tools/tiffcrop.c:7162: error: Null Dereference
  pointer `sect_buff` last assigned on line 7157 could be null and is dereferenced by call to `_TIFFmemset()` at line 7162, column 7.

tools/tiffcrop.c:7134:1: start of procedure createImageSection()
7132. 
7133. /* Create a buffer to write one section at a time */
7134. static int
      ^
7135. createImageSection(uint32 sectsize, unsigned char **sect_buff_ptr)
7136.   {

tools/tiffcrop.c:7137:3: 
7135. createImageSection(uint32 sectsize, unsigned char **sect_buff_ptr)
7136.   {
7137.   unsigned  char *sect_buff = NULL;
        ^
7138.   unsigned  char *new_buff  = NULL;
7139.   static    uint32  prev_sectsize = 0;

tools/tiffcrop.c:7138:3: 
7136.   {
7137.   unsigned  char *sect_buff = NULL;
7138.   unsigned  char *new_buff  = NULL;
        ^
7139.   static    uint32  prev_sectsize = 0;
7140.   

tools/tiffcrop.c:7139:3: 
7137.   unsigned  char *sect_buff = NULL;
7138.   unsigned  char *new_buff  = NULL;
7139.   static    uint32  prev_sectsize = 0;
        ^
7140.   
7141.   sect_buff = *sect_buff_ptr;

tools/tiffcrop.c:7141:3: 
7139.   static    uint32  prev_sectsize = 0;
7140.   
7141.   sect_buff = *sect_buff_ptr;
        ^
7142. 
7143.   if (!sect_buff)

tools/tiffcrop.c:7143:8: Taking false branch
7141.   sect_buff = *sect_buff_ptr;
7142. 
7143.   if (!sect_buff)
             ^
7144.     {
7145.     sect_buff = (unsigned char *)_TIFFmalloc(sectsize);

tools/tiffcrop.c:7151:9: Taking true branch
7149.   else
7150.     {
7151.     if (prev_sectsize < sectsize)
              ^
7152.       {
7153.       new_buff = _TIFFrealloc(sect_buff, sectsize);

tools/tiffcrop.c:7153:7: 
7151.     if (prev_sectsize < sectsize)
7152.       {
7153.       new_buff = _TIFFrealloc(sect_buff, sectsize);
            ^
7154.       if (!new_buff)
7155.         {

libtiff/tif_unix.c:265:1: start of procedure _TIFFrealloc()
  263. }
  264. 
  265. void*
       ^
  266. _TIFFrealloc(void* p, tmsize_t s)
  267. {

libtiff/tif_unix.c:268:2: 
  266. _TIFFrealloc(void* p, tmsize_t s)
  267. {
  268. 	return (realloc(p, (size_t) s));
        ^
  269. }
  270. 

libtiff/tif_unix.c:269:1: return from a call to _TIFFrealloc
  267. {
  268. 	return (realloc(p, (size_t) s));
  269. }
       ^
  270. 
  271. void

tools/tiffcrop.c:7154:12: Taking true branch
7152.       {
7153.       new_buff = _TIFFrealloc(sect_buff, sectsize);
7154.       if (!new_buff)
                 ^
7155.         {
7156. 	free (sect_buff);

tools/tiffcrop.c:7156:2: 
7154.       if (!new_buff)
7155.         {
7156. 	free (sect_buff);
       ^
7157.         sect_buff = (unsigned char *)_TIFFmalloc(sectsize);
7158.         }

tools/tiffcrop.c:7157:9: 
7155.         {
7156. 	free (sect_buff);
7157.         sect_buff = (unsigned char *)_TIFFmalloc(sectsize);
              ^
7158.         }
7159.       else

libtiff/tif_unix.c:253:1: start of procedure _TIFFmalloc()
  251. #endif
  252. 
  253. void*
       ^
  254. _TIFFmalloc(tmsize_t s)
  255. {

libtiff/tif_unix.c:256:2: 
  254. _TIFFmalloc(tmsize_t s)
  255. {
  256. 	return (malloc((size_t) s));
        ^
  257. }
  258. 

libtiff/tif_unix.c:257:1: return from a call to _TIFFmalloc
  255. {
  256. 	return (malloc((size_t) s));
  257. }
       ^
  258. 
  259. void

tools/tiffcrop.c:7162:7: 
7160.         sect_buff = new_buff;
7161. 
7162.       _TIFFmemset(sect_buff, 0, sectsize);
            ^
7163.       }
7164.     }

libtiff/tif_unix.c:271:1: start of procedure _TIFFmemset()
  269. }
  270. 
  271. void
       ^
  272. _TIFFmemset(void* p, int v, tmsize_t c)
  273. {

libtiff/tif_unix.c:274:2: 
  272. _TIFFmemset(void* p, int v, tmsize_t c)
  273. {
  274. 	memset(p, v, (size_t) c);
        ^
  275. }
  276. 

libtiff/tif_unix.c:275:1: return from a call to _TIFFmemset
  273. {
  274. 	memset(p, v, (size_t) c);
  275. }
       ^
  276. 
  277. void
