[Distutils] problem with bdist_msi post-install script

["Martin v. Löwis"]

> But this doesn't look quite complete.  I don't see where the Python
> interpreter is actually invoked here.  (Cute trick swapping the args,
> by the way).
> 
> Which is presumably why, in finalize_options, we find:
> 
>         if self.pre_install_script:
>             raise DistutilsOptionError, "the pre-install-script feature is not yet implemented"
> 
> Shouldn't the custom action be this:
> 
>             add_data(self.db, "CustomAction",
>                 [("PreInstall", 2, "PreInstall", '"PYTHON"'),
>                 ])

I don't remember the details, but one problem might have been that
custom action 2 is defined as "EXE file stored in a Binary table
stream." Not sure whether batch files are even allowed here.

In any case, the value should probably be '"[PYTHON]"', then so that the
property gets expanded.

Regards,
Martin