Ticket #45800: 45800.diff

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

@@ -379 +379 @@
                         $this->meta_query_clauses = $this->meta_query->get_sql( 'comment', $wpdb->comments, 'comment_ID', $this );
                 }
 
-                /*
-                 * Only use the args defined in the query_var_defaults to compute the key,
-                 * but ignore 'fields', which does not affect query results.
+                /**
+                 * Filters the comments array before the query takes place.
+                 *
+                 * Return a non-null value to bypass WordPress's default comment queries.
+                 *
+                 * @since x.x.x
+                 *
+                 * @param array|int|null   $results Return null to allow WP to run its normal queries.
+                 *                                  Otherwise, return an array of comment data,
+                 *                                  an array of int if `fields=ids` or
+                 *                                  an int if `count=true` to short-circuit WP's comment query.
+                 * @param WP_Comment_Query  $this   The WP_Comment_Query instance (passed by reference).
                  */
-                $_args = wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) );
-                unset( $_args['fields'] );
+                $this->comments = apply_filters_ref_array( 'comments_pre_query', array( null, &$this ) );
 
-                $key          = md5( serialize( $_args ) );
-                $last_changed = wp_cache_get_last_changed( 'comment' );
+                $comment_ids = array();
 
-                $cache_key   = "get_comments:$key:$last_changed";
-                $cache_value = wp_cache_get( $cache_key, 'comment' );
-                if ( false === $cache_value ) {
-                        $comment_ids = $this->get_comment_ids();
-                        if ( $comment_ids ) {
-                                $this->set_found_comments();
+                if ( null === $this->comments ) {
+                        // $args can include anything. Only use the args defined in the query_var_defaults to compute the key.
+                        $_args = wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) );
+
+                        // Ignore the $fields argument as the queried result will be the same regardless.
+                        unset( $_args['fields'] );
+
+                        $key          = md5( serialize( $_args ) );
+                        $last_changed = wp_cache_get_last_changed( 'comment' );
+
+                        $cache_key   = "get_comments:$key:$last_changed";
+                        $cache_value = wp_cache_get( $cache_key, 'comment' );
+                        if ( false === $cache_value ) {
+                                $comment_ids = $this->get_comment_ids();
+                                if ( $comment_ids ) {
+                                        $this->set_found_comments();
+                                }
+
+                                $cache_value = array(
+                                        'comment_ids'    => $comment_ids,
+                                        'found_comments' => $this->found_comments,
+                                );
+                                wp_cache_add( $cache_key, $cache_value, 'comment' );
+                        } else {
+                                $comment_ids          = $cache_value['comment_ids'];
+                                $this->found_comments = $cache_value['found_comments'];
                         }
-
-                        $cache_value = array(
-                                'comment_ids'    => $comment_ids,
-                                'found_comments' => $this->found_comments,
-                        );
-                        wp_cache_add( $cache_key, $cache_value, 'comment' );
-                } else {
-                        $comment_ids          = $cache_value['comment_ids'];
-                        $this->found_comments = $cache_value['found_comments'];
                 }
 
                 if ( $this->found_comments && $this->query_vars['number'] ) {
@@ -413 +431 @@
 
                 // If querying for a count only, there's nothing more to do.
                 if ( $this->query_vars['count'] ) {
-                        // $comment_ids is actually a count in this case.
-                        return intval( $comment_ids );
+                        if ( null === $this->comments ) {
+                                // $comment_ids is actually a count in this case.
+                                return intval( $comment_ids );
+                        }
+                        // The comments_pre_query callback should be smart enough to test it and return the right result.
+                        return intval( $this->comments );
                 }
 
                 $comment_ids = array_map( 'intval', $comment_ids );
 
                 if ( 'ids' == $this->query_vars['fields'] ) {
-                        $this->comments = $comment_ids;
+                        if ( null === $this->comments ) {
+                                $this->comments = $comment_ids;
+                        }
                         return $this->comments;
                 }
 
-                _prime_comment_caches( $comment_ids, $this->query_vars['update_comment_meta_cache'] );
+                if ( null === $this->comments ) {
+                        _prime_comment_caches( $comment_ids, $this->query_vars['update_comment_meta_cache'] );
 
-                // Fetch full comment objects from the primed cache.
-                $_comments = array();
-                foreach ( $comment_ids as $comment_id ) {
-                        if ( $_comment = get_comment( $comment_id ) ) {
-                                $_comments[] = $_comment;
+                        // Fetch full comment objects from the primed cache.
+                        $_comments = array();
+                        foreach ( $comment_ids as $comment_id ) {
+                                if ( $_comment = get_comment( $comment_id ) ) {
+                                        $_comments[] = $_comment;
+                                }
                         }
-                }
 
-                // Prime comment post caches.
-                if ( $this->query_vars['update_comment_post_cache'] ) {
-                        $comment_post_ids = array();
-                        foreach ( $_comments as $_comment ) {
-                                $comment_post_ids[] = $_comment->comment_post_ID;
+                        // Prime comment post caches.
+                        if ( $this->query_vars['update_comment_post_cache'] ) {
+                                $comment_post_ids = array();
+                                foreach ( $_comments as $_comment ) {
+                                        $comment_post_ids[] = $_comment->comment_post_ID;
+                                }
+
+                                _prime_post_caches( $comment_post_ids, false, false );
                         }
-
-                        _prime_post_caches( $comment_post_ids, false, false );
+                } else {
+                        $_comments = $this->comments;
                 }
 
                 /**
@@ -457 +485 @@
                 // Convert to WP_Comment instances
                 $comments = array_map( 'get_comment', $_comments );
 
-                if ( $this->query_vars['hierarchical'] ) {
-                        $comments = $this->fill_descendants( $comments );
+                if ( null === $this->comments ) {
+                        if ( $this->query_vars['hierarchical'] ) {
+                                $comments = $this->fill_descendants( $comments );
+                        }
                 }
 
                 $this->comments = $comments;

tests/phpunit/tests/comment/query.php

@@ -4882 +4882 @@
 
                 $this->assertEqualSets( $c1, $found );
         }
+
+        /**
+         * @ticket 45800
+         */
+        public function test_comments_pre_query_filter_should_bypass_database_query() {
+                global $wpdb;
+
+                add_filter( 'comments_pre_query', array( __CLASS__, 'filter_comments_pre_query' ), 10, 2 );
+
+                $num_queries = $wpdb->num_queries;
+                $q           = new WP_Comment_Query(
+                        array(
+                                'fields' => 'ids',
+                        )
+                );
+
+                remove_filter( 'comments_pre_query', array( __CLASS__, 'filter_comments_pre_query' ), 10, 2 );
+
+                // Make sure no queries were executed.
+                $this->assertSame( $num_queries, $wpdb->num_queries );
+
+                // We manually inserted a non-existing comment ID and overrode the results with it.
+                $this->assertSame( array( 555 ), $q->comments );
+
+                // Make sure manually setting found_comments doesn't get overwritten.
+                $this->assertEquals( 1, $q->found_comments );
+        }
+
+        public static function filter_comments_pre_query( $comments, $query ) {
+                $query->found_comments = 1;
+
+                return array( 555 );
+        }
 }