Use `WP_Query` when sending pingbacks.

Props dshanske, spacedmonkey, janw.oostendorp, mrmadhat, birgire.
See #36824.
Built from https://develop.svn.wordpress.org/trunk@46177


git-svn-id: http://core.svn.wordpress.org/trunk@45989 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/comment.php

@@ -2633,10 +2633,20 @@ function discover_pingback_server_uri( $url, $deprecated = '' ) {
 function do_all_pings() {
 	global $wpdb;
 
-	// Do pingbacks
-	while ( $ping = $wpdb->get_row( "SELECT ID, post_content, meta_id FROM {$wpdb->posts}, {$wpdb->postmeta} WHERE {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id AND {$wpdb->postmeta}.meta_key = '_pingme' LIMIT 1" ) ) {
-		delete_metadata_by_mid( 'post', $ping->meta_id );
-		pingback( $ping->post_content, $ping->ID );
+	// Do pingbacks.
+	$pings = get_posts(
+		array(
+			'post_type'        => get_post_types(),
+			'suppress_filters' => false,
+			'nopaging'         => true,
+			'meta_key'         => '_pingme',
+			'fields'           => 'ids',
+		)
+	);
+
+	foreach ( $pings as $ping ) {
+		delete_post_meta( $ping, '_pingme' );
+		pingback( null, $ping );
 	}
 
 	// Do enclosures.

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.3-alpha-46176';
+$wp_version = '5.3-alpha-46177';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.