flac: assertion error with fuzzed file

[tholin]

The attached file sometimes cause an assertion error. It's non-deterministic and happens about 30% of the time. Never happens in gdb or valgrind.

$ ffmpeg -i assertion_abort.flac 
ffmpeg version N-69116-g7b32856 Copyright (c) 2000-2015 the FFmpeg developers
  built on Jan 16 2015 21:07:54 with gcc 4.8.3 (Gentoo 4.8.3 p1.1, pie-0.5.9)
  configuration: --prefix=/home/cocobo/repository/mpv-build_vanilla_debug/build_libs --enable-static --disable-shared --enable-gpl --enable-avresample --enable-debug=gdb --disable-doc --disable-optimizations --disable-stripping
  libavutil      54. 17.100 / 54. 17.100
  libavcodec     56. 20.100 / 56. 20.100
  libavformat    56. 19.100 / 56. 19.100
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5.  8.100 /  5.  8.100
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  3.100 / 53.  3.100
Assertion index > -0x20000000 failed at /home/cocobo/repository/mpv-build_vanilla_debug/ffmpeg/libavcodec/parser.c:167
Aborted

[Michael Niedermayer]

Fixed in c4d85fc23c100f7a27d9bad710eb153214868e27