This bug is a side-effect of bug fix #16377. NOW() is optimized in
BETWEEN to integer constants to speed up query execution. When view is being
created it saves already modified query and thus becomes wrong.

The agg_cmp_type() function now substitutes constant result DATE/TIME functions 
for their results only if the current query isn't CREATE VIEW or SHOW CREATE
VIEW.


mysql-test/t/view.test:
  Added a test case for bug#15950: NOW() optimized away in VIEWs
mysql-test/r/view.result:
  Added a test case for bug#15950: NOW() optimized away in VIEWs
sql/item_cmpfunc.cc:
  Fixed bug#15950: NOW() optimized away in VIEWs
  The agg_cmp_type() function now substitutes constant result DATE/TIME functions 
  for their results only if the current query isn't CREATE VIEW or SHOW CREATE
  VIEW.