tools/tiffcrop.c:7350: error: Null Dereference
  pointer `sect_buff` last assigned on line 7345 could be null and is dereferenced by call to `_TIFFmemset()` at line 7350, column 7.

tools/tiffcrop.c:7322:1: start of procedure createImageSection()
7320. 
7321. /* Create a buffer to write one section at a time */
7322. static int
      ^
7323. createImageSection(uint32 sectsize, unsigned char **sect_buff_ptr)
7324.   {

tools/tiffcrop.c:7325:3: 
7323. createImageSection(uint32 sectsize, unsigned char **sect_buff_ptr)
7324.   {
7325.   unsigned  char *sect_buff = NULL;
        ^
7326.   unsigned  char *new_buff  = NULL;
7327.   static    uint32  prev_sectsize = 0;

tools/tiffcrop.c:7326:3: 
7324.   {
7325.   unsigned  char *sect_buff = NULL;
7326.   unsigned  char *new_buff  = NULL;
        ^
7327.   static    uint32  prev_sectsize = 0;
7328.   

tools/tiffcrop.c:7327:3: 
7325.   unsigned  char *sect_buff = NULL;
7326.   unsigned  char *new_buff  = NULL;
7327.   static    uint32  prev_sectsize = 0;
        ^
7328.   
7329.   sect_buff = *sect_buff_ptr;

tools/tiffcrop.c:7329:3: 
7327.   static    uint32  prev_sectsize = 0;
7328.   
7329.   sect_buff = *sect_buff_ptr;
        ^
7330. 
7331.   if (!sect_buff)

tools/tiffcrop.c:7331:8: Taking false branch
7329.   sect_buff = *sect_buff_ptr;
7330. 
7331.   if (!sect_buff)
             ^
7332.     {
7333.     sect_buff = (unsigned char *)_TIFFmalloc(sectsize);

tools/tiffcrop.c:7339:9: Taking true branch
7337.   else
7338.     {
7339.     if (prev_sectsize < sectsize)
              ^
7340.       {
7341.       new_buff = _TIFFrealloc(sect_buff, sectsize);

tools/tiffcrop.c:7341:7: 
7339.     if (prev_sectsize < sectsize)
7340.       {
7341.       new_buff = _TIFFrealloc(sect_buff, sectsize);
            ^
7342.       if (!new_buff)
7343.         {

libtiff/tif_unix.c:325:1: start of procedure _TIFFrealloc()
  323. }
  324. 
  325. void*
       ^
  326. _TIFFrealloc(void* p, tmsize_t s)
  327. {

libtiff/tif_unix.c:328:2: 
  326. _TIFFrealloc(void* p, tmsize_t s)
  327. {
  328. 	return (realloc(p, (size_t) s));
        ^
  329. }
  330. 

libtiff/tif_unix.c:329:1: return from a call to _TIFFrealloc
  327. {
  328. 	return (realloc(p, (size_t) s));
  329. }
       ^
  330. 
  331. void

tools/tiffcrop.c:7342:12: Taking true branch
7340.       {
7341.       new_buff = _TIFFrealloc(sect_buff, sectsize);
7342.       if (!new_buff)
                 ^
7343.         {
7344. 	free (sect_buff);

tools/tiffcrop.c:7344:2: 
7342.       if (!new_buff)
7343.         {
7344. 	free (sect_buff);
       ^
7345.         sect_buff = (unsigned char *)_TIFFmalloc(sectsize);
7346.         }

tools/tiffcrop.c:7345:9: 
7343.         {
7344. 	free (sect_buff);
7345.         sect_buff = (unsigned char *)_TIFFmalloc(sectsize);
              ^
7346.         }
7347.       else

libtiff/tif_unix.c:310:1: start of procedure _TIFFmalloc()
  308. #endif
  309. 
  310. void*
       ^
  311. _TIFFmalloc(tmsize_t s)
  312. {

libtiff/tif_unix.c:313:13: Taking false branch
  311. _TIFFmalloc(tmsize_t s)
  312. {
  313.         if (s == 0)
                   ^
  314.                 return ((void *) NULL);
  315. 

libtiff/tif_unix.c:316:2: 
  314.                 return ((void *) NULL);
  315. 
  316. 	return (malloc((size_t) s));
        ^
  317. }
  318. 

libtiff/tif_unix.c:317:1: return from a call to _TIFFmalloc
  315. 
  316. 	return (malloc((size_t) s));
  317. }
       ^
  318. 
  319. void

tools/tiffcrop.c:7350:7: 
7348.         sect_buff = new_buff;
7349. 
7350.       _TIFFmemset(sect_buff, 0, sectsize);
            ^
7351.       }
7352.     }

libtiff/tif_unix.c:331:1: start of procedure _TIFFmemset()
  329. }
  330. 
  331. void
       ^
  332. _TIFFmemset(void* p, int v, tmsize_t c)
  333. {

libtiff/tif_unix.c:334:2: 
  332. _TIFFmemset(void* p, int v, tmsize_t c)
  333. {
  334. 	memset(p, v, (size_t) c);
        ^
  335. }
  336. 

libtiff/tif_unix.c:335:1: return from a call to _TIFFmemset
  333. {
  334. 	memset(p, v, (size_t) c);
  335. }
       ^
  336. 
  337. void
