Comments: Add filter for comment types excluded from queries by default

src/wp-admin/includes/class-wp-comments-list-table.php

@@ -103,12 +103,48 @@ public function prepare_items() {
 			$comment_status = 'all';
 		}
 
+		/*
+		 * Notes carry their own visibility rules, so they are never listed here and a
+		 * request for them is dropped outright. This is deliberately narrower than the
+		 * treatment of the other default-excluded types below, which can be listed when
+		 * explicitly requested. Emptying the excluded set does surface notes in the
+		 * untyped views, but not as a type the table can be filtered to.
+		 */
 		$comment_type = '';
 
 		if ( ! empty( $_REQUEST['comment_type'] ) && 'note' !== $_REQUEST['comment_type'] ) {
 			$comment_type = $_REQUEST['comment_type'];
 		}
 
+		/*
+		 * WP_Comment_Query drops the default exclusions when 'all' types are
+		 * requested, so they are also passed as 'type__not_in' to keep excluded
+		 * types out of the list table in that case.
+		 *
+		 * The requested type is removed from that list, so a plugin that adds
+		 * its own default-excluded type to the type dropdown via
+		 * 'admin_comment_types_dropdown' can still list it. Type aliases are
+		 * expanded first, matching how WP_Comment_Query resolves them.
+		 */
+		switch ( $comment_type ) {
+			// Kept for symmetry with WP_Comment_Query; the accessor strips these tokens
+			// from the excluded set, so this branch can never subtract anything.
+			case 'comment':
+			case 'comments':
+				$requested_types = array( '', 'comment' );
+				break;
+
+			case 'pings':
+				$requested_types = array( 'pingback', 'trackback' );
+				break;
+
+			default:
+				$requested_types = array( $comment_type );
+				break;
+		}
+
+		$excluded_types = array_values( array_diff( wp_get_default_excluded_comment_types(), $requested_types ) );
+
 		$search = $_REQUEST['s'] ?? '';
 
 		$post_type = ( isset( $_REQUEST['post_type'] ) ) ? sanitize_key( $_REQUEST['post_type'] ) : '';
@@ -155,7 +191,7 @@ public function prepare_items() {
 			'number'                    => $number,
 			'post_id'                   => $post_id,
 			'type'                      => $comment_type,
-			'type__not_in'              => array( 'note' ),
+			'type__not_in'              => $excluded_types,
 			'orderby'                   => $orderby,
 			'order'                     => $order,
 			'post_type'                 => $post_type,

src/wp-admin/includes/comment.php

@@ -223,6 +223,8 @@ function get_comment_to_edit( $id ) {
  *
  * @since 2.3.0
  * @since 6.9.0 Exclude the 'note' comment type from the count.
+ * @since 7.2.0 The excluded comment types are derived from the
+ *              {@see 'default_excluded_comment_types'} filter.
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
@@ -242,7 +244,11 @@ function get_pending_comments_num( $post_id ) {
 	$post_id_array = array_map( 'intval', $post_id_array );
 	$post_id_in    = "'" . implode( "', '", $post_id_array ) . "'";
 
-	$pending = $wpdb->get_results( "SELECT comment_post_ID, COUNT(comment_ID) as num_comments FROM $wpdb->comments WHERE comment_post_ID IN ( $post_id_in ) AND comment_approved = '0' AND comment_type != 'note' GROUP BY comment_post_ID", ARRAY_A );
+	$type_not_in = _wp_get_excluded_comment_types_clause();
+
+	// $post_id_in is built from integers and $type_not_in is prepared above.
+	// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
+	$pending = $wpdb->get_results( "SELECT comment_post_ID, COUNT(comment_ID) as num_comments FROM $wpdb->comments WHERE comment_post_ID IN ( $post_id_in ) AND comment_approved = '0'$type_not_in GROUP BY comment_post_ID", ARRAY_A );
 
 	if ( $single ) {
 		if ( empty( $pending ) ) {

src/wp-includes/class-wp-comment-query.php

@@ -66,6 +66,17 @@ class WP_Comment_Query {
 	 */
 	protected $filtered_where_clause;
 
+	/**
+	 * Comment types excluded from the results by default.
+	 *
+	 * Resolved once per query in get_comments(), so that the set folded into the cache
+	 * key is the same one get_comment_ids() builds the SQL from. Null until resolved.
+	 *
+	 * @since 7.2.0
+	 * @var string[]|null
+	 */
+	protected $default_excluded_comment_types = null;
+
 	/**
 	 * Date query container
 	 *
@@ -455,6 +466,18 @@ public function get_comments() {
 		$_args = wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) );
 		unset( $_args['fields'], $_args['update_comment_meta_cache'], $_args['update_comment_post_cache'] );
 
+		/*
+		 * The default-excluded types are not query vars, but they do change the results,
+		 * so they belong in the key. Without them a persistent object cache would keep
+		 * serving entries built before a plugin changed the excluded set, since changing
+		 * it does not touch the comment 'last_changed' value the key is salted with.
+		 *
+		 * The resolved set is reused in get_comment_ids() so the filter runs once per query.
+		 */
+		$this->default_excluded_comment_types = wp_get_default_excluded_comment_types( $this );
+
+		$_args['default_excluded_comment_types'] = $this->default_excluded_comment_types;
+
 		$key          = md5( serialize( $_args ) );
 		$last_changed = wp_cache_get_last_changed( 'comment' );
 
