[FFmpeg-cvslog] r9733 - trunk/libavformat/os_support.c

[Michael Niedermayer]

Hi

On Thu, Jul 19, 2007 at 11:39:22AM +0200, Benoit Fouet wrote:
> Michael Niedermayer wrote:
> > Hi
> >
> > On Thu, Jul 19, 2007 at 10:52:38AM +0200, Benoit Fouet wrote:
> >   
> >> Uoti Urpala wrote:
> >>     
> >>> On Thu, 2007-07-19 at 10:17 +0200, Benoit Fouet wrote:
> >>>   
> >>>       
> >>>> M?ns Rullg?rd wrote:
> >>>>     
> >>>>         
> >>>>>>      add1 = atoi(pch);
> >>>>>>      pch = strpbrk(pch,".");
> >>>>>> -    if (pch == 0 || ++pch == 0) return 0;
> >>>>>> +    if (!pch) return 0;
> >>>>>>      add2 = atoi(pch);
> >>>>>>         
> >>>>>>             
> >>>   
> >>>       
> >>>>> This is wrong.  The ++ is needed.  Whoever wrote this code was very
> >>>>> confused.
> >>>>>   
> >>>>>       
> >>>>>           
> >>>> then the right thing to do would be:
> >>>> if(!pch) return 0;
> >>>> addX = atoi(++pch);
> >>>>
> >>>> right ? tome, the check of ++pch is really unneeded
> >>>>     
> >>>>         
> >>> The ++ is needed to move over the '.', but yes check against 0 will
> >>> always be false. The next character of the string (there must be one if
> >>> the string is 0-terminated and the current character is not 0) will not
> >>> be at address 0.
> >>>
> >>> I guess it was meant to be a check against the pointed-to character
> >>> being the terminating 0. However even with that the error checking in
> >>> that function would be really weak - it'll accept addresses such as
> >>> "1.12foo.bar.something.32000.1.1.2" (I think that would be parsed the
> >>> same as "1.12.0.0").
> >>>
> >>>   
> >>>       
> >> so what about using something like
> >> if( sscanf(pch, "%d.%d.%d.%d", &add1, &add2, &add3, &add4) != 4 )
> >>   return 0;
> >>
> >> instead of the strpbrk stuff ?
> >>     
> >
> > fine with me
> >
> > [...]
> >   
> >   
> 
> see attached patch, i also removed the pch definition

ok

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Asymptotically faster algorithms should always be preferred if you have
asymptotical amounts of data
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