Docs: Document globals in validate_another_blog_signup().

Props mukesh27.
Fixes #43594.

Built from https://develop.svn.wordpress.org/trunk@43326


git-svn-id: http://core.svn.wordpress.org/trunk@43154 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-43325';
+$wp_version = '5.0-alpha-43326';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.

wp-signup.php

@@ -368,7 +368,13 @@ function signup_another_blog( $blogname = '', $blog_title = '', $errors = '' ) {
 }
 
 /**
- * Validate a new site signup.
+ * Validate a new site signup for an existing user.
+ *
+ * @global string          $blogname   The new site's subdomain or directory name.
+ * @global string          $blog_title The new site's title.
+ * @global WP_Error        $errors     Existing errors in the global scope.
+ * @global string          $domain     The new site's domain.
+ * @global string          $path       The new site's path.
  *
  * @since MU (3.0.0)
  *