blob data corrupted by row_merge_write_blob_to_tmp_file()

static dberr_t row_merge_write_blob_to_tmp_file()

dberr_t err= os_file_write(

    IORequestWrite, "(bulk insert)", blob_file->fd,

    field->data, blob_file->offset * srv_page_size, len);

blob_file->offset * srv_page_size

  uint64_t val= blob_file->offset;

  ...

  /* Write offset for next 8 bytes */

  mach_write_to_8(data + 8, val);

blob_file->offset+= field->len;

SET UNIQUE_CHECKS=0;

SET FOREIGN_KEY_CHECKS=0;

/* Required condition: Tuple data size is greater than srv_sort_buf_size */

/* default: innodb_sort_buffer_size = 1048576 */

DROP DATABASE IF EXISTS `debug`;

CREATE DATABASE IF NOT EXISTS `debug`;

USE `debug`;

DROP TABLE IF EXISTS `d1`;

CREATE TABLE `d1` (

  `id` INT NOT NULL AUTO_INCREMENT,

  `data` LONGBLOB NOT NULL,

  PRIMARY KEY (`id`)

) ENGINE=InnoDB;

INSERT INTO `d1` VALUES 

  (DEFAULT, REPEAT('X', @@innodb_sort_buffer_size)),

  (DEFAULT, REPEAT('X', @@innodb_sort_buffer_size))

;

SELECT COUNT(*) AS nb_corrupted_rows FROM debug.d1 WHERE data != REPEAT('X', @@innodb_sort_buffer_size);