Adding upstream version 1:10.11.6.upstream/1%10.11.6upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 7309 insertions, 0 deletions

diff --git a/sql/item_func.cc b/sql/item_func.cc
new file mode 100644
index 00000000..a2bc4752
--- /dev/null
+++ b/sql/item_func.cc
@@ -0,0 +1,7309 @@
+/* Copyright (c) 2000, 2015, Oracle and/or its affiliates.
+   Copyright (c) 2009, 2022, MariaDB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
+
+/**
+  @file
+
+  @brief
+  This file defines all numerical functions
+*/
+
+#ifdef USE_PRAGMA_IMPLEMENTATION
+#pragma implementation				// gcc: Class implementation
+#endif
+
+#include "sql_plugin.h"
+#include "sql_priv.h"
+/*
+  It is necessary to include set_var.h instead of item.h because there
+  are dependencies on include order for set_var.h and item.h. This
+  will be resolved later.
+*/
+#include "sql_class.h"                          // set_var.h: THD
+#include "set_var.h"
+#include "slave.h"				// for wait_for_master_pos
+#include "sql_show.h"                           // append_identifier
+#include "strfunc.h"                            // find_type
+#include "sql_parse.h"                          // is_update_query
+#include "sql_acl.h"                            // EXECUTE_ACL
+#include "mysqld.h"                             // LOCK_short_uuid_generator
+#include "rpl_mi.h"
+#include "sql_time.h"
+#include <m_ctype.h>
+#include <hash.h>
+#include <time.h>
+#include <ft_global.h>
+#include <my_bit.h>
+
+#include "sp_head.h"
+#include "sp_rcontext.h"
+#include "sp.h"
+#include "set_var.h"
+#include "debug_sync.h"
+#include "sql_base.h"
+#include "sql_cte.h"
+#ifdef WITH_WSREP
+#include "mysql/service_wsrep.h"
+#endif /* WITH_WSREP */
+
+#ifdef NO_EMBEDDED_ACCESS_CHECKS
+#define sp_restore_security_context(A,B) while (0) {}
+#endif
+
+bool check_reserved_words(const LEX_CSTRING *name)
+{
+  if (lex_string_eq(name, STRING_WITH_LEN("GLOBAL")) ||
+      lex_string_eq(name, STRING_WITH_LEN("LOCAL")) ||
+      lex_string_eq(name, STRING_WITH_LEN("SESSION")))
+    return TRUE;
+  return FALSE;
+}
+
+
+/**
+   Test if the sum of arguments overflows the ulonglong range.
+*/
+static inline bool test_if_sum_overflows_ull(ulonglong arg1, ulonglong arg2)
+{
+  return ULonglong::test_if_sum_overflows_ull(arg1, arg2);
+}
+
+
+/**
+  Allocate memory for arguments using tmp_args or thd->alloc().
+  @retval false  - success
+  @retval true   - error (arg_count is set to 0 for conveniece)
+*/
+bool Item_args::alloc_arguments(THD *thd, uint count)
+{
+  if (count <= 2)
+  {
+    args= tmp_arg;
+    return false;
+  }
+  if ((args= (Item**) thd->alloc(sizeof(Item*) * count)) == NULL)
+  {
+    arg_count= 0;
+    return true;
+  }
+  return false;
+}
+
+
+void Item_args::set_arguments(THD *thd, List<Item> &list)
+{
+  if (alloc_arguments(thd, list.elements))
+    return;
+  List_iterator_fast<Item> li(list);
+  Item *item;
+  for (arg_count= 0; (item= li++); )
+    args[arg_count++]= item;
+}
+
+
+Item_args::Item_args(THD *thd, const Item_args *other)
+  :arg_count(other->arg_count)
+{
+  if (arg_count <= 2)
+  {
+    args= tmp_arg;
+  }
+  else if (!(args= (Item**) thd->alloc(sizeof(Item*) * arg_count)))
+  {
+    arg_count= 0;
+    return;
+  }
+  if (arg_count)
+    memcpy(args, other->args, sizeof(Item*) * arg_count);
+}
+
+
+void Item_func::sync_with_sum_func_and_with_field(List<Item> &list)
+{
+  List_iterator_fast<Item> li(list);
+  Item *item;
+  while ((item= li++))
+    with_flags|= item->with_flags;
+}
+
+
+bool Item_func::check_argument_types_like_args0() const
+{
+  if (arg_count < 2)
+    return false;
+  uint cols= args[0]->cols();
+  bool is_scalar= args[0]->type_handler()->is_scalar_type();
+  for (uint i= 1; i < arg_count; i++)
+  {
+    if (is_scalar != args[i]->type_handler()->is_scalar_type())
+    {
+      my_error(ER_ILLEGAL_PARAMETER_DATA_TYPES2_FOR_OPERATION, MYF(0),
+               args[0]->type_handler()->name().ptr(),
+               args[i]->type_handler()->name().ptr(), func_name());
+      return true;
+    }
+    if (args[i]->check_cols(cols))
+      return true;
+  }
+  return false;
+}
+
+
+bool Item_func::check_argument_types_or_binary(const Type_handler *handler,
+                                               uint start, uint end) const
+{
+  for (uint i= start; i < end ; i++)
+  {
+    DBUG_ASSERT(i < arg_count);
+    if (args[i]->check_type_or_binary(func_name_cstring(), handler))
+      return true;
+  }
+  return false;
+}
+
+
+bool Item_func::check_argument_types_traditional_scalar(uint start,
+                                                        uint end) const
+{
+  for (uint i= start; i < end ; i++)
+  {
+    DBUG_ASSERT(i < arg_count);
+    if (args[i]->check_type_traditional_scalar(func_name_cstring()))
+      return true;
+  }
+  return false;
+}
+
+
+bool Item_func::check_argument_types_can_return_int(uint start,
+                                                    uint end) const
+{
+  for (uint i= start; i < end ; i++)
+  {
+    DBUG_ASSERT(i < arg_count);
+    if (args[i]->check_type_can_return_int(func_name_cstring()))
+      return true;
+  }
+  return false;
+}
+
+
+bool Item_func::check_argument_types_can_return_real(uint start,
+                                                     uint end) const
+{
+  for (uint i= start; i < end ; i++)
+  {
+    DBUG_ASSERT(i < arg_count);
+    if (args[i]->check_type_can_return_real(func_name_cstring()))
+      return true;
+  }
+  return false;
+}
+
+
+bool Item_func::check_argument_types_can_return_text(uint start,
+                                                     uint end) const
+{
+  for (uint i= start; i < end ; i++)
+  {
+    DBUG_ASSERT(i < arg_count);
+    if (args[i]->check_type_can_return_text(func_name_cstring()))
+      return true;
+  }
+  return false;
+}
+
+
+bool Item_func::check_argument_types_can_return_str(uint start,
+                                                    uint end) const
+{
+  for (uint i= start; i < end ; i++)
+  {
+    DBUG_ASSERT(i < arg_count);
+    if (args[i]->check_type_can_return_str(func_name_cstring()))
+      return true;
+  }
+  return false;
+}
+
+
+bool Item_func::check_argument_types_can_return_date(uint start,
+                                                     uint end) const
+{
+  for (uint i= start; i < end ; i++)
+  {
+    DBUG_ASSERT(i < arg_count);
+    if (args[i]->check_type_can_return_date(func_name_cstring()))
+      return true;
+  }
+  return false;
+}
+
+
+bool Item_func::check_argument_types_can_return_time(uint start,
+                                                     uint end) const
+{
+  for (uint i= start; i < end ; i++)
+  {
+    DBUG_ASSERT(i < arg_count);
+    if (args[i]->check_type_can_return_time(func_name_cstring()))
+      return true;
+  }
+  return false;
+}
+
+
+bool Item_func::check_argument_types_scalar(uint start, uint end) const
+{
+  for (uint i= start; i < end; i++)
+  {
+    DBUG_ASSERT(i < arg_count);
+    if (args[i]->check_type_scalar(func_name_cstring()))
+      return true;
+  }
+  return false;
+}
+
+
+/*
+  Resolve references to table column for a function and its argument
+
+  SYNOPSIS:
+  fix_fields()
+  thd		Thread object
+  ref		Pointer to where this object is used.  This reference
+		is used if we want to replace this object with another
+		one (for example in the summary functions).
