Fixed bug #25580: incorrect stored representations of views in cases

when they contain the '!' operator.
Added an implementation for the method Item_func_not::print. 
The method encloses any NOT expression into extra parentheses to avoid
incorrect stored representations of views that use the '!' operators.
Without this change when a view was created that contained
the expression !0*5  its stored representation contained not this
expression but rather the expression not(0)*5 . 
The operator '!' is of a higher precedence than '*', while NOT is 
of a lower precedence than '*'. That's why the expression !0*5 
is interpreted as not(0)*5, while the expression not(0)*5 is interpreted
as not((0)*5) unless sql_mode is set to HIGH_NOT_PRECEDENCE.
Now we translate !0*5 into (not(0))*5. 

1 files changed, 1 insertions, 0 deletions

diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index 1d85d08c434..54457d37d18 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -269,6 +269,7 @@ public:
   enum Functype functype() const { return NOT_FUNC; }
   const char *func_name() const { return "not"; }
   Item *neg_transformer(THD *thd);
+  void print(String *str);
 };
 
 class Item_maxmin_subselect;