Use default character set for expressions

- Force usage of () around complex DEFAULT expressions
- Give error if DEFAULT expression contains invalid characters
- Don't use const_charset_conversion for stored Item_func_sysconf expressions
  as the result is not constaint over different executions
- Fixed Item_func_user() to not store calculated value in str_value

1 files changed, 2 insertions, 0 deletions

diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index 5789186dbe8..33e061072da 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -197,6 +197,7 @@ public:
   virtual CHARSET_INFO *compare_collation() const { return NULL; }
   void fix_length_and_dec() { decimals=0; max_length=1; }
   uint decimal_precision() const { return 1; }
+  bool need_parentheses_in_default() { return true; }
 };
 
 
@@ -1488,6 +1489,7 @@ public:
   CHARSET_INFO *compare_collation() const { return cmp_collation.collation; }
   void cleanup();
   Item* propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond);
+  bool need_parentheses_in_default() { return true; }
 };
 
 /*