avcodec/get_bits: Fix get_sbits_long(0)

Fixes undefined behavior
Fixes: 640889-media

Found-by: Matt Wolenetz <wolenetz@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit c72fa43234)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2016-12-03 23:44:56 +01:00
parent a9479bbc57
commit 2e7800778c
1 changed files with 4 additions and 0 deletions

View File

@ -374,6 +374,10 @@ static inline uint64_t get_bits64(GetBitContext *s, int n)
*/
static inline int get_sbits_long(GetBitContext *s, int n)
{
// sign_extend(x, 0) is undefined
if (!n)
return 0;
return sign_extend(get_bits_long(s, n), n);
}