contrib/addtiffo/tif_ovrcache.c:50: error: Null Dereference
  pointer `psCache` last assigned on line 49 could be null and is dereferenced at line 50, column 5.

contrib/addtiffo/tif_ovrcache.c:43:1: start of procedure TIFFCreateOvrCache()
41. /************************************************************************/
42. 
43. TIFFOvrCache *TIFFCreateOvrCache( TIFF *hTIFF, toff_t nDirOffset )
    ^
44. 
45. {

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

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* _TIFFcalloc(tmsize_t nmemb, tmsize_t siz)

contrib/addtiffo/tif_ovrcache.c:50:5: 
48. 
49.     psCache = (TIFFOvrCache *) _TIFFmalloc(sizeof(TIFFOvrCache));
50.     psCache->nDirOffset = nDirOffset;
        ^
51.     psCache->hTIFF = hTIFF;
52.     
