[DVDnav-discuss] [patch] Fix SIGSEGV in dvdnav_describe_title_chapters

[Sylvain HENRY]

My patch checks that cellnr is strictly inferior to endcellnr. It was 
only based on the fact that this condition was true for every case 
except the bogus case (cellnr=0 and endcellnr=0).

If my assumption is wrong, a patch that excludes the case "cellnr=0" 
would do the trick.

Cheers
Sylvain

Le 03/04/2012 20:08, Erik Hovland a écrit :
> On Mon, Apr 2, 2012 at 12:16 PM, Sylvain HENRY<hsyl20 at gmail.com>  wrote:
>> Hi,
>>
>> Please consider checking and applying the attached patch. It fixes a
>> segfault occuring with some DVDs. It seems to be the same problem as the one
>> mentionned here:
>> https://bugs.launchpad.net/ubuntu/+source/libdvdnav/+bug/934471
>>
>> In my case, "cellnr" and "endcellnr" variables were set to 0 when the crash
>> occured.
> Although I don't doubt that your patch fixes the problem for you it seems
> to address a different problem. The crash is likely because:
> cell =&pgc->cell_playback[cellnr-1];
>
> In this case cellnr should never be zero because cellnr-1 will evaluate to
> UINT_MAX. A patch that is more likely to be accepted is one that
> checks cellnr. What does the attached patch do?
>
> E
>