Use SCRIPT_NAME instead of PHP_SELF which won't send the PATH_INFO, this prevents XSS in old browsers. Thanks to Nico Golde.

Fixes a bug where if one tries to delete a file, then clicks undo, and then tries to delete the file again, no questions or undo options were presented.

Essentially, just set FileLists.lastAction = null when one clicks undo.

Use SCRIPT_NAME instead of PHP_SELF which won't send the PATH_INFO, this prevents XSS in old browsers. Thanks to Nico Golde.