tools/tiffcrop.c:7200: error: Null Dereference
  pointer `sect_buff` last assigned on line 7198 could be null and is dereferenced by call to `_TIFFmemset()` at line 7200, column 5.

tools/tiffcrop.c:7187:1: start of procedure createImageSection()
7185. 
7186. /* Create a buffer to write one section at a time */
7187. static int
      ^
7188. createImageSection(uint32 sectsize, unsigned char **sect_buff_ptr)
7189.   {

tools/tiffcrop.c:7190:3: 
7188. createImageSection(uint32 sectsize, unsigned char **sect_buff_ptr)
7189.   {
7190.   unsigned  char *sect_buff = NULL;
        ^
7191.   unsigned  char *new_buff  = NULL;
7192.   static    uint32  prev_sectsize = 0;

tools/tiffcrop.c:7191:3: 
7189.   {
7190.   unsigned  char *sect_buff = NULL;
7191.   unsigned  char *new_buff  = NULL;
        ^
7192.   static    uint32  prev_sectsize = 0;
7193.   

tools/tiffcrop.c:7192:3: 
7190.   unsigned  char *sect_buff = NULL;
7191.   unsigned  char *new_buff  = NULL;
7192.   static    uint32  prev_sectsize = 0;
        ^
7193.   
7194.   sect_buff = *sect_buff_ptr;

tools/tiffcrop.c:7194:3: 
7192.   static    uint32  prev_sectsize = 0;
7193.   
7194.   sect_buff = *sect_buff_ptr;
        ^
7195. 
7196.   if (!sect_buff)

tools/tiffcrop.c:7196:8: Taking true branch
7194.   sect_buff = *sect_buff_ptr;
7195. 
7196.   if (!sect_buff)
             ^
7197.     {
7198.     sect_buff = (unsigned char *)_TIFFmalloc(sectsize);

tools/tiffcrop.c:7198:5: 
7196.   if (!sect_buff)
7197.     {
7198.     sect_buff = (unsigned char *)_TIFFmalloc(sectsize);
          ^
7199.     *sect_buff_ptr = sect_buff;
7200.     _TIFFmemset(sect_buff, 0, sectsize);

libtiff/tif_unix.c:257:1: start of procedure _TIFFmalloc()
  255. #endif
  256. 
  257. void*
       ^
  258. _TIFFmalloc(tmsize_t s)
  259. {

libtiff/tif_unix.c:260:13: Taking false branch
  258. _TIFFmalloc(tmsize_t s)
  259. {
  260.         if (s == 0)
                   ^
  261.                 return ((void *) NULL);
  262. 

libtiff/tif_unix.c:263:2: 
  261.                 return ((void *) NULL);
  262. 
  263. 	return (malloc((size_t) s));
        ^
  264. }
  265. 

libtiff/tif_unix.c:264:1: return from a call to _TIFFmalloc
  262. 
  263. 	return (malloc((size_t) s));
  264. }
       ^
  265. 
  266. void

tools/tiffcrop.c:7199:5: 
7197.     {
7198.     sect_buff = (unsigned char *)_TIFFmalloc(sectsize);
7199.     *sect_buff_ptr = sect_buff;
          ^
7200.     _TIFFmemset(sect_buff, 0, sectsize);
7201.     }

tools/tiffcrop.c:7200:5: 
7198.     sect_buff = (unsigned char *)_TIFFmalloc(sectsize);
7199.     *sect_buff_ptr = sect_buff;
7200.     _TIFFmemset(sect_buff, 0, sectsize);
          ^
7201.     }
7202.   else

libtiff/tif_unix.c:278:1: start of procedure _TIFFmemset()
  276. }
  277. 
  278. void
       ^
  279. _TIFFmemset(void* p, int v, tmsize_t c)
  280. {

libtiff/tif_unix.c:281:2: 
  279. _TIFFmemset(void* p, int v, tmsize_t c)
  280. {
  281. 	memset(p, v, (size_t) c);
        ^
  282. }
  283. 

libtiff/tif_unix.c:282:1: return from a call to _TIFFmemset
  280. {
  281. 	memset(p, v, (size_t) c);
  282. }
       ^
  283. 
  284. void