@@ -544,6 +567,7 @@ public function get_comments() {
 	 *
 	 * @since 4.4.0
 	 * @since 6.9.0 Excludes the 'note' comment type, unless 'all' or the 'note' types are requested.
+	 * @since 7.2.0 The default-excluded comment types are filterable via {@see 'default_excluded_comment_types'}.
 	 *
 	 * @global wpdb $wpdb WordPress database abstraction object.
 	 *
@@ -779,13 +803,45 @@ protected function get_comment_ids() {
 			'NOT IN' => (array) $this->query_vars['type__not_in'],
 		);
 
-		// Exclude the 'note' comment type, unless 'all' types or the 'note' type explicitly are requested.
-		if (
-			! in_array( 'all', $raw_types['IN'], true ) &&
-			! in_array( 'note', $raw_types['IN'], true ) &&
-			! in_array( 'note', $raw_types['NOT IN'], true )
-		) {
-			$raw_types['NOT IN'][] = 'note';
+		// Resolved in get_comments() when the cache key is built; resolve here for direct calls.
+		if ( null === $this->default_excluded_comment_types ) {
+			$this->default_excluded_comment_types = wp_get_default_excluded_comment_types( $this );
+		}
+
+		$excluded_types = $this->default_excluded_comment_types;
+
+		// Unless all types are requested, exclude each default-excluded type
+		// that the query does not explicitly request. The special type tokens
+		// in the request ('comment', 'comments', 'pings') are first expanded to
+		// the literal comment_type values they represent, so a type requested
+		// via an alias (for example 'pings' for 'pingback' and 'trackback') is
+		// still treated as explicitly requested and is not excluded.
+		if ( ! in_array( 'all', $raw_types['IN'], true ) ) {
+			$requested_types = array();
+			foreach ( $raw_types['IN'] as $requested_type ) {
+				switch ( $requested_type ) {
+					case 'comment':
+					case 'comments':
+						$requested_types[] = '';
+						$requested_types[] = 'comment';
+						break;
+
+					case 'pings':
+						$requested_types[] = 'pingback';
+						$requested_types[] = 'trackback';
+						break;
+
+					default:
+						$requested_types[] = $requested_type;
+						break;
+				}
+			}
+
+			foreach ( $excluded_types as $excluded_type ) {
+				if ( ! in_array( $excluded_type, $requested_types, true ) ) {
+					$raw_types['NOT IN'][] = $excluded_type;
+				}
+			}
 		}
 
 		$comment_types = array();

src/wp-includes/class-wp-query.php

@@ -2825,13 +2825,15 @@ public function get_posts() {
 
 		// Comments feeds.
 		if ( $this->is_comment_feed && ! $this->is_singular ) {
+			$ctype_not_in = _wp_get_excluded_comment_types_clause( "{$wpdb->comments}.comment_type" );
+
 			if ( $this->is_archive || $this->is_search ) {
 				$cjoin    = "JOIN {$wpdb->posts} ON ( {$wpdb->comments}.comment_post_ID = {$wpdb->posts}.ID ) $join ";
-				$cwhere   = "WHERE comment_approved = '1' AND {$wpdb->comments}.comment_type != 'note' $where";
+				$cwhere   = "WHERE comment_approved = '1'$ctype_not_in $where";
 				$cgroupby = "{$wpdb->comments}.comment_id";
 			} else { // Other non-singular, e.g. front.
 				$cjoin    = "JOIN {$wpdb->posts} ON ( {$wpdb->comments}.comment_post_ID = {$wpdb->posts}.ID )";
-				$cwhere   = "WHERE ( post_status = 'publish' OR ( post_status = 'inherit' AND post_type = 'attachment' ) ) AND comment_approved = '1' AND {$wpdb->comments}.comment_type != 'note'";
+				$cwhere   = "WHERE ( post_status = 'publish' OR ( post_status = 'inherit' AND post_type = 'attachment' ) ) AND comment_approved = '1'$ctype_not_in";
 				$cgroupby = '';
 			}
 
@@ -3485,11 +3487,13 @@ public function get_posts() {
 		}
 
 		if ( ! empty( $this->posts ) && $this->is_comment_feed && $this->is_singular ) {
+			$ctype_not_in = _wp_get_excluded_comment_types_clause( "{$wpdb->comments}.comment_type" );
+
 			/** This filter is documented in wp-includes/class-wp-query.php */
 			$cjoin = apply_filters_ref_array( 'comment_feed_join', array( '', &$this ) );
 
 			/** This filter is documented in wp-includes/class-wp-query.php */
-			$cwhere = apply_filters_ref_array( 'comment_feed_where', array( "WHERE comment_post_ID = '{$this->posts[0]->ID}' AND comment_approved = '1' AND {$wpdb->comments}.comment_type != 'note'", &$this ) );
+			$cwhere = apply_filters_ref_array( 'comment_feed_where', array( "WHERE comment_post_ID = '{$this->posts[0]->ID}' AND comment_approved = '1'$ctype_not_in", &$this ) );
 
 			/** This filter is documented in wp-includes/class-wp-query.php */
 			$cgroupby = apply_filters_ref_array( 'comment_feed_groupby', array( '', &$this ) );

src/wp-includes/comment-template.php

@@ -755,6 +755,7 @@ function comment_ID() { // phpcs:ignore WordPress.NamingConventions.ValidFunctio
  *
  * @since 1.5.0
  * @since 4.4.0 Added the ability for `$comment` to also accept a WP_Comment object. Added `$cpage` argument.
+ * @since 7.2.0 The default 'type' changed from 'all' to '', matching get_page_of_comment().
  *
  * @see get_page_of_comment()
  *
@@ -786,7 +787,7 @@ function get_comment_link( $comment = null, $args = array() ) {
 	}
 
 	$defaults = array(
-		'type'      => 'all',
+		'type'      => '',
 		'page'      => '',
 		'per_page'  => '',
 		'max_depth' => '',