Users: Add the `pre_count_users` filter.

Props spacedmonkey.
Fixes #43693.


Built from https://develop.svn.wordpress.org/trunk@44473


git-svn-id: http://core.svn.wordpress.org/trunk@44304 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/user.php

@@ -882,6 +882,24 @@ function count_users( $strategy = 'time', $site_id = null ) {
 	if ( ! $site_id ) {
 		$site_id = get_current_blog_id();
 	}
+
+	/**
+	 * Filter the user count before queries are run. Return a non-null value to cause count_users()
+	 * to return early.
+	 *
+	 * @since 5.1.0
+	 *
+	 * @param null|string $result   Default null.
+	 * @param string      $strategy Optional. The computational strategy to use when counting the users.
+	 *                              Accepts either 'time' or 'memory'. Default 'time'.
+	 * @param int|null    $site_id  Optional. The site ID to count users for. Defaults to the current site.
+	 */
+	$pre = apply_filters( 'pre_count_users', null, $strategy, $site_id );
+
+	if ( null !== $pre ) {
+		return $pre;
+	}
+
 	$blog_prefix = $wpdb->get_blog_prefix( $site_id );
 	$result      = array();
 

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.1-alpha-44472';
+$wp_version = '5.1-alpha-44473';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.