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: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

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