[pacman-dev] [BUG] alpm_list_remove need an initalized pointer for void **data

[Xavier]

On Thu, Aug 7, 2008 at 5:23 PM, solsTiCe d'Hiver
<solstice.dhiver at gmail.com> wrote:
> for me it is a problem with alpm_list_remove but i am not an expert.
>

And Dan is an expert so he must be right :)

> look at this
> #include <alpm.h>
>
> int compare_int(const void *a, const void *b) {
>    const int* ia = (const int *)a;
>    const int* ib = (const int *)b;
>    return (*ia > *ib) - (*ia < *ib);
> }
>
> int main(void) {
>    alpm_list_t *l=NULL;
>    int a=2,a2=2;
>    l= alpm_list_add(l, &a);
>    l= alpm_list_add(l, &a2);
>    void **data=NULL;
>    l = alpm_list_remove(l, &a, compare_int, data);
>    puts("still ok ?");
>    void **data2;
>    l = alpm_list_remove(l, &a2, compare_int, data2);
>    return 0;
> }
>
> it only seg fault at the second alpm_list_remove

Indeed, this second example segfault in list_remove. But not your
first one, which segfaults on the fn(...) call inside list_remove.
And the fn parameter is _alpm_db_cmp.

Try this :
   void *data;
   l = alpm_list_remove(l, &a, compare_int, &data);
   void *data2;
   l = alpm_list_remove(l, &a2, compare_int, &data2);