mysql-test/r/ndb_basic.result:
  bug#15682 - invalid handling of varchar in position/rnd_pos
mysql-test/t/ndb_basic.test:
  bug#15682 - invalid handling of varchar in position/rnd_pos
ndb/src/kernel/blocks/dbtc/Dbtc.hpp:
  New error code for invalid key
ndb/src/kernel/blocks/dbtc/DbtcMain.cpp:
  Handle invalid key gracefully
ndb/src/kernel/vm/SimulatedBlock.cpp:
  Handle invalid key gracefully
ndb/src/ndbapi/ndberror.c:
  New error code
sql/ha_ndbcluster.cc:
  Fix varchar keys in position/rnd_pos