Bug#20570: CURRENT_USER() in a VIEW with SQL SECURITY DEFINER returns

           invoker name

The bug was fixed similar to how context switch is handled in
Item_func_sp::execute_impl(): we store pointer to current
Name_resolution_context in Item_func_current_user class, and use
its Security_context in Item_func_current_user::fix_fields().


mysql-test/r/view_grant.result:
  Add result for bug#20570.
mysql-test/t/view_grant.test:
  Add test case for bug#20570.
sql/item_create.cc:
  Remove create_func_current_user(), as it is not used for automatic
  function creation.
sql/item_create.h:
  Remove prototype for create_func_current_user().
sql/item_strfunc.cc:
  Add implementations for Item_func_user::init(),
  Item_func_user::fix_fields() and
  Item_func_current_user::fix_fields() methods.  The latter uses
  Security_context from current Name_resolution_context, if one is
  defined.
sql/item_strfunc.h:
  Move implementation of CURRENT_USER() out of Item_func_user to
  to new Item_func_current_user class.  For both classes calculate
  user name in fix_fields() method.
  For Item_func_current_user add context field to store
  Name_resolution_context in effect.
sql/sql_yacc.yy:
  Pass current Name_resolution_context to Item_func_current_user.

1 files changed, 0 insertions, 6 deletions

diff --git a/sql/item_create.cc b/sql/item_create.cc
index bfcb2101d60..7d57757432e 100644
--- a/sql/item_create.cc
+++ b/sql/item_create.cc
@@ -296,12 +296,6 @@ Item *create_func_pow(Item* a, Item *b)
   return new Item_func_pow(a,b);
 }
 
-Item *create_func_current_user()
-{
-  current_thd->lex->safe_to_cache_query= 0;
-  return new Item_func_user(TRUE);
-}
-
 Item *create_func_radians(Item *a)
 {
   return new Item_func_units((char*) "radians",a,M_PI/180,0.0);