Leave PHP on code edit

In my site y need to insert images without absolute url, so I use the PHP code "base_path()" like in this example:

<img src="<?= bas_path()?>images/picture.jpg" alt="Some Picture" />

So I use the editor in code view to write this code. But when I save the node the PHP is always removed by widgEdit, even if Drupal 6 input format is set to allow PHP.

I can see 2 possibles solutions:

1. Make widgEdit leave alone the PHP code when the Drupal 6 input format is set on PHP code.
2. Or, add a link to quick disable the rich text editor (like the one you see to enable the editor, when you setup the module to not be active by default).

Y suppose the option 2 it can be implemented relatively easy.

Thank!