libavformat/oggparseflac.c:41: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 40 could be null and is dereferenced by call to `get_bits()` at line 41, column 5.

libavformat/oggparseflac.c:28:1: start of procedure flac_header()
26. #define FLAC_STREAMINFO_SIZE 0x22
27. 
28. static int
    ^
29. flac_header (AVFormatContext * s, int idx)
30. {

libavformat/oggparseflac.c:31:5: 
29. flac_header (AVFormatContext * s, int idx)
30. {
31.     ogg_t *ogg = s->priv_data;
        ^
32.     ogg_stream_t *os = ogg->streams + idx;
33.     AVStream *st = s->streams[idx];

libavformat/oggparseflac.c:32:5: 
30. {
31.     ogg_t *ogg = s->priv_data;
32.     ogg_stream_t *os = ogg->streams + idx;
        ^
33.     AVStream *st = s->streams[idx];
34.     GetBitContext gb;

libavformat/oggparseflac.c:33:5: 
31.     ogg_t *ogg = s->priv_data;
32.     ogg_stream_t *os = ogg->streams + idx;
33.     AVStream *st = s->streams[idx];
        ^
34.     GetBitContext gb;
35.     int mdt;

libavformat/oggparseflac.c:37:9: Taking false branch
35.     int mdt;
36. 
37.     if (os->buf[os->pstart] == 0xff)
            ^
38.         return 0;
39. 

libavformat/oggparseflac.c:40:5: 
38.         return 0;
39. 
40.     init_get_bits(&gb, os->buf + os->pstart, os->psize*8);
        ^
41.     get_bits(&gb, 1); /* metadata_last */
42.     mdt = get_bits(&gb, 7);

libavcodec/bitstream.h:758:1: start of procedure init_get_bits()
  756.  * @param bit_size the size of the buffer in bits
  757.  */
  758. static inline void init_get_bits(GetBitContext *s,
       ^
  759.                    const uint8_t *buffer, int bit_size)
  760. {

libavcodec/bitstream.h:761:5: 
  759.                    const uint8_t *buffer, int bit_size)
  760. {
  761.     int buffer_size= (bit_size+7)>>3;
           ^
  762.     if(buffer_size < 0 || bit_size < 0) {
  763.         buffer_size = bit_size = 0;

libavcodec/bitstream.h:762:8: Taking true branch
  760. {
  761.     int buffer_size= (bit_size+7)>>3;
  762.     if(buffer_size < 0 || bit_size < 0) {
              ^
  763.         buffer_size = bit_size = 0;
  764.         buffer = NULL;

libavcodec/bitstream.h:763:9: 
  761.     int buffer_size= (bit_size+7)>>3;
  762.     if(buffer_size < 0 || bit_size < 0) {
  763.         buffer_size = bit_size = 0;
               ^
  764.         buffer = NULL;
  765.     }

libavcodec/bitstream.h:764:9: 
  762.     if(buffer_size < 0 || bit_size < 0) {
  763.         buffer_size = bit_size = 0;
  764.         buffer = NULL;
               ^
  765.     }
  766. 

libavcodec/bitstream.h:767:5: 
  765.     }
  766. 
  767.     s->buffer= buffer;
           ^
  768.     s->size_in_bits= bit_size;
  769.     s->buffer_end= buffer + buffer_size;

libavcodec/bitstream.h:768:5: 
  766. 
  767.     s->buffer= buffer;
  768.     s->size_in_bits= bit_size;
           ^
  769.     s->buffer_end= buffer + buffer_size;
  770. #ifdef ALT_BITSTREAM_READER

libavcodec/bitstream.h:769:5: 
  767.     s->buffer= buffer;
  768.     s->size_in_bits= bit_size;
  769.     s->buffer_end= buffer + buffer_size;
           ^
  770. #ifdef ALT_BITSTREAM_READER
  771.     s->index=0;

libavcodec/bitstream.h:771:5: 
  769.     s->buffer_end= buffer + buffer_size;
  770. #ifdef ALT_BITSTREAM_READER
  771.     s->index=0;
           ^
  772. #elif defined LIBMPEG2_BITSTREAM_READER
  773.     s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1));

libavcodec/bitstream.h:781:1: return from a call to init_get_bits
  779.     skip_bits_long(s, 0);
  780. #endif
  781. }
       ^
  782. 
  783. static inline void align_get_bits(GetBitContext *s)

libavformat/oggparseflac.c:41:5: 
39. 
40.     init_get_bits(&gb, os->buf + os->pstart, os->psize*8);
41.     get_bits(&gb, 1); /* metadata_last */
        ^
42.     mdt = get_bits(&gb, 7);
43. 

libavcodec/bitstream.h:655:1: start of procedure get_bits()
  653.  * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
  654.  */
  655. static inline unsigned int get_bits(GetBitContext *s, int n){
       ^
  656.     register int tmp;
  657.     OPEN_READER(re, s)

libavcodec/bitstream.h:657:5: 
  655. static inline unsigned int get_bits(GetBitContext *s, int n){
  656.     register int tmp;
  657.     OPEN_READER(re, s)
           ^
  658.     UPDATE_CACHE(re, s)
  659.     tmp= SHOW_UBITS(re, s, n);

libavcodec/bitstream.h:658:5: 
  656.     register int tmp;
  657.     OPEN_READER(re, s)
  658.     UPDATE_CACHE(re, s)
           ^
  659.     tmp= SHOW_UBITS(re, s, n);
  660.     LAST_SKIP_BITS(re, s, n)
