On Sun, Aug 02, 2020 at 08:40:27PM +0100, Jack Haughton wrote: > Hello, > > Apologies for the delay in replying. This patch is not to address a > specific problem that currently exists, but rather to restore the > robustness to invalid input that previously existed in this function. The > motivation for the patch is that we would like to merge a500b975 into our > local tree to gain support for gcc 10, but there are concerns about the > removal of the null check. av_parse_video_rate() passes its argument > directly to strcmp, which would cause undefined behaviour if the argument > was NULL.
now it makes it even less sense to me. av_parse_video_rate() doesnt support a NULL argument before or after your patch, its undefined behaviour either way. what you change is a private function using that public function. Now if you changed the public function to do something specific with a NULL argument then that would be more robust maybe but not when its done to a single caller which should not pass NULL there thx > > Thanks, > Jack > > On Fri, Jul 31, 2020 at 8:31 PM Michael Niedermayer <mich...@niedermayer.cc> > wrote: > > > Hi > > > > On Fri, Jul 31, 2020 at 03:53:56PM +0100, Jack Haughton wrote: > > > Commit a500b975 removed NULL input handling from this function, > > > moving the check higher up the call tree in one branch. However, > > > there is another call to set_string_video_rate() which may pass > > > NULL, and future users of the function may not be clear that > > > a NULL check is required. This patch restores the NULL check to > > > avoid these problems. > > > > Does this affect something else than the seting based on defaults ? > > because the defaults should probably be valid values > > or if you disagree, iam curious where the default would be intentionally > > invalid > > > > thx > > > > [...] > > -- > > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > > > Breaking DRM is a little like attempting to break through a door even > > though the window is wide open and the only thing in the house is a bunch > > of things you dont want and which you would get tomorrow for free anyway > > > > > -- > > Argon Design Ltd., Registration No. 06977690, a Broadcom Inc. company > > Registered in England with registered office at St John's Innovation > Centre, Cowley Road, Cambridge, CB4 0WS > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB It is what and why we do it that matters, not just one of them.
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