row0mysql.c:

	byte*	dest,		/* in: where to store */

	ulint	col_len,	/* in: dest buffer size: determines into

				how many bytes the BLOB length is stored,

				this may vary from 1 to 4 bytes */

	byte*	data,		/* in: BLOB data */

	ulint	len)		/* in: BLOB length */

				the space for the length may vary from 1

				to 4 bytes */

	byte*	data,		/* in: BLOB data; if the value to store

				is SQL NULL this should be NULL pointer */

	ulint	len)		/* in: BLOB length; if the value to store

				is SQL NULL this should be 0; remember

				also to set the NULL bit in the MySQL record

				header! */

{

	ulint	sum	= 0;

	ulint	i;

	/* MySQL might assume the field is set to zero except the length and

	the pointer fields */

	memset(dest, '\0', col_len);

	/* In dest there are 1 - 4 bytes reserved for the BLOB length,

	and after that 8 bytes reserved for the pointer to the data.

	In 32-bit architectures we only use the first 4 bytes of the pointer