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, 27 insertions, 0 deletions

diff --git a/sql/item.cc b/sql/item.cc
index d3888cef9d5..7fbeb6f15db 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -635,6 +635,33 @@ Item *Item_string::safe_charset_converter(CHARSET_INFO *tocs)
 }
 
 
+Item *Item_static_string_func::safe_charset_converter(CHARSET_INFO *tocs)
+{
+  Item_string *conv;
+  uint conv_errors;
+  String tmp, cstr, *ostr= val_str(&tmp);
+  cstr.copy(ostr->ptr(), ostr->length(), ostr->charset(), tocs, &conv_errors);
+  if (conv_errors ||
+      !(conv= new Item_static_string_func(func_name,
+                                          cstr.ptr(), cstr.length(),
+                                          cstr.charset(),
+                                          collation.derivation)))
+  {
+    /*
+      Safe conversion is not possible (or EOM).
+      We could not convert a string into the requested character set
+      without data loss. The target charset does not cover all the
+      characters from the string. Operation cannot be done correctly.
+    */
+    return NULL;
+  }
+  conv->str_value.copy();
+  /* Ensure that no one is going to change the result string */
+  conv->str_value.mark_as_const();
+  return conv;
+}
+
+
 bool Item_string::eq(const Item *item, bool binary_cmp) const
 {
   if (type() == item->type() && item->basic_const_item())