Re: [Bug-wget] [bug-wget] Segfault when trying to use metalinks

[Ángel González]

On 11/09/13 07:13, Darshit Shah wrote:
> I have debugged this a little further.
>
>         I bet an assert(i < opt.jobs <http://opt.jobs>); at
>         multi.c:148 would fail.
>         I'm not sure how this code is supposed to work, but work from
>         there.
>
>     Even, I'm not very aware of the code, but it does seem like the
>     problem  lies there. All the traces point to it.
>
> assert (i < opt.jobs <http://opt.jobs>) would be wrong, since this 
> region of the code is simply calculating the range values based on the 
> chunk_size. A new thread for each range is not being spawned.
>
> The issue was that struct range is defined with int variables, and for 
> file sizes > 4GB, there was an integer overflow. Replacing int with 
> wgint fixes the segfault.
> However, valgrind continues to throw all those invalid write errors, 
> which leads me to believe that the issue is much deeper than this, but 
> I have no idea on where to start debugging this.

The struct would have opt.jobs <http://opt.jobs> items from a quickly 
read of the code, that's why I suggested such assert. The increments to 
the variable i are unbounded, that's why there are writes outside the array.