+
+  DESCRIPTION
+    Call fix_fields() for all arguments to the function.  The main intention
+    is to allow all Item_field() objects to setup pointers to the table fields.
+
+    Sets as a side effect the following class variables:
+      maybe_null        Set if any argument may return NULL
+      with_sum_func     Set if any of the arguments contains a sum function
+      with_window_func()  Set if any of the arguments contain a window function
+      with_field        Set if any of the arguments contains or is a field
+      used_tables_cache Set to union of the tables used by arguments
+
+      str_value.charset If this is a string function, set this to the
+			character set for the first argument.
+			If any argument is binary, this is set to binary
+
+   If for any item any of the defaults are wrong, then this can
+   be fixed in the fix_length_and_dec() function that is called
+   after this one or by writing a specialized fix_fields() for the
+   item.
+
+  RETURN VALUES
+  FALSE	ok
+  TRUE	Got error.  Stored with my_error().
+*/
+
+bool
+Item_func::fix_fields(THD *thd, Item **ref)
+{
+  DBUG_ASSERT(fixed() == 0);
+  Item **arg,**arg_end;
+  uchar buff[STACK_BUFF_ALLOC];			// Max argument in function
+
+  /*
+    The Used_tables_and_const_cache of "this" was initialized by
+    the constructor, or by Item_func::cleanup().
+  */
+  DBUG_ASSERT(used_tables_cache == 0);
+  DBUG_ASSERT(const_item_cache == true);
+
+  not_null_tables_cache= 0;
+
+  /*
+    Use stack limit of STACK_MIN_SIZE * 2 since
+    on some platforms a recursive call to fix_fields
+    requires more than STACK_MIN_SIZE bytes (e.g. for
+    MIPS, it takes about 22kB to make one recursive
+    call to Item_func::fix_fields())
+  */
+  if (check_stack_overrun(thd, STACK_MIN_SIZE * 2, buff))
+    return TRUE;				// Fatal error if flag is set!
+  if (arg_count)
+  {						// Print purify happy
+    for (arg=args, arg_end=args+arg_count; arg != arg_end ; arg++)
+    {
+      Item *item;
+      /*
+	We can't yet set item to *arg as fix_fields may change *arg
+	We shouldn't call fix_fields() twice, so check 'fixed' field first
+      */
+      if ((*arg)->fix_fields_if_needed(thd, arg))
+      {
+        cleanup();
+	return TRUE;				/* purecov: inspected */
+      }
+      item= *arg;
+
+      base_flags|= item->base_flags & item_base_t::MAYBE_NULL;
+      with_flags|= item->with_flags;
+      used_tables_and_const_cache_join(item);
+      not_null_tables_cache|= item->not_null_tables();
+    }
+  }
+  if (check_arguments())
+  {
+    cleanup();
+    return true;
+  }
+  if (fix_length_and_dec(thd))
+  {
+    cleanup();
+    return TRUE;
+  }
+  base_flags|= item_base_t::FIXED;
+  return FALSE;
+}
+
+void
+Item_func::quick_fix_field()
+{
+  Item **arg,**arg_end;
+  if (arg_count)
+  {
+    for (arg=args, arg_end=args+arg_count; arg != arg_end ; arg++)
+    {
+      if (!(*arg)->fixed())
+        (*arg)->quick_fix_field();
+    }
+  }
+  base_flags|= item_base_t::FIXED;
+}
+
+
+bool
+Item_func::eval_not_null_tables(void *opt_arg)
+{
+  Item **arg,**arg_end;
+  not_null_tables_cache= 0;
+  if (arg_count)
+  {		
+    for (arg=args, arg_end=args+arg_count; arg != arg_end ; arg++)
+    {
+      not_null_tables_cache|= (*arg)->not_null_tables();
+    }
+  }
+  return FALSE;
+}
+
+
+bool
+Item_func::find_not_null_fields(table_map allowed)
+{
+  if (~allowed & used_tables())
+    return false;
+
+  Item **arg,**arg_end;
+  if (arg_count)
+  {
+    for (arg=args, arg_end=args+arg_count; arg != arg_end ; arg++)
+    {
+      if (!(*arg)->find_not_null_fields(allowed))
+        continue;
+    }
+  }
+  return false;
+}
+
+
+void Item_func::fix_after_pullout(st_select_lex *new_parent, Item **ref,
+                                  bool merge)
+{
+  Item **arg,**arg_end;
+
+  used_tables_and_const_cache_init();
+  not_null_tables_cache= 0;
+
+  if (arg_count)
+  {
+    for (arg=args, arg_end=args+arg_count; arg != arg_end ; arg++)
+    {
+      (*arg)->fix_after_pullout(new_parent, arg, merge);
+      Item *item= *arg;
+
+      used_tables_and_const_cache_join(item);
+      not_null_tables_cache|= item->not_null_tables();
+    }
+  }
+}
+
+
+void Item_func::traverse_cond(Cond_traverser traverser,
+                              void *argument, traverse_order order)
+{
+  if (arg_count)
+  {
+    Item **arg,**arg_end;
+
+    switch (order) {
+    case(PREFIX):
+      (*traverser)(this, argument);
+      for (arg= args, arg_end= args+arg_count; arg != arg_end; arg++)
+      {
+	(*arg)->traverse_cond(traverser, argument, order);
+      }
+      break;
+    case (POSTFIX):
+      for (arg= args, arg_end= args+arg_count; arg != arg_end; arg++)
+      {
+	(*arg)->traverse_cond(traverser, argument, order);
+      }
+      (*traverser)(this, argument);
+    }
+  }
+  else
+    (*traverser)(this, argument);
+}
+
+
+bool Item_args::transform_args(THD *thd, Item_transformer transformer, uchar *arg)
+{
+  for (uint i= 0; i < arg_count; i++)
+  {
+    Item *new_item= args[i]->transform(thd, transformer, arg);
+    if (!new_item)
+      return true;
+    /*
+      THD::change_item_tree() should be called only if the tree was
+      really transformed, i.e. when a new item has been created.
