_in parameters #2849 shape).

Changelog entry

Already added at `.github/changelog/fix-comment-query-type-coexistence`.

[Copilot]

Pull request overview

Fixes regressions where the ActivityPub pre_get_comments handler bailed out as soon as any of type__in, type, or type__not_in was set on a comment query, allowing AP Likes/Reposts/Quotes to leak into front-end comment lists when other plugins/themes (e.g., GatherPress) used those query vars. The handler now merges AP comment-type slugs into type__not_in while still respecting callers that explicitly request an AP type.

Changes:

• Rewrote Comment::comment_query() to merge AP slugs into type__not_in rather than bailing, with an escape hatch when type__in/type explicitly names an AP type.
• Added three PHPUnit tests covering merge-with-type__in, merge-with-type__not_in, and explicit AP type requests.
• Added a patch/fixed changelogger entry.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
includes/class-comment.php	Replaces early-bail logic with type-merge logic that composes with other plugins' filters.
tests/phpunit/tests/includes/class-test-comment.php	New tests for type__in merge, type__not_in merge, and explicit AP type request.
.github/changelog/fix-comment-query-type-coexistence	Changelog entry describing the front-end leak fix.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

[pfefferle]

@Menrath does that fix the issue!?

[Menrath]

@Menrath does that fix the issue!?

I will test this in a minute! :)

[Menrath]

@pfefferle Could you rebase this PR on the lasted updates, my blog already is on 8.3.0 :)

[pfefferle]

@Menrath done!

[Menrath]

Hmm, I just deployed this branch and still the ...liked this comments show up. https://event-federation.eu/2026/05/15/recurring-events-in-federation/

[pfefferle]

So maybe it is a Gatherpress issue then, because they ignore the ActivityPub excludes?

[pfefferle]

Can you try to call the query filter later in the queue? Maybe:

\add_action( 'pre_get_comments', array( static::class, 'comment_query' ), 50 );

[Menrath]

The other way round it worked:

\add_action( 'pre_get_comments', array( static::class, 'comment_query' ), 5 );

And in GatherPress:

add_action( 'pre_get_comments', array( $this, 'exclude_rsvp_from_comment_query' ), 10 );

/**
	 * Exclude RSVP comments from a query.
	 *
	 * This method modifies the comment query to exclude comments of the RSVP type. It
	 * ensures that RSVP comments are not included in the query results by adjusting the
	 * comment types in the query variables.
	 *
	 * Note: The comment_type field is not currently indexed in WordPress core,
	 * which may impact query performance. See https://core.trac.wordpress.org/ticket/59488
	 *
	 * @since 1.0.0
	 *
	 * @param WP_Comment_Query $query Current instance of WP_Comment_Query (passed by reference).
	 * @return void
	 */
	public function exclude_rsvp_from_comment_query( WP_Comment_Query $query ) {
		// Process 'type' query var.
		$current_comment_types = $query->query_vars['type'];

		if ( ! empty( $current_comment_types ) ) {
			if ( is_array( $current_comment_types ) ) {
				$current_comment_types = array_values(
					array_diff( $current_comment_types, array( Rsvp::COMMENT_TYPE ) )
				);
			} elseif ( Rsvp::COMMENT_TYPE === $current_comment_types ) {
				$current_comment_types = '';
			}
		} else {
			// Get all registered comment types from the database (cached).
			$current_comment_types = $this->get_all_comment_types();
			$current_comment_types = array_values( array_diff( $current_comment_types, array( Rsvp::COMMENT_TYPE ) ) );
		}

		$query->query_vars['type'] = $current_comment_types;

		// Process 'type__in' query var.
		$current_comment_types_in = $query->query_vars['type__in'];

		if ( ! empty( $current_comment_types_in ) ) {
			if ( is_array( $current_comment_types_in ) ) {
				$current_comment_types_in = array_values(
					array_diff( $current_comment_types_in, array( Rsvp::COMMENT_TYPE ) )
				);
			} elseif ( Rsvp::COMMENT_TYPE === $current_comment_types_in ) {
				$current_comment_types_in = '';
			}

			$query->query_vars['type__in'] = $current_comment_types_in;
		}
	}

CC @mauteri