contrib/addtiffo/tif_ovrcache.c:48: error: Null Dereference
  pointer `psCache` last assigned on line 47 could be null and is dereferenced at line 48, column 5.

contrib/addtiffo/tif_ovrcache.c:41:1: start of procedure TIFFCreateOvrCache()
39. /************************************************************************/
40. 
41. TIFFOvrCache *TIFFCreateOvrCache( TIFF *hTIFF, toff_t nDirOffset )
    ^
42. 
43. {

contrib/addtiffo/tif_ovrcache.c:47:5: 
45.     toff_t		nBaseDirOffset;
46. 
47.     psCache = (TIFFOvrCache *) _TIFFmalloc(sizeof(TIFFOvrCache));
        ^
48.     psCache->nDirOffset = nDirOffset;
49.     psCache->hTIFF = hTIFF;

libtiff/tif_unix.c:308:1: start of procedure _TIFFmalloc()
  306. #endif
  307. 
  308. void*
       ^
  309. _TIFFmalloc(tmsize_t s)
  310. {

libtiff/tif_unix.c:311:13: Taking false branch
  309. _TIFFmalloc(tmsize_t s)
  310. {
  311.         if (s == 0)
                   ^
  312.                 return ((void *) NULL);
  313. 

libtiff/tif_unix.c:314:2: 
  312.                 return ((void *) NULL);
  313. 
  314. 	return (malloc((size_t) s));
        ^
  315. }
  316. 

libtiff/tif_unix.c:315:1: return from a call to _TIFFmalloc
  313. 
  314. 	return (malloc((size_t) s));
  315. }
       ^
  316. 
  317. void* _TIFFcalloc(tmsize_t nmemb, tmsize_t siz)

contrib/addtiffo/tif_ovrcache.c:48:5: 
46. 
47.     psCache = (TIFFOvrCache *) _TIFFmalloc(sizeof(TIFFOvrCache));
48.     psCache->nDirOffset = nDirOffset;
        ^
49.     psCache->hTIFF = hTIFF;
50.     