+      Otherwise we'll be allocating a lot of unnecessary memory for
+      change records at each execution.
+    */
+    if (args[i] != new_item)
+      thd->change_item_tree(&args[i], new_item);
+  }
+  return false;
+}
+
+
+/**
+  Transform an Item_func object with a transformer callback function.
+
+    The function recursively applies the transform method to each
+    argument of the Item_func node.
+    If the call of the method for an argument item returns a new item
+    the old item is substituted for a new one.
+    After this the transformer is applied to the root node
+    of the Item_func object. 
+  @param transformer   the transformer callback function to be applied to
+                       the nodes of the tree of the object
+  @param argument      parameter to be passed to the transformer
+
+  @return
+    Item returned as the result of transformation of the root node
+*/
+
+Item *Item_func::transform(THD *thd, Item_transformer transformer, uchar *argument)
+{
+  DBUG_ASSERT(!thd->stmt_arena->is_stmt_prepare());
+  if (transform_args(thd, transformer, argument))
+    return 0;
+  return (this->*transformer)(thd, argument);
+}
+
+
+/**
+  Compile Item_func object with a processor and a transformer
+  callback functions.
+
+    First the function applies the analyzer to the root node of
+    the Item_func object. Then if the analyzer succeeds (returns TRUE)
+    the function recursively applies the compile method to each argument
+    of the Item_func node.
+    If the call of the method for an argument item returns a new item
+    the old item is substituted for a new one.
+    After this the transformer is applied to the root node
+    of the Item_func object. 
+    The compile function is not called if the analyzer returns NULL
+    in the parameter arg_p. 
+
+  @param analyzer      the analyzer callback function to be applied to the
+                       nodes of the tree of the object
+  @param[in,out] arg_p parameter to be passed to the processor
+  @param transformer   the transformer callback function to be applied to the
+                       nodes of the tree of the object
+  @param arg_t         parameter to be passed to the transformer
+
+  @return
+    Item returned as the result of transformation of the root node
+*/
+
+Item *Item_func::compile(THD *thd, Item_analyzer analyzer, uchar **arg_p,
+                         Item_transformer transformer, uchar *arg_t)
+{
+  if (!(this->*analyzer)(arg_p))
+    return 0;
+  if (*arg_p && arg_count)
+  {
+    Item **arg,**arg_end;
+    for (arg= args, arg_end= args+arg_count; arg != arg_end; arg++)
+    {
+      /* 
+        The same parameter value of arg_p must be passed
+        to analyze any argument of the condition formula.
+      */
+      uchar *arg_v= *arg_p;
+      Item *new_item= (*arg)->compile(thd, analyzer, &arg_v, transformer,
+                                      arg_t);
+      if (new_item && *arg != new_item)
+        thd->change_item_tree(arg, new_item);
+    }
+  }
+  return (this->*transformer)(thd, arg_t);
+}
+
+
+void Item_args::propagate_equal_fields(THD *thd,
+                                       const Item::Context &ctx,
+                                       COND_EQUAL *cond)
+{
+  uint i;
+  for (i= 0; i < arg_count; i++)
+    args[i]->propagate_equal_fields_and_change_item_tree(thd, ctx, cond,
+                                                         &args[i]);
+}
+
+
+Sql_mode_dependency Item_args::value_depends_on_sql_mode_bit_or() const
+{
+  Sql_mode_dependency res;
+  for (uint i= 0; i < arg_count; i++)
+    res|= args[i]->value_depends_on_sql_mode();
+  return res;
+}
+
+
+/**
+  See comments in Item_cond::split_sum_func()
+*/
+
+void Item_func::split_sum_func(THD *thd,  Ref_ptr_array ref_pointer_array,
+                               List<Item> &fields, uint flags)
+{
+  Item **arg, **arg_end;
+  DBUG_ENTER("Item_func::split_sum_func");
+
+  for (arg= args, arg_end= args+arg_count; arg != arg_end ; arg++)
+    (*arg)->split_sum_func2(thd, ref_pointer_array, fields, arg,
+                            flags | SPLIT_SUM_SKIP_REGISTERED);
+  DBUG_VOID_RETURN;
+}
+
+
+table_map Item_func::not_null_tables() const
+{
+  return not_null_tables_cache;
+}
+
+
+void Item_func::print(String *str, enum_query_type query_type)
+{
+  str->append(func_name_cstring());
+  str->append('(');
+  print_args(str, 0, query_type);
+  str->append(')');
+}
+
+
+void Item_func::print_args(String *str, uint from, enum_query_type query_type)
+{
+  for (uint i=from ; i < arg_count ; i++)
+  {
+    if (i != from)
+      str->append(',');
+    args[i]->print(str, query_type);
+  }
+}
+
+
+void Item_func::print_op(String *str, enum_query_type query_type)
+{
+  for (uint i=0 ; i < arg_count-1 ; i++)
+  {
+    args[i]->print_parenthesised(str, query_type, precedence());
+    str->append(' ');
+    str->append(func_name_cstring());
+    str->append(' ');
+  }
+  args[arg_count-1]->print_parenthesised(str, query_type, higher_precedence());
+}
+
+
+bool Item_func::eq(const Item *item, bool binary_cmp) const
+{
+  /* Assume we don't have rtti */
+  if (this == item)
+    return 1;
+  /*
+    Ensure that we are comparing two functions and that the function
+    is deterministic.
