[En-Nut-Discussion] DNS fix

[Michel]

Hi Oliver,

Oops, yes, you are right about my modifications being useless.
But only in 3 places where my fixes are useless:
the last lines in ReleaseDnsHeader, ReleaseDnsQuestion() and
ReleaseDnsResource().

I checked it and all other places where I set pointers to 0 prevent
them from being freed twice.
E.g. adding dor->dor_name = 0; and dor->dor_data = 0 to ReleaseDnsResource()
DOES prevent freeing twice. (Right?)

Greetings,
Michel

> -----Original Message-----
> From: en-nut-discussion-bounces at egnite.de 
> [mailto:en-nut-discussion-bounces at egnite.de] On Behalf Of 
> Oliver Schulz
> Sent: donderdag 15 april 2004 20:30
> To: 'Ethernut User Chat (English)'
> Subject: AW: [En-Nut-Discussion] DNS fix
> 
> 
> Hi Michel,
> > - Prevent freeing twice
> Sorry to say that, but your modifications are are useless.
> If you assign a value to a function parameter, which is 
> stored normally on stack or in a register, this value is 
> destroyed after the function returns, because it is just a 
> copy of the passed parameter. If you want to alter the 
> parameter itself, you have to pass it as a pointer, like in 
> this example:
> 
> static void ReleaseDnsHeader(DNSHEADER ** doh)
> {
>     if (*doh) {
>         NutHeapFree(*doh);
>         *doh = 0;
>     }
> }
> 
> Regards,
> Oliver.
> 
> _______________________________________________
> En-Nut-Discussion mailing list
> En-Nut-Discussion at egnite.de 
> http://www.egnite.de/mailman/listinfo.cgi/en-nut-> discussion
> 
>