record in table)

key_restore function didn't work as intended in the case of
VARCHAR or BLOB fields, stored the restored key in field->ptr instead
of to_record.
That produced the wrong key so search returned wrong result


mysql-test/r/partition.result:
  result added
mysql-test/t/partition.test:
  testcase
sql/field.cc:
  Field_blob::store_length made static
sql/field.h:
  Field_blob::store_length and set_ptr functions implemented in slightly
  different way
sql/ha_ndbcluster.cc:
  set_ptr_offset used
sql/key.cc:
  set key_part->field->ptr to the proper place inside the to_record
  so the restored key will be placed there as key_restore
  is supposed to behave