+  */
+  if (item->type() != FUNC_ITEM || (used_tables() & RAND_TABLE_BIT))
+    return 0;
+  Item_func *item_func=(Item_func*) item;
+  Item_func::Functype func_type;
+  if ((func_type= functype()) != item_func->functype() ||
+      arg_count != item_func->arg_count ||
+      (func_type != Item_func::FUNC_SP &&
+       func_name() != item_func->func_name()) ||
+      (func_type == Item_func::FUNC_SP &&
+       my_strcasecmp(system_charset_info, func_name(), item_func->func_name())))
+    return 0;
+  return Item_args::eq(item_func, binary_cmp);
+}
+
+
+/*
+bool Item_func::is_expensive_processor(uchar *arg)
+{
+  return is_expensive();
+}
+*/
+
+
+bool Item_hybrid_func::fix_attributes(Item **items, uint nitems)
+{
+  bool rc= Item_hybrid_func::type_handler()->
+             Item_hybrid_func_fix_attributes(current_thd,
+                                             func_name_cstring(), this, this,
+                                             items, nitems);
+  DBUG_ASSERT(!rc || current_thd->is_error());
+  return rc;
+}
+
+
+String *Item_real_func::val_str(String *str)
+{
+  DBUG_ASSERT(fixed());
+  double nr= val_real();
+  if (null_value)
+    return 0; /* purecov: inspected */
+  str->set_real(nr, decimals, collation.collation);
+  return str;
+}
+
+
+my_decimal *Item_real_func::val_decimal(my_decimal *decimal_value)
+{
+  DBUG_ASSERT(fixed());
+  double nr= val_real();
+  if (null_value)
+    return 0; /* purecov: inspected */
+  double2my_decimal(E_DEC_FATAL_ERROR, nr, decimal_value);
+  return decimal_value;
+}
+
+
+#ifdef HAVE_DLOPEN
+void Item_udf_func::fix_num_length_and_dec()
+{
+  uint fl_length= 0;
+  decimals=0;
+  for (uint i=0 ; i < arg_count ; i++)
+  {
+    set_if_bigger(decimals,args[i]->decimals);
+    set_if_bigger(fl_length, args[i]->max_length);
+  }
+  max_length=float_length(decimals);
+  if (fl_length > max_length)
+  {
+    decimals= NOT_FIXED_DEC;
+    max_length= float_length(NOT_FIXED_DEC);
+  }
+}
+#endif
+
+
+void Item_func::signal_divide_by_null()
+{
+  THD *thd= current_thd;
+  if (thd->variables.sql_mode & MODE_ERROR_FOR_DIVISION_BY_ZERO)
+    push_warning(thd, Sql_condition::WARN_LEVEL_WARN, ER_DIVISION_BY_ZERO,
+                 ER_THD(thd, ER_DIVISION_BY_ZERO));
+  null_value= 1;
+}
+
+
+Item *Item_func::get_tmp_table_item(THD *thd)
+{
+  if (!with_sum_func() && !const_item())
+  {
+    auto item_field= new (thd->mem_root) Item_field(thd, result_field);
+    if (item_field)
+      item_field->set_refers_to_temp_table();
+    return item_field;
+  }
+  return copy_or_same(thd);
+}
+
+double Item_int_func::val_real()
+{
+  DBUG_ASSERT(fixed());
+
+  return unsigned_flag ? (double) ((ulonglong) val_int()) : (double) val_int();
+}
+
+
+String *Item_int_func::val_str(String *str)
+{
+  DBUG_ASSERT(fixed());
+  longlong nr=val_int();
+  if (null_value)
+    return 0;
+  str->set_int(nr, unsigned_flag, collation.collation);
+  return str;
+}
+
+
+bool Item_func_connection_id::fix_length_and_dec(THD *thd)
+{
+  if (Item_long_func::fix_length_and_dec(thd))
+    return TRUE;
+  max_length= 10;
+  return FALSE;
+}
+
+
+bool Item_func_connection_id::fix_fields(THD *thd, Item **ref)
+{
+  if (Item_int_func::fix_fields(thd, ref))
+    return TRUE;
+  thd->used|= THD::THREAD_SPECIFIC_USED;
+  value= thd->variables.pseudo_thread_id;
+  return FALSE;
+}
+
+
+bool Item_num_op::fix_type_handler(const Type_aggregator *aggregator)
+{
+  DBUG_ASSERT(arg_count == 2);
+  const Type_handler *h0= args[0]->cast_to_int_type_handler();
+  const Type_handler *h1= args[1]->cast_to_int_type_handler();
+  if (!aggregate_for_num_op(aggregator, h0, h1))
+    return false;
+  my_error(ER_ILLEGAL_PARAMETER_DATA_TYPES2_FOR_OPERATION, MYF(0),
+           h0->name().ptr(), h1->name().ptr(), func_name());
+  return true;
+}
+
+
+bool Item_func_plus::fix_length_and_dec(THD *thd)
+{
+  DBUG_ENTER("Item_func_plus::fix_length_and_dec");
+  DBUG_PRINT("info", ("name %s", func_name()));
+  const Type_aggregator *aggregator= &type_handler_data->m_type_aggregator_for_plus;
+  DBUG_EXECUTE_IF("num_op", aggregator= &type_handler_data->m_type_aggregator_for_result;);
+  DBUG_ASSERT(aggregator->is_commutative());
+  if (fix_type_handler(aggregator))
+    DBUG_RETURN(TRUE);
+  if (Item_func_plus::type_handler()->Item_func_plus_fix_length_and_dec(this))
+    DBUG_RETURN(TRUE);
+  DBUG_PRINT("info", ("Type: %s", type_handler()->name().ptr()));
+  DBUG_RETURN(FALSE);
+}
+
+
+String *Item_func_hybrid_field_type::val_str_from_int_op(String *str)
+{
+  longlong nr= int_op();
+  if (null_value)
+    return 0; /* purecov: inspected */
+  str->set_int(nr, unsigned_flag, collation.collation);
+  return str;
+}
+
+double Item_func_hybrid_field_type::val_real_from_int_op()
+{
+  longlong result= int_op();
+  return unsigned_flag ? (double) ((ulonglong) result) : (double) result;
+}
+
+my_decimal *
+Item_func_hybrid_field_type::val_decimal_from_int_op(my_decimal *dec)
+{
+  longlong result= int_op();
+  if (null_value)
+    return NULL;
+  int2my_decimal(E_DEC_FATAL_ERROR, result, unsigned_flag, dec);
+  return dec;
+}
+
+
+String *Item_func_hybrid_field_type::val_str_from_real_op(String *str)
+{
+  double nr= real_op();
+  if (null_value)
+    return 0; /* purecov: inspected */
+  str->set_real(nr, decimals, collation.collation);
+  return str;
+}
+
+longlong Item_func_hybrid_field_type::val_int_from_real_op()
+{
+  return Converter_double_to_longlong(real_op(), unsigned_flag).result();
+}
+
+my_decimal *
+Item_func_hybrid_field_type::val_decimal_from_real_op(my_decimal *dec)
+{
+  double result= (double) real_op();
+  if (null_value)
+    return NULL;
+  double2my_decimal(E_DEC_FATAL_ERROR, result, dec);
+  return dec;
+}
+
+
+String *Item_func_hybrid_field_type::val_str_from_date_op(String *str)
+{
+  MYSQL_TIME ltime;
+  if (date_op_with_null_check(current_thd, &ltime) ||
+      (null_value= str->alloc(MAX_DATE_STRING_REP_LENGTH)))
+    return (String *) 0;
+  str->length(my_TIME_to_str(&ltime, const_cast<char*>(str->ptr()), decimals));
+  str->set_charset(&my_charset_bin);
+  DBUG_ASSERT(!null_value);
+  return str;
+}
+
+double Item_func_hybrid_field_type::val_real_from_date_op()
+{
+  MYSQL_TIME ltime;
+  if (date_op_with_null_check(current_thd, &ltime))
+    return 0;
+  return TIME_to_double(&ltime);
+}
+
+longlong Item_func_hybrid_field_type::val_int_from_date_op()
+{
+  MYSQL_TIME ltime;
+  if (date_op_with_null_check(current_thd, &ltime))
