Fixes: signed integer overflow: -3 - 9223372036854775807 cannot be represented in type 'long'
Fixes: 17828/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5645915116797952
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Fixes use of uninitialized memory
Fixes: msan_uninit-mem_7f91f2de7764_2649_PJS_capability_tester.pjs
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>