On 14 Oct 2006 07:45:42 -0700, email@example.com
> For a kiosk application I need to suppress all instances of
> nsHelperAppDlg and nsFilePicker. I have managed to do this by stripping
> all code from the functions in the JS files, leaving just the interface
> definitions and default return values. But this seems quite hackish and
> unstable to me. Is there any way to write a regular extension that
> returns a "dummy" object when an Instance of
> "@mozilla.org/helperapplauncherdialog;1" is created?
You can write a dummy XPCOM component implementing the necessary
interfaces and register it with the sane contract id.