+    return 0;
+  return TIME_to_ulonglong(&ltime);
+}
+
+my_decimal *
+Item_func_hybrid_field_type::val_decimal_from_date_op(my_decimal *dec)
+{
+  MYSQL_TIME ltime;
+  if (date_op_with_null_check(current_thd, &ltime))
+  {
+    my_decimal_set_zero(dec);
+    return 0;
+  }
+  return date2my_decimal(&ltime, dec);
+}
+
+
+String *Item_func_hybrid_field_type::val_str_from_time_op(String *str)
+{
+  MYSQL_TIME ltime;
+  if (time_op_with_null_check(current_thd, &ltime) ||
+      (null_value= my_TIME_to_str(&ltime, str, decimals)))
+    return NULL;
+  return str;
+}
+
+double Item_func_hybrid_field_type::val_real_from_time_op()
+{
+  MYSQL_TIME ltime;
+  return time_op_with_null_check(current_thd, &ltime) ? 0 :
+         TIME_to_double(&ltime);
+}
+
+longlong Item_func_hybrid_field_type::val_int_from_time_op()
+{
+  MYSQL_TIME ltime;
+  return time_op_with_null_check(current_thd, &ltime) ? 0 :
+         TIME_to_ulonglong(&ltime);
+}
+
+my_decimal *
+Item_func_hybrid_field_type::val_decimal_from_time_op(my_decimal *dec)
+{
+  MYSQL_TIME ltime;
+  if (time_op_with_null_check(current_thd, &ltime))
+  {
+    my_decimal_set_zero(dec);
+    return 0;
+  }
+  return date2my_decimal(&ltime, dec);
+}
+
+
+double Item_func_hybrid_field_type::val_real_from_str_op()
+{
+  String *res= str_op_with_null_check(&str_value);
+  return res ? double_from_string_with_check(res) : 0.0;
+}
+
+longlong Item_func_hybrid_field_type::val_int_from_str_op()
+{
+  String *res= str_op_with_null_check(&str_value);
+  return res ? longlong_from_string_with_check(res) : 0;
+}
+
+my_decimal *
+Item_func_hybrid_field_type::val_decimal_from_str_op(my_decimal *decimal_value)
+{
+  String *res= str_op_with_null_check(&str_value);
+  return res ? decimal_from_string_with_check(decimal_value, res) : 0;
+}
+
+
+void Item_func_signed::print(String *str, enum_query_type query_type)
+{
+  str->append(STRING_WITH_LEN("cast("));
+  args[0]->print(str, query_type);
+  str->append(STRING_WITH_LEN(" as signed)"));
+
+}
+
+
+void Item_func_unsigned::print(String *str, enum_query_type query_type)
+{
+  str->append(STRING_WITH_LEN("cast("));
+  args[0]->print(str, query_type);
+  str->append(STRING_WITH_LEN(" as unsigned)"));
+
+}
+
+
+my_decimal *Item_decimal_typecast::val_decimal(my_decimal *dec)
+{
+  VDec tmp(args[0]);
+  bool sign;
+  uint precision;
+
+  if ((null_value= tmp.is_null()))
+    return NULL;
+  tmp.round_to(dec, decimals, HALF_UP);
+  sign= dec->sign();
+  if (unsigned_flag)
+  {
+    if (sign)
+    {
+      my_decimal_set_zero(dec);
+      goto err;
+    }
+  }
+  precision= my_decimal_length_to_precision(max_length,
+                                            decimals, unsigned_flag);
+  if (precision - decimals < (uint) my_decimal_intg(dec))
+  {
+    max_my_decimal(dec, precision, decimals);
+    dec->sign(sign);
+    goto err;
+  }
+  return dec;
+
+err:
+  THD *thd= current_thd;
+  push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
+                      ER_WARN_DATA_OUT_OF_RANGE,
+                      ER_THD(thd, ER_WARN_DATA_OUT_OF_RANGE),
+                      name.str,
+                      thd->get_stmt_da()->current_row_for_warning());
+  return dec;
+}
+
+
+void Item_decimal_typecast::print(String *str, enum_query_type query_type)
+{
+  char len_buf[20*3 + 1];
+  char *end;
+
+  uint precision= my_decimal_length_to_precision(max_length, decimals,
+                                                 unsigned_flag);
+  str->append(STRING_WITH_LEN("cast("));
+  args[0]->print(str, query_type);
+  str->append(STRING_WITH_LEN(" as decimal("));
+
+  end=int10_to_str(precision, len_buf,10);
+  str->append(len_buf, (uint32) (end - len_buf));
+
+  str->append(',');
+
+  end=int10_to_str(decimals, len_buf,10);
+  str->append(len_buf, (uint32) (end - len_buf));
+
+  str->append(')');
+  str->append(')');
+}
+
+
+double Item_real_typecast::val_real_with_truncate(double max_value)
+{
+  int error;
+  double tmp= args[0]->val_real();
+  if ((null_value= args[0]->null_value))
+    return 0.0;
+
+  if (unlikely((error= truncate_double(&tmp, max_length, decimals,
+                                       false/*unsigned_flag*/, max_value))))
+  {
+    /*
+      We don't want automatic escalation from a warning to an error
+      in this scenario:
+        INSERT INTO t1 (float_field) VALUES (CAST(1e100 AS FLOAT));
+      The above statement should work even in the strict mode.
+      So let's use a note rather than a warning.
+    */
+    THD *thd= current_thd;
+    push_warning_printf(thd,
+                        Sql_condition::WARN_LEVEL_NOTE,
+                        ER_WARN_DATA_OUT_OF_RANGE,
+                        ER_THD(thd, ER_WARN_DATA_OUT_OF_RANGE),
+                        name.str, (ulong) 1);
+    if (error < 0)
+    {
+      null_value= 1;                            // Illegal value
+      tmp= 0.0;
+    }
+  }
+  return tmp;
+}
+
+
+void Item_real_typecast::print(String *str, enum_query_type query_type)
+{
+  char len_buf[20*3 + 1];
+  char *end;
+  Name name= type_handler()->name();
+
+  str->append(STRING_WITH_LEN("cast("));
+  args[0]->print(str, query_type);
+  str->append(STRING_WITH_LEN(" as "));
+  str->append(name.ptr(), name.length());
+  if (decimals != NOT_FIXED_DEC)
+  {
+    str->append('(');
+    end= int10_to_str(max_length, len_buf,10);
+    str->append(len_buf, (uint32) (end - len_buf));
+    str->append(',');
+    end= int10_to_str(decimals, len_buf,10);
+    str->append(len_buf, (uint32) (end - len_buf));
+    str->append(')');
+  }
+  str->append(')');
+}
+
+double Item_func_plus::real_op()
+{
+  double value= args[0]->val_real() + args[1]->val_real();
+  if ((null_value=args[0]->null_value || args[1]->null_value))
+    return 0.0;
+  return check_float_overflow(value);
+}
+
+#if defined(__powerpc64__) && GCC_VERSION >= 6003 && GCC_VERSION <= 10002
+#pragma GCC push_options
+#pragma GCC optimize ("no-expensive-optimizations")
+#endif
+
+longlong Item_func_plus::int_op()
+{
+  longlong val0= args[0]->val_int();
+  longlong val1= args[1]->val_int();
+  bool     res_unsigned= FALSE;
+  longlong res;
+
+  if ((null_value= args[0]->null_value || args[1]->null_value))
+    return 0;
+  /*
+    First check whether the result can be represented as a
+    (bool unsigned_flag, longlong value) pair, then check if it is compatible
+    with this Item's unsigned_flag by calling check_integer_overflow().
