[FFmpeg-cvslog] avcodec/snow: Fix runtime error: signed integer overflow: 1086573993 + 1086573994 cannot be represented in type 'int'

[Michael Niedermayer]

ffmpeg | branch: release/3.3 | Michael Niedermayer <michael at niedermayer.cc> | Sun May 28 17:12:35 2017 +0200| [586e00d7d3ecdc232bbde3e8f4a910a48e3b9eaf] | committer: Michael Niedermayer

avcodec/snow: Fix runtime error: signed integer overflow: 1086573993 + 1086573994 cannot be represented in type 'int'

Fixes: 1871/clusterfuzz-testcase-minimized-5719950331215872

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit b9c032ebc0ad17ac0ffefb915ff96baf9d79cab1)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=586e00d7d3ecdc232bbde3e8f4a910a48e3b9eaf
---

 libavcodec/snow.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavcodec/snow.h b/libavcodec/snow.h
index 59c710b5f9..f7ed1f82e7 100644
--- a/libavcodec/snow.h
+++ b/libavcodec/snow.h
@@ -540,7 +540,8 @@ static inline int get_symbol(RangeCoder *c, uint8_t *state, int is_signed){
     if(get_rac(c, state+0))
         return 0;
     else{
-        int i, e, a;
+        int i, e;
+        unsigned a;
         e= 0;
         while(get_rac(c, state+1 + FFMIN(e,9))){ //1..10
             e++;