if inner routine has more local variables than outer one, and
one of its last variables was used as argument to NOT operator".

THD::spcont was non-0 when we were parsing stored routine/trigger
definition during execution of another stored routine. This confused
methods of Item_splocal and forced them use wrong runtime context.
Fix ensures that we always have THD::spcont equal to zero during
routine/trigger body parsing. This also allows to avoid problems
with errors which occur during parsing and SQL exception handlers.


mysql-test/r/sp.result:
  Test suite for bug#13549.
mysql-test/r/trigger.result:
  Test suite for bug#13549.
mysql-test/t/sp.test:
  Test suite for bug#13549.
mysql-test/t/trigger.test:
  Test suite for bug#13549.
sql/item.cc:
  Protection against using wrong context by SP local variable.
sql/item.h:
  Protection against using wrong context by SP local variable.
sql/protocol.cc:
  An incorrect macro name fixed.
sql/protocol.h:
  An incorrect macro name fixed.
sql/sp.cc:
  Do not allow SP which we are parsing to use other SP
  context (BUG#13549).
sql/sp_head.cc:
  Protection against using wrong context by SP local variable.
sql/sp_rcontext.h:
  Protection against using wrong context by SP local variable.
sql/sql_cache.h:
  An incorrect macro name fixed.
sql/sql_class.cc:
  Protection against using wrong context by SP local variable.
sql/sql_class.h:
  Protection against using wrong context by SP local variable.
sql/sql_trigger.cc:
  Do not allow Trigger which we are parsing to use
  other SP context (BUG#13549).
sql/sql_yacc.yy:
  Protection against using wrong context by SP local variable.