+  */
+  if (args[0]->unsigned_flag)
+  {
+    if (args[1]->unsigned_flag || val1 >= 0)
+    {
+      if (test_if_sum_overflows_ull((ulonglong) val0, (ulonglong) val1))
+        goto err;
+      res_unsigned= TRUE;
+    }
+    else
+    {
+      /* val1 is negative */
+      if ((ulonglong) val0 > (ulonglong) LONGLONG_MAX)
+        res_unsigned= TRUE;
+    }
+  }
+  else
+  {
+    if (args[1]->unsigned_flag)
+    {
+      if (val0 >= 0)
+      {
+        if (test_if_sum_overflows_ull((ulonglong) val0, (ulonglong) val1))
+          goto err;
+        res_unsigned= TRUE;
+      }
+      else
+      {
+        if ((ulonglong) val1 > (ulonglong) LONGLONG_MAX)
+          res_unsigned= TRUE;
+      }
+    }
+    else
+    {
+      if (val0 >=0 && val1 >= 0)
+        res_unsigned= TRUE;
+      else if (val0 < 0 && val1 < 0 && val0 < (LONGLONG_MIN - val1))
+        goto err;
+    }
+  }
+
+  if (res_unsigned)
+    res= (longlong) ((ulonglong) val0 + (ulonglong) val1);
+  else
+    res= val0 + val1;
+
+  return check_integer_overflow(res, res_unsigned);
+
+err:
+  return raise_integer_overflow();
+}
+
+#if defined(__powerpc64__) && GCC_VERSION >= 6003 && GCC_VERSION <= 10002
+#pragma GCC pop_options
+#endif
+
+/**
+  Calculate plus of two decimals.
+
+  @param decimal_value	Buffer that can be used to store result
+
+  @retval
+    0  Value was NULL;  In this case null_value is set
+  @retval
+    \# Value of operation as a decimal
+*/
+
+my_decimal *Item_func_plus::decimal_op(my_decimal *decimal_value)
+{
+  VDec2_lazy val(args[0], args[1]);
+  if (!(null_value= (val.has_null() ||
+                     check_decimal_overflow(my_decimal_add(E_DEC_FATAL_ERROR &
+                                                           ~E_DEC_OVERFLOW,
+                                                           decimal_value,
+                                                           val.m_a.ptr(),
+                                                           val.m_b.ptr())) > 3)))
+    return decimal_value;
+  return 0;
+}
+
+/**
+  Set precision of results for additive operations (+ and -)
+*/
+void Item_func_additive_op::result_precision()
+{
+  decimals= MY_MAX(args[0]->decimal_scale(), args[1]->decimal_scale());
+  int arg1_int= args[0]->decimal_precision() - args[0]->decimal_scale();
+  int arg2_int= args[1]->decimal_precision() - args[1]->decimal_scale();
+  int precision= MY_MAX(arg1_int, arg2_int) + 1 + decimals;
+
+  DBUG_ASSERT(arg1_int >= 0);
+  DBUG_ASSERT(arg2_int >= 0);
+
+  max_length= my_decimal_precision_to_length_no_truncation(precision, decimals,
+                                                           unsigned_flag);
+}
+
+
+/**
+  The following function is here to allow the user to force
+  subtraction of UNSIGNED BIGINT to return negative values.
+*/
+void Item_func_minus::fix_unsigned_flag()
+{
+  if (unsigned_flag &&
+      (current_thd->variables.sql_mode & MODE_NO_UNSIGNED_SUBTRACTION))
+  {
+    unsigned_flag=0;
+    set_handler(Item_func_minus::type_handler()->type_handler_signed());
+  }
+}
+
+
+bool Item_func_minus::fix_length_and_dec(THD *thd)
+{
+  DBUG_ENTER("Item_func_minus::fix_length_and_dec");
+  DBUG_PRINT("info", ("name %s", func_name()));
+  const Type_aggregator *aggregator= &type_handler_data->m_type_aggregator_for_minus;
+  DBUG_EXECUTE_IF("num_op", aggregator= &type_handler_data->m_type_aggregator_non_commutative_test;);
+  DBUG_ASSERT(!aggregator->is_commutative());
+  if (fix_type_handler(aggregator))
+    DBUG_RETURN(TRUE);
+  if (Item_func_minus::type_handler()->Item_func_minus_fix_length_and_dec(this))
+    DBUG_RETURN(TRUE);
+  DBUG_PRINT("info", ("Type: %s", type_handler()->name().ptr()));
+  m_depends_on_sql_mode_no_unsigned_subtraction= unsigned_flag;
+  fix_unsigned_flag();
+  DBUG_RETURN(FALSE);
+}
+
+
+Sql_mode_dependency Item_func_minus::value_depends_on_sql_mode() const
+{
+  Sql_mode_dependency dep= Item_func_additive_op::value_depends_on_sql_mode();
+  if (m_depends_on_sql_mode_no_unsigned_subtraction)
+    dep|= Sql_mode_dependency(0, MODE_NO_UNSIGNED_SUBTRACTION);
+  return dep;
+}
+
+
+double Item_func_minus::real_op()
+{
+  double value= args[0]->val_real() - args[1]->val_real();
+  if ((null_value=args[0]->null_value || args[1]->null_value))
+    return 0.0;
+  return check_float_overflow(value);
+}
+
+
+#if defined(__powerpc64__) && GCC_VERSION >= 6003 && GCC_VERSION <= 10002
+#pragma GCC push_options
+#pragma GCC optimize ("no-expensive-optimizations")
+#endif
+
+longlong Item_func_minus::int_op()
+{
+  longlong val0= args[0]->val_int();
+  longlong val1= args[1]->val_int();
+  bool     res_unsigned= FALSE;
+  longlong res;
+
+  if ((null_value= args[0]->null_value || args[1]->null_value))
+    return 0;
+
+  /*
+    First check whether the result can be represented as a
+    (bool unsigned_flag, longlong value) pair, then check if it is compatible
+    with this Item's unsigned_flag by calling check_integer_overflow().
