[sane-devel] [patch] fix SANE_Device

[Oliver Rauch]

Am Sam, 2004-11-13 um 21.26 schrieb Frank Zago:

> > I guess the idea was that the strings shouldn't be changed after the
> > SANE-Device pointer is returned to the frontend.
> 
> Thsi behaviour should be made clear in the doc. To me, const means something else.
> Since this patch makes the variable from const to non-const, I don't think it 
> will break anything.
> 
> > 
> > As far as I can see the trouble results from doing things like
> > sane.name = strdup (...) and freeing those in sane_exit().
> > 
> 
> That is correct. I think it's clear from the use of that field that the const 
> creates more trouble than it solves.

Hello Henning, hello Frank,

I think the const should not be changed because of two reasons:

1) It makes sense to define it as const in the standard because
   the frontend should not change anything in the struct that
   is returned by the backend
2) It is part of the sane standard and it makes a lot of problems
   to change the standard definitions

May be we need a second definition without the const in some cases,
but the struct that is returned by the backend should contain const
strings.

So when it is necessary then the routine that needs any non const
strings has to create its own struct definition.

May be this second (non const) definition can be put in a helper file
(sanei_???.h).

Oliver