bytes in unimportant, unused pieces of index pages) and test failure
because test requires Maria. Compiler warning.
About Valgrind error, two of the three bzero() added here are
needed to silence the error (the third is added for symmetry).


mysql-test/t/maria-gis-rtree.test:
  requires Maria
storage/maria/ma_loghandler.c:
  "uint64->uint16 possible loss of precision" on Windows
storage/maria/ma_rt_index.c:
  We bzero the entire new page, as is done in _ma_enlarge_root()
  for B-tree pages. This silences Valgrind warnings and allows
  better compression.
storage/maria/ma_rt_split.c:
  We bzero the entire new page, as is done in _ma_enlarge_root()
  for B-tree pages. This silences Valgrind warnings and allows
  better compression.