+  */
+  if (args[0]->unsigned_flag)
+  {
+    if (args[1]->unsigned_flag)
+    {
+      if ((ulonglong) val0 < (ulonglong) val1)
+        goto err;
+      res_unsigned= TRUE;
+    }
+    else
+    {
+      if (val1 >= 0)
+      {
+        if ((ulonglong) val0 > (ulonglong) val1)
+          res_unsigned= TRUE;
+      }
+      else
+      {
+        if (test_if_sum_overflows_ull((ulonglong) val0, (ulonglong) -val1))
+          goto err;
+        res_unsigned= TRUE;
+      }
+    }
+  }
+  else
+  {
+    if (args[1]->unsigned_flag)
+    {
+      if (((ulonglong) val0 - (ulonglong) LONGLONG_MIN) < (ulonglong) val1)
+        goto err;
+    }
+    else
+    {
+      if (val0 > 0 && val1 < 0)
+        res_unsigned= TRUE;
+      else if (val0 < 0 && val1 > 0 && val0 < (LONGLONG_MIN + val1))
+        goto err;
+    }
+  }
+  if (res_unsigned)
+    res= (longlong) ((ulonglong) val0 - (ulonglong) val1);
+  else
+    res= val0 - val1;
+
+  return check_integer_overflow(res, res_unsigned);
+
+err:
+  return raise_integer_overflow();
+}
+
+#if defined(__powerpc64__) && GCC_VERSION >= 6003 && GCC_VERSION <= 10002
+#pragma GCC pop_options
+#endif
+
+/**
+  See Item_func_plus::decimal_op for comments.
+*/
+
+my_decimal *Item_func_minus::decimal_op(my_decimal *decimal_value)
+{
+  VDec2_lazy val(args[0], args[1]);
+  if (!(null_value= (val.has_null() ||
+                     check_decimal_overflow(my_decimal_sub(E_DEC_FATAL_ERROR &
+                                                           ~E_DEC_OVERFLOW,
+                                                           decimal_value,
+                                                           val.m_a.ptr(),
+                                                           val.m_b.ptr())) > 3)))
+    return decimal_value;
+  return 0;
+}
+
+
+double Item_func_mul::real_op()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real() * args[1]->val_real();
+  if ((null_value=args[0]->null_value || args[1]->null_value))
+    return 0.0;
+  return check_float_overflow(value);
+}
+
+
+longlong Item_func_mul::int_op()
+{
+  DBUG_ASSERT(fixed());
+  /*
+    Since we also have to take the unsigned_flag for a and b into account,
+    it is easier to first work with absolute values and set the
+    correct sign later.
+  */
+  Longlong_hybrid_null ha= args[0]->to_longlong_hybrid_null();
+  Longlong_hybrid_null hb= args[1]->to_longlong_hybrid_null();
+
+  if ((null_value= ha.is_null() || hb.is_null()))
+    return 0;
+
+  ULonglong_null ures= ULonglong_null::ullmul(ha.abs(), hb.abs());
+  if (ures.is_null())
+    return raise_integer_overflow();
+
+  return check_integer_overflow(ULonglong_hybrid(ures.value(),
+                                                 ha.neg() != hb.neg()));
+}
+
+
+/** See Item_func_plus::decimal_op for comments. */
+
+my_decimal *Item_func_mul::decimal_op(my_decimal *decimal_value)
+{
+  VDec2_lazy val(args[0], args[1]);
+  if (!(null_value= (val.has_null() ||
+                     check_decimal_overflow(my_decimal_mul(E_DEC_FATAL_ERROR &
+                                                           ~E_DEC_OVERFLOW,
+                                                           decimal_value,
+                                                           val.m_a.ptr(),
+                                                           val.m_b.ptr())) > 3)))
+    return decimal_value;
+  return 0;
+}
+
+
+void Item_func_mul::result_precision()
+{
+  decimals= MY_MIN(args[0]->decimal_scale() + args[1]->decimal_scale(),
+                   DECIMAL_MAX_SCALE);
+  uint est_prec = args[0]->decimal_precision() + args[1]->decimal_precision();
+  uint precision= MY_MIN(est_prec, DECIMAL_MAX_PRECISION);
+  max_length= my_decimal_precision_to_length_no_truncation(precision, decimals,
+                                                           unsigned_flag);
+}
+
+
+bool Item_func_mul::fix_length_and_dec(THD *thd)
+{
+  DBUG_ENTER("Item_func_mul::fix_length_and_dec");
+  DBUG_PRINT("info", ("name %s", func_name()));
+  const Type_aggregator *aggregator= &type_handler_data->m_type_aggregator_for_mul;
+  DBUG_EXECUTE_IF("num_op", aggregator= &type_handler_data->m_type_aggregator_for_result;);
+  DBUG_ASSERT(aggregator->is_commutative());
+  if (fix_type_handler(aggregator))
+    DBUG_RETURN(TRUE);
+  if (Item_func_mul::type_handler()->Item_func_mul_fix_length_and_dec(this))
+    DBUG_RETURN(TRUE);
+  DBUG_PRINT("info", ("Type: %s", type_handler()->name().ptr()));
+  DBUG_RETURN(FALSE);
+}
+
+
+double Item_func_div::real_op()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  double val2= args[1]->val_real();
+  if ((null_value= args[0]->null_value || args[1]->null_value))
+    return 0.0;
+  if (val2 == 0.0)
+  {
+    signal_divide_by_null();
+    return 0.0;
+  }
+  return check_float_overflow(value/val2);
+}
+
+
+my_decimal *Item_func_div::decimal_op(my_decimal *decimal_value)
+{
+  int err;
+  VDec2_lazy val(args[0], args[1]);
+  if ((null_value= val.has_null()))
+    return 0;
+  if ((err= check_decimal_overflow(my_decimal_div(E_DEC_FATAL_ERROR &
+                                                  ~E_DEC_OVERFLOW &
+                                                  ~E_DEC_DIV_ZERO,
+                                                  decimal_value,
+                                                  val.m_a.ptr(), val.m_b.ptr(),
+                                                  prec_increment))) > 3)
+  {
+    if (err == E_DEC_DIV_ZERO)
+      signal_divide_by_null();
+    null_value= 1;
+    return 0;
+  }
+  return decimal_value;
+}
+
+
+void Item_func_div::result_precision()
+{
+  /*
+    We need to add args[1]->divisor_precision_increment(),
+    to properly handle the cases like this:
+      SELECT 5.05 / 0.014; -> 360.714286
+    i.e. when the divisor has a zero integer part
+    and non-zero digits appear only after the decimal point.
+    Precision in this example is calculated as
+      args[0]->decimal_precision()           +  // 3
+      args[1]->divisor_precision_increment() +  // 3
+      prec_increment                            // 4
+    which gives 10 decimals digits.
