Andreas Rheinhardt (12023-08-06): > The AVBPrint API guarantees that the string buffer is always > zero-terminated; in order to honour this guarantee, there > obviously must be a string buffer at all and it must have > a size >= 1. Therefore av_bprint_init_for_buffer() treats > passing a NULL buffer or size == 0 as invalid data that > leads to undefined behaviour, namely NPD in case NULL is provided > or a write to a buffer of size 0 in case size == 0. > > But it would be easy to support this, namely by using the internal > buffer with AV_BPRINT_SIZE_COUNT_ONLY in case size == 0. > > There is a reason to allow this: Several functions like > av_channel_(description|name) are actually wrappers > around corresponding AVBPrint functions. They accept user > provided buffers and are supposed to return the required > size of the buffer, which would allow the user to call > it once to get the required buffer size and call it once > more after having allocated the buffer. > If av_bprint_init_for_buffer() treats size == 0 as invalid, > all these users would need to check for this themselves > and basically add the same codeblock that this patch > adds to av_bprint_init_for_buffer(). > > This change is in line with e.g. snprintf() which also allows > the pointer to be NULL in case size is zero. > > This fixes Coverity issues #1503074, #1503076 and #1503082; > all of these issues are about providing NULL to the channel-layout > functions that are wrappers around AVBPrint versions. > > Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com> > --- > Missing lavu minor version bump.
Looks good to me. The other patches in the series too, but I do not maintain the channel layouts. Regards, -- Nicolas George _______________________________________________ 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".
