It was syntactically correct to define 
 spatial keys over parts of columns (e.g.
 ALTER TABLE t1 ADD x GEOMETRY NOT NULL, 
   ADD SPATIAL KEY (x(32))).
 This may lead to undefined results and/or
 interpretation.
 Fixed by not allowing partial column 
 specification in a SPATIAL index definition.


mysql-test/r/alter_table.result:
  Bug #26794: 5.1 part
   test case
mysql-test/r/gis-rtree.result:
  Bug #26794: 5.1 part
   updated the tests to the new syntax
mysql-test/t/alter_table.test:
  Bug #26794: 5.1 part
   test case
mysql-test/t/gis-rtree.test:
  Bug #26794: 5.1 part
   updated the tests to the new syntax
sql/sql_table.cc:
  Bug #26794: 5.1 part
   Disable defining SPATIAL KEYS with sub-key parts