Ticket #32135: 32135-1.diff

src/wp-admin/includes/file.php

@@ -146 +146 @@
                 $dir = get_temp_dir();
         }
 
-        if ( empty( $filename ) || '.' == $filename ) {
+        if ( empty( $filename ) || '.' == $filename || '/' === $filename ) {
                 $filename = time();
         }