Division by zero resulting in a crash in Block::Block

[GoogleCodeExporter]

Reproducing samples: 32streams.mkv.6fc.4, dv420_misdetected_as_411.mkv.6fc.40, 
matroska_h264_vorbis_0x0000_sws10_screenshot_failure.mkv.6fc.68

The samples can be found at http://j00ru.vexillium.org/dump/libwebm/

Program received signal SIGFPE, Arithmetic exception.
0x000000000041ab1a in Block () at libwebm/mkvparser.cpp:8535
8535         assert((total_size % m_frame_count) == 0);
(gdb) l
8530         assert(pos == stop);
8531     }
8532     else if (lacing == 2)  //fixed-size lacing
8533     {
8534         const long long total_size = stop - pos;
8535         assert((total_size % m_frame_count) == 0);
8536
8537         const long long frame_size = total_size / m_frame_count;
8538         assert(frame_size <= LONG_MAX);
8539
(gdb) where
#0  0x000000000041ab1a in Block () at libwebm/mkvparser.cpp:8535
#1  0x000000000041a31b in BlockGroup () at libwebm/mkvparser.cpp:8345
#2  0x0000000000419356 in CreateBlockGroup () at libwebm/mkvparser.cpp:7772
#3  0x0000000000418e0a in CreateBlock () at libwebm/mkvparser.cpp:7675
#4  0x0000000000417b47 in ParseBlockGroup () at libwebm/mkvparser.cpp:7136
#5  0x0000000000416c2c in Parse () at libwebm/mkvparser.cpp:6771
#6  0x000000000041983e in GetNext () at libwebm/mkvparser.cpp:7883
#7  0x00000000004074e7 in main (argc=2, argv=0x7fffffffe2b8) at 
libwebm/sample.cpp:284

Original issue reported on code.google.com by mjurc...@google.com on 24 Feb 2012 at 1:08

[GoogleCodeExporter]

This might be fixed by Matt last CL

Original comment by albe...@google.com on 1 Mar 2012 at 7:07

• Changed state: Started
• Added labels: Mstone-10

[GoogleCodeExporter]

Original comment by matthewj...@google.com on 14 Mar 2012 at 11:59

• Changed state: Fixed