| diff --git a/third_party/libtiff/tif_dirwrite.c b/third_party/libtiff/tif_dirwrite.c |
| index c15a28dbd..ef30c869d 100644 |
| --- a/third_party/libtiff/tif_dirwrite.c |
| +++ b/third_party/libtiff/tif_dirwrite.c |
| @@ -1893,12 +1893,14 @@ TIFFWriteDirectoryTagTransferfunction(TIFF* tif, uint32* ndir, TIFFDirEntry* dir |
| n=3; |
| if (n==3) |
| { |
| - if (!_TIFFmemcmp(tif->tif_dir.td_transferfunction[0],tif->tif_dir.td_transferfunction[2],m*sizeof(uint16))) |
| + if (tif->tif_dir.td_transferfunction[2] == NULL || |
| + !_TIFFmemcmp(tif->tif_dir.td_transferfunction[0],tif->tif_dir.td_transferfunction[2],m*sizeof(uint16))) |
| n=2; |
| } |
| if (n==2) |
| { |
| - if (!_TIFFmemcmp(tif->tif_dir.td_transferfunction[0],tif->tif_dir.td_transferfunction[1],m*sizeof(uint16))) |
| + if (tif->tif_dir.td_transferfunction[1] == NULL || |
| + !_TIFFmemcmp(tif->tif_dir.td_transferfunction[0],tif->tif_dir.td_transferfunction[1],m*sizeof(uint16))) |
| n=1; |
| } |
| if (n==0) |
