TIFFReadScanline(TIFF* tif, void* buf, uint32 row, uint16 sample)
{
	int e;

	if (!TIFFCheckRead(tif, 0))
		return (-1);
	if( (e = TIFFSeek(tif, row, sample)) != 0) {
		/*
		 * Decompress desired row into user buffer.
		 */
		e = (*tif->tif_decoderow)
		    (tif, (uint8*) buf, tif->tif_scanlinesize, sample);  

		/* we are now poised at the beginning of the next row */
		tif->tif_row = row + 1;

		if (e)
			(*tif->tif_postdecode)(tif, (uint8*) buf,
			    tif->tif_scanlinesize);  
	}
	return (e > 0 ? 1 : -1);
}

The product divides a value by zero.