libavcodec/smacker.c:289: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 287 could be null and is dereferenced by call to `get_bits1()` at line 289, column 9.

libavcodec/smacker.c:278:1: start of procedure decode_header_trees()
276. }
277. 
278. static int decode_header_trees(SmackVContext *smk) {
     ^
279.     GetBitContext gb;
280.     int mmap_size, mclr_size, full_size, type_size;

libavcodec/smacker.c:282:5: 
280.     int mmap_size, mclr_size, full_size, type_size;
281. 
282.     mmap_size = AV_RL32(smk->avctx->extradata);
         ^
283.     mclr_size = AV_RL32(smk->avctx->extradata + 4);
284.     full_size = AV_RL32(smk->avctx->extradata + 8);

libavcodec/smacker.c:283:5: 
281. 
282.     mmap_size = AV_RL32(smk->avctx->extradata);
283.     mclr_size = AV_RL32(smk->avctx->extradata + 4);
         ^
284.     full_size = AV_RL32(smk->avctx->extradata + 8);
285.     type_size = AV_RL32(smk->avctx->extradata + 12);

libavcodec/smacker.c:284:5: 
282.     mmap_size = AV_RL32(smk->avctx->extradata);
283.     mclr_size = AV_RL32(smk->avctx->extradata + 4);
284.     full_size = AV_RL32(smk->avctx->extradata + 8);
         ^
285.     type_size = AV_RL32(smk->avctx->extradata + 12);
286. 

libavcodec/smacker.c:285:5: 
283.     mclr_size = AV_RL32(smk->avctx->extradata + 4);
284.     full_size = AV_RL32(smk->avctx->extradata + 8);
285.     type_size = AV_RL32(smk->avctx->extradata + 12);
         ^
286. 
287.     init_get_bits(&gb, smk->avctx->extradata + 16, (smk->avctx->extradata_size - 16) * 8);

libavcodec/smacker.c:287:5: 
285.     type_size = AV_RL32(smk->avctx->extradata + 12);
286. 
287.     init_get_bits(&gb, smk->avctx->extradata + 16, (smk->avctx->extradata_size - 16) * 8);
         ^
288. 
289.     if(!get_bits1(&gb)) {

libavcodec/get_bits.h:383:1: start of procedure init_get_bits()
  381.  * responsible for checking for the buffer end yourself (take advantage of the padding)!
  382.  */
  383. static inline void init_get_bits(GetBitContext *s,
       ^
  384.                    const uint8_t *buffer, int bit_size)
  385. {

libavcodec/get_bits.h:386:5: 
  384.                    const uint8_t *buffer, int bit_size)
  385. {
  386.     int buffer_size = (bit_size+7)>>3;
           ^
  387.     if (buffer_size < 0 || bit_size < 0) {
  388.         buffer_size = bit_size = 0;

libavcodec/get_bits.h:387:9: Taking true branch
  385. {
  386.     int buffer_size = (bit_size+7)>>3;
  387.     if (buffer_size < 0 || bit_size < 0) {
               ^
  388.         buffer_size = bit_size = 0;
  389.         buffer = NULL;

libavcodec/get_bits.h:388:9: 
  386.     int buffer_size = (bit_size+7)>>3;
  387.     if (buffer_size < 0 || bit_size < 0) {
  388.         buffer_size = bit_size = 0;
               ^
  389.         buffer = NULL;
  390.     }

libavcodec/get_bits.h:389:9: 
  387.     if (buffer_size < 0 || bit_size < 0) {
  388.         buffer_size = bit_size = 0;
  389.         buffer = NULL;
               ^
  390.     }
  391. 

libavcodec/get_bits.h:392:5: 
  390.     }
  391. 
  392.     s->buffer       = buffer;
           ^
  393.     s->size_in_bits = bit_size;
  394.     s->buffer_end   = buffer + buffer_size;

libavcodec/get_bits.h:393:5: 
  391. 
  392.     s->buffer       = buffer;
  393.     s->size_in_bits = bit_size;
           ^
  394.     s->buffer_end   = buffer + buffer_size;
  395. #ifdef ALT_BITSTREAM_READER

libavcodec/get_bits.h:394:5: 
  392.     s->buffer       = buffer;
  393.     s->size_in_bits = bit_size;
  394.     s->buffer_end   = buffer + buffer_size;
           ^
  395. #ifdef ALT_BITSTREAM_READER
  396.     s->index        = 0;

libavcodec/get_bits.h:396:5: 
  394.     s->buffer_end   = buffer + buffer_size;
  395. #ifdef ALT_BITSTREAM_READER
  396.     s->index        = 0;
           ^
  397. #elif defined A32_BITSTREAM_READER
  398.     s->buffer_ptr   = (uint32_t*)((intptr_t)buffer & ~3);

libavcodec/get_bits.h:402:1: return from a call to init_get_bits
  400.     skip_bits_long(s, 0);
  401. #endif
  402. }
       ^
  403. 
  404. static inline void align_get_bits(GetBitContext *s)

libavcodec/smacker.c:289:9: 
287.     init_get_bits(&gb, smk->avctx->extradata + 16, (smk->avctx->extradata_size - 16) * 8);
288. 
289.     if(!get_bits1(&gb)) {
             ^
290.         av_log(smk->avctx, AV_LOG_INFO, "Skipping MMAP tree\n");
291.         smk->mmap_tbl = av_malloc(sizeof(int) * 2);

libavcodec/get_bits.h:303:1: start of procedure get_bits1()
  301. }
  302. 
  303. static inline unsigned int get_bits1(GetBitContext *s){
       ^
  304. #ifdef ALT_BITSTREAM_READER
  305.     unsigned int index = s->index;

libavcodec/get_bits.h:305:5: 
  303. static inline unsigned int get_bits1(GetBitContext *s){
  304. #ifdef ALT_BITSTREAM_READER
  305.     unsigned int index = s->index;
           ^
  306.     uint8_t result = s->buffer[index>>3];
  307. #ifdef ALT_BITSTREAM_READER_LE

libavcodec/get_bits.h:306:5: 
  304. #ifdef ALT_BITSTREAM_READER
  305.     unsigned int index = s->index;
  306.     uint8_t result = s->buffer[index>>3];
           ^
  307. #ifdef ALT_BITSTREAM_READER_LE
  308.     result >>= index & 7;
