libavcodec/xan.c:115: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 112 could be null and is dereferenced by call to `get_bits1()` at line 115, column 37.

libavcodec/xan.c:97:1: start of procedure xan_huffman_decode()
95. }
96. 
97. static int xan_huffman_decode(unsigned char *dest, int dest_len,
    ^
98.                               const unsigned char *src, int src_len)
99. {

libavcodec/xan.c:100:5: 
 98.                               const unsigned char *src, int src_len)
 99. {
100.     unsigned char byte = *src++;
         ^
101.     unsigned char ival = byte + 0x16;
102.     const unsigned char * ptr = src + byte*2;

libavcodec/xan.c:101:5: 
 99. {
100.     unsigned char byte = *src++;
101.     unsigned char ival = byte + 0x16;
         ^
102.     const unsigned char * ptr = src + byte*2;
103.     int ptr_len = src_len - 1 - byte*2;

libavcodec/xan.c:102:5: 
100.     unsigned char byte = *src++;
101.     unsigned char ival = byte + 0x16;
102.     const unsigned char * ptr = src + byte*2;
         ^
103.     int ptr_len = src_len - 1 - byte*2;
104.     unsigned char val = ival;

libavcodec/xan.c:103:5: 
101.     unsigned char ival = byte + 0x16;
102.     const unsigned char * ptr = src + byte*2;
103.     int ptr_len = src_len - 1 - byte*2;
         ^
104.     unsigned char val = ival;
105.     unsigned char *dest_end = dest + dest_len;

libavcodec/xan.c:104:5: 
102.     const unsigned char * ptr = src + byte*2;
103.     int ptr_len = src_len - 1 - byte*2;
104.     unsigned char val = ival;
         ^
105.     unsigned char *dest_end = dest + dest_len;
106.     unsigned char *dest_start = dest;

libavcodec/xan.c:105:5: 
103.     int ptr_len = src_len - 1 - byte*2;
104.     unsigned char val = ival;
105.     unsigned char *dest_end = dest + dest_len;
         ^
106.     unsigned char *dest_start = dest;
107.     GetBitContext gb;

libavcodec/xan.c:106:5: 
104.     unsigned char val = ival;
105.     unsigned char *dest_end = dest + dest_len;
106.     unsigned char *dest_start = dest;
         ^
107.     GetBitContext gb;
108. 

libavcodec/xan.c:109:9: Taking false branch
107.     GetBitContext gb;
108. 
109.     if (ptr_len < 0)
             ^
110.         return AVERROR_INVALIDDATA;
111. 

libavcodec/xan.c:112:5: 
110.         return AVERROR_INVALIDDATA;
111. 
112.     init_get_bits(&gb, ptr, ptr_len * 8);
         ^
113. 
114.     while (val != 0x16) {

libavcodec/get_bits.h:375:1: start of procedure init_get_bits()
  373.  * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
  374.  */
  375. static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer,
       ^
  376.                                 int bit_size)
  377. {

libavcodec/get_bits.h:379:5: 
  377. {
  378.     int buffer_size;
  379.     int ret = 0;
           ^
  380. 
  381.     if (bit_size > INT_MAX - 7 || bit_size < 0 || !buffer) {

libavcodec/get_bits.h:381:9: Taking true branch
  379.     int ret = 0;
  380. 
  381.     if (bit_size > INT_MAX - 7 || bit_size < 0 || !buffer) {
               ^
  382.         buffer_size = bit_size = 0;
  383.         buffer      = NULL;

libavcodec/get_bits.h:382:9: 
  380. 
  381.     if (bit_size > INT_MAX - 7 || bit_size < 0 || !buffer) {
  382.         buffer_size = bit_size = 0;
               ^
  383.         buffer      = NULL;
  384.         ret         = AVERROR_INVALIDDATA;

libavcodec/get_bits.h:383:9: 
  381.     if (bit_size > INT_MAX - 7 || bit_size < 0 || !buffer) {
  382.         buffer_size = bit_size = 0;
  383.         buffer      = NULL;
               ^
  384.         ret         = AVERROR_INVALIDDATA;
  385.     }

libavcodec/get_bits.h:384:9: 
  382.         buffer_size = bit_size = 0;
  383.         buffer      = NULL;
  384.         ret         = AVERROR_INVALIDDATA;
               ^
  385.     }
  386. 

libavcodec/get_bits.h:387:5: 
  385.     }
  386. 
  387.     buffer_size = (bit_size + 7) >> 3;
           ^
  388. 
  389.     s->buffer             = buffer;

libavcodec/get_bits.h:389:5: 
  387.     buffer_size = (bit_size + 7) >> 3;
  388. 
  389.     s->buffer             = buffer;
           ^
  390.     s->size_in_bits       = bit_size;
  391. #if !UNCHECKED_BITSTREAM_READER

libavcodec/get_bits.h:390:5: 
  388. 
  389.     s->buffer             = buffer;
  390.     s->size_in_bits       = bit_size;
           ^
  391. #if !UNCHECKED_BITSTREAM_READER
  392.     s->size_in_bits_plus8 = bit_size + 8;

libavcodec/get_bits.h:392:5: 
  390.     s->size_in_bits       = bit_size;
  391. #if !UNCHECKED_BITSTREAM_READER
  392.     s->size_in_bits_plus8 = bit_size + 8;
           ^
  393. #endif
  394.     s->buffer_end         = buffer + buffer_size;

libavcodec/get_bits.h:394:5: 
  392.     s->size_in_bits_plus8 = bit_size + 8;
  393. #endif
  394.     s->buffer_end         = buffer + buffer_size;
           ^
  395.     s->index              = 0;
  396. 

libavcodec/get_bits.h:395:5: 
  393. #endif
  394.     s->buffer_end         = buffer + buffer_size;
  395.     s->index              = 0;
           ^
  396. 
  397.     return ret;

libavcodec/get_bits.h:397:5: 
  395.     s->index              = 0;
  396. 
  397.     return ret;
           ^
  398. }
  399. 

libavcodec/get_bits.h:398:1: return from a call to init_get_bits
  396. 
  397.     return ret;
  398. }
       ^
  399. 
  400. /**

libavcodec/xan.c:114:12: Loop condition is true. Entering loop body
112.     init_get_bits(&gb, ptr, ptr_len * 8);
113. 
114.     while (val != 0x16) {
                ^
115.         unsigned idx = val - 0x17 + get_bits1(&gb) * byte;
116.         if (idx >= 2 * byte)

libavcodec/xan.c:115:9: 
113. 
114.     while (val != 0x16) {
115.         unsigned idx = val - 0x17 + get_bits1(&gb) * byte;
             ^
116.         if (idx >= 2 * byte)
117.             return AVERROR_INVALIDDATA;

libavcodec/get_bits.h:271:1: start of procedure get_bits1()
  269. }
  270. 
  271. static inline unsigned int get_bits1(GetBitContext *s)
       ^
  272. {
  273.     unsigned int index = s->index;

libavcodec/get_bits.h:273:5: 
  271. static inline unsigned int get_bits1(GetBitContext *s)
  272. {
  273.     unsigned int index = s->index;
           ^
  274.     uint8_t result     = s->buffer[index >> 3];
  275. #ifdef BITSTREAM_READER_LE

libavcodec/get_bits.h:274:5: 
  272. {
  273.     unsigned int index = s->index;
  274.     uint8_t result     = s->buffer[index >> 3];
           ^
  275. #ifdef BITSTREAM_READER_LE
  276.     result >>= index & 7;
