Ticket #19538: 19538.2.diff

wp-admin/includes/ms.php

@@ -385 +385 @@
  */
 function get_space_allowed() {
         $space_allowed = get_option( 'blog_upload_space' );
-        if ( $space_allowed === false )
+
+        if ( $space_allowed === false || $space_allowed === '' )
                 $space_allowed = get_site_option( 'blog_upload_space' );
-        if ( empty( $space_allowed ) || !is_numeric( $space_allowed ) )
+        if ( $space_allowed === false || $space_allowed === '' || !is_numeric( $space_allowed ) )
                 $space_allowed = 50;
 
         return $space_allowed;