Re: [PATCH] Don't multiply by -1 when assigning memory

[Tim Janik <timj gtk org>]

On Thu, 5 Jan 2006, Rodrigo Moya wrote:

> On Thu, 2006-01-05 at 18:43 +0800, James Henstridge wrote:
> > Rodrigo Moya wrote:
> >
> > > > What Matthias is saying is that in the case of zero args, you don't need
> > > > to allocate the full size of GtkBindingSignal: you don't need to
> > > > GtkBindingArg embedded at the end of the struct.  So the correct answer
> > > > would probably be:
> > > >  sizeof (GtkBindingSignal) + n_args * sizeof (GtkBindingArg) - sizeof
> > > > (GtkBindingArg)
> > > hmm, but if I understand it correctly, this would yield an invalid value
> > > when n_args = 0, since it would be:
> > >
> > > sizeof (GtkBindingSignal) + 0 * sizeof (GtkBindingArg) - sizeof
> > > (GtkBindingArg)
> > >
> > > which will be:
> > >
> > > sizeof (GtkBindingSignal) + sizeof (GtkBindingArg)
> > It would actually be:
> >     sizeof (GtkBindingSignal) - sizeof (GtkBindingArg)
> yes, sorry, mistyped it.
>
> > > is that what we want?
> > Yes.  That allocates enough space for everything except the 1-element
> > GtkBindingArg array at the end of the structure, which is not a problem
> > if n_args is 0.
> ok, patch attached

> -  signal = (GtkBindingSignal *) g_slice_alloc0 (sizeof (GtkBindingSignal) + n_args * sizeof (GtkBindingArg));
> +  signal = (GtkBindingSignal *) g_slice_alloc0 (sizeof (GtkBindingSignal) + n_args * sizeof (GtkBindingArg) - sizeof (GtkBindingArg));

thanks, rodrigo, please apply.

> --
> Rodrigo Moya <rodrigo gnome-db org>

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ciaoTJ