[vlc-devel] [PATCH 1/2] httplive: fix Read func. (when caller skips data)

[Hugo Beauzée-Luyssen]

On Wed, Feb 1, 2012 at 12:13 PM, Jean-Baptiste Kempf <jb at videolan.org> wrote:
> On Tue, Jan 31, 2012 at 01:32:22PM +0100, Frederic YHUEL wrote :
>> -            memcpy(p_read + copied, segment->data->p_buffer, len);
>> +            if( p_read ) /* otherwise caller skips data */
>> +                memcpy(p_read + copied, segment->data->p_buffer, len);
>
> The code seems wrong if hls_read can be called with p_read at NULL.
> Use assert then.
>
>> -    if (buffer == NULL)
>> -    {
>> -        /* caller skips data, get big enough buffer */
>> -        msg_Warn(s, "buffer is NULL (allocate %d)", i_read);
>> -        buffer = calloc(1, i_read);
>> -        if (buffer == NULL)
>> -            return 0; /* NO MEMORY left*/
>> -    }
>
> What guarrantees us that the buffer will not be NULL ?
>
> Best regards,
>

If I'm not mistaking, the all point is to allow buffer to be NULL.
This patch looks correct to me, I don't see the point in allocating
memory and copying data to it if the data is to be skipped.
Maybe adding a comment stating that p_read may be NULL at the
beginning of the hls_Read function would be better, so one doesn't
assume p_read is always != NULL

Regards,

-- 
Hugo Beauzée-Luyssen