In `get_page_of_comment()`, use a true `COUNT` query.

This improves memory usage by not compiling a list of comment IDs.

See #34057.
Built from https://develop.svn.wordpress.org/trunk@34661


git-svn-id: http://core.svn.wordpress.org/trunk@34625 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/comment-functions.php

@@ -879,6 +879,7 @@ function get_page_of_comment( $comment_ID, $args = array() ) {
 		'type'       => $args['type'],
 		'post_id'    => $comment->comment_post_ID,
 		'fields'     => 'ids',
+		'count'      => true,
 		'status'     => 'approve',
 		'date_query' => array(
 			array(
@@ -888,8 +889,8 @@ function get_page_of_comment( $comment_ID, $args = array() ) {
 		),
 	);
 
-	$older_comment_ids = get_comments( $comment_args );
-	$older_comment_count = count( $older_comment_ids );
+	$comment_query = new WP_Comment_Query();
+	$older_comment_count = $comment_query->query( $comment_args );
 
 	// No older comments? Then it's page #1.
 	if ( 0 == $older_comment_count )

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-34660';
+$wp_version = '4.4-alpha-34661';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.