stop evaluation constant functions in WHERE (BUG#4663)

correct value of CURRENT_USER() in SP with "security definer" (BUG#7291)


BitKeeper/etc/config:
  switch off open logging
mysql-test/r/sp-security.result:
  correct value from current_user() in function run from "security definer"
mysql-test/r/view.result:
  evaluation constant functions in WHERE (BUG#4663)
mysql-test/t/sp-security.test:
  correct value from current_user() in function run from "security definer"
mysql-test/t/view.test:
  evaluation constant functions in WHERE (BUG#4663)
sql/item.cc:
  Item_static_string_func creation if it is need
sql/item.h:
  support of Item_static_string_func creation
sql/item_cmpfunc.cc:
  do not evaluate items during view creation
sql/item_create.cc:
  create Item_func_user
sql/item_strfunc.cc:
  Item_func_sysconst in case of converting value still have to correctly print itself
  => use Item_static_string_func instead of Item_string
      Item_func_user return USER() or CURRENT_USER()
sql/item_strfunc.h:
  support of correct charset conversion procedure in Item_func_sysconst
sql/sql_class.h:
  new method
sql/sql_yacc.yy:
  Item_func_user now support both USER() and CURRENT_USER(), so we have to pass parametr what it is

1 files changed, 21 insertions, 5 deletions

diff --git a/sql/item_strfunc.h b/sql/item_strfunc.h
index 8d2eb269915..13073b25130 100644
--- a/sql/item_strfunc.h
+++ b/sql/item_strfunc.h
@@ -356,8 +356,15 @@ public:
   Item_func_sysconst()
   { collation.set(system_charset_info,DERIVATION_SYSCONST); }
   Item *safe_charset_converter(CHARSET_INFO *tocs);
+  /*
+    Used to create correct Item name in new converted item in
+    safe_charset_converter, return string representation of this function
+    call
+  */
+  virtual const char *fully_qualified_func_name() const = 0;
 };
 
+
 class Item_func_database :public Item_func_sysconst
 {
 public:
@@ -369,18 +376,27 @@ public:
     maybe_null=1;
   }
   const char *func_name() const { return "database"; }
+  const char *fully_qualified_func_name() const { return "database()"; }
 };
 
+
 class Item_func_user :public Item_func_sysconst
 {
+  bool is_current;
+
 public:
-  Item_func_user() :Item_func_sysconst() {}
+  Item_func_user(bool is_current_arg)
+    :Item_func_sysconst(), is_current(is_current_arg) {}
   String *val_str(String *);
-  void fix_length_and_dec() 
-  { 
-    max_length= (USERNAME_LENGTH+HOSTNAME_LENGTH+1)*system_charset_info->mbmaxlen;
+  void fix_length_and_dec()
+  {
+    max_length= ((USERNAME_LENGTH + HOSTNAME_LENGTH + 1) *
+                 system_charset_info->mbmaxlen);
   }
-  const char *func_name() const { return "user"; }
+  const char *func_name() const
+    { return is_current ? "current_user" : "user"; }
+  const char *fully_qualified_func_name() const
+    { return is_current ? "current_user()" : "user()"; }
 };