+  */
+  uint precision=MY_MIN(args[0]->decimal_precision() + 
+                     args[1]->divisor_precision_increment() + prec_increment,
+                     DECIMAL_MAX_PRECISION);
+  decimals= MY_MIN(args[0]->decimal_scale() + prec_increment, DECIMAL_MAX_SCALE);
+  max_length= my_decimal_precision_to_length_no_truncation(precision, decimals,
+                                                           unsigned_flag);
+}
+
+
+void Item_func_div::fix_length_and_dec_double(void)
+{
+  Item_num_op::fix_length_and_dec_double();
+  decimals= MY_MAX(args[0]->decimals, args[1]->decimals) + prec_increment;
+  set_if_smaller(decimals, NOT_FIXED_DEC);
+  uint tmp= float_length(decimals);
+  if (decimals == NOT_FIXED_DEC)
+    max_length= tmp;
+  else
+  {
+    max_length=args[0]->max_length - args[0]->decimals + decimals;
+    set_if_smaller(max_length, tmp);
+  }
+}
+
+
+void Item_func_div::fix_length_and_dec_int(void)
+{
+  set_handler(&type_handler_newdecimal);
+  DBUG_PRINT("info", ("Type changed: %s", type_handler()->name().ptr()));
+  Item_num_op::fix_length_and_dec_decimal();
+}
+
+
+bool Item_func_div::fix_length_and_dec(THD *thd)
+{
+  DBUG_ENTER("Item_func_div::fix_length_and_dec");
+  DBUG_PRINT("info", ("name %s", func_name()));
+  prec_increment= thd->variables.div_precincrement;
+  set_maybe_null(); // division by zero
+
+  const Type_aggregator *aggregator= &type_handler_data->m_type_aggregator_for_div;
+  DBUG_EXECUTE_IF("num_op", aggregator= &type_handler_data->m_type_aggregator_non_commutative_test;);
+  DBUG_ASSERT(!aggregator->is_commutative());
+  if (fix_type_handler(aggregator))
+    DBUG_RETURN(TRUE);
+  if (Item_func_div::type_handler()->Item_func_div_fix_length_and_dec(this))
+    DBUG_RETURN(TRUE);
+  DBUG_PRINT("info", ("Type: %s", type_handler()->name().ptr()));
+  DBUG_RETURN(FALSE);
+}
+
+
+/* Integer division */
+longlong Item_func_int_div::val_int()
+{
+  DBUG_ASSERT(fixed());
+
+  /*
+    Perform division using DECIMAL math if either of the operands has a
+    non-integer type
+  */
+  if (args[0]->result_type() != INT_RESULT ||
+      args[1]->result_type() != INT_RESULT)
+  {
+    VDec2_lazy val(args[0], args[1]);
+    if ((null_value= val.has_null()))
+      return 0;
+
+    int err;
+    my_decimal tmp;
+    if ((err= my_decimal_div(E_DEC_FATAL_ERROR & ~E_DEC_DIV_ZERO, &tmp,
+                             val.m_a.ptr(), val.m_b.ptr(), 0)) > 3)
+    {
+      if (err == E_DEC_DIV_ZERO)
+        signal_divide_by_null();
+      return 0;
+    }
+
+    my_decimal truncated;
+    if (tmp.round_to(&truncated, 0, TRUNCATE))
+      DBUG_ASSERT(false);
+
+    longlong res;
+    if (my_decimal2int(E_DEC_FATAL_ERROR, &truncated, unsigned_flag, &res) &
+        E_DEC_OVERFLOW)
+      raise_integer_overflow();
+    return res;
+  }
+
+  Longlong_hybrid val0= args[0]->to_longlong_hybrid();
+  Longlong_hybrid val1= args[1]->to_longlong_hybrid();
+  if ((null_value= (args[0]->null_value || args[1]->null_value)))
+    return 0;
+  if (val1 == 0)
+  {
+    signal_divide_by_null();
+    return 0;
+  }
+
+  return check_integer_overflow(ULonglong_hybrid(val0.abs() / val1.abs(),
+                                                 val0.neg() != val1.neg()));
+}
+
+
+bool Item_func_int_div::fix_length_and_dec(THD *thd)
+{
+  uint32 prec= args[0]->decimal_int_part();
+  set_if_smaller(prec, MY_INT64_NUM_DECIMAL_DIGITS);
+  fix_char_length(prec);
+  set_maybe_null();
+  unsigned_flag=args[0]->unsigned_flag | args[1]->unsigned_flag;
+  return false;
+}
+
+
+longlong Item_func_mod::int_op()
+{
+  DBUG_ASSERT(fixed());
+  Longlong_hybrid val0= args[0]->to_longlong_hybrid();
+  Longlong_hybrid val1= args[1]->to_longlong_hybrid();
+
+  if ((null_value= args[0]->null_value || args[1]->null_value))
+    return 0; /* purecov: inspected */
+  if (val1 == 0)
+  {
+    signal_divide_by_null();
+    return 0;
+  }
+
+  /*
+    '%' is calculated by integer division internally. Since dividing
+    LONGLONG_MIN by -1 generates SIGFPE, we calculate using unsigned values and
+    then adjust the sign appropriately.
+  */
+  return check_integer_overflow(ULonglong_hybrid(val0.abs() % val1.abs(),
+                                                 val0.neg()));
+}
+
+double Item_func_mod::real_op()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  double val2=  args[1]->val_real();
+  if ((null_value= args[0]->null_value || args[1]->null_value))
+    return 0.0; /* purecov: inspected */
+  if (val2 == 0.0)
+  {
+    signal_divide_by_null();
+    return 0.0;
+  }
+  return fmod(value,val2);
+}
+
+
+my_decimal *Item_func_mod::decimal_op(my_decimal *decimal_value)
+{
+  VDec2_lazy val(args[0], args[1]);
+  if ((null_value= val.has_null()))
+    return 0;
+  switch (my_decimal_mod(E_DEC_FATAL_ERROR & ~E_DEC_DIV_ZERO, decimal_value,
+                         val.m_a.ptr(), val.m_b.ptr())) {
+  case E_DEC_TRUNCATED:
+  case E_DEC_OK:
+    return decimal_value;
+  case E_DEC_DIV_ZERO:
+    signal_divide_by_null();
+    /* fall through */
+  default:
+    null_value= 1;
+    return 0;
+  }
+}
+
+
+void Item_func_mod::result_precision()
+{
+  unsigned_flag= args[0]->unsigned_flag;
+  decimals= MY_MAX(args[0]->decimal_scale(), args[1]->decimal_scale());
+  uint prec= MY_MAX(args[0]->decimal_precision(), args[1]->decimal_precision());
+  fix_char_length(my_decimal_precision_to_length_no_truncation(prec, decimals,
+                                                               unsigned_flag));
+}
+
+
+bool Item_func_mod::fix_length_and_dec(THD *thd)
+{
+  DBUG_ENTER("Item_func_mod::fix_length_and_dec");
+  DBUG_PRINT("info", ("name %s", func_name()));
+  set_maybe_null(); // division by zero
+  const Type_aggregator *aggregator= &type_handler_data->m_type_aggregator_for_mod;
+  DBUG_EXECUTE_IF("num_op", aggregator= &type_handler_data->m_type_aggregator_non_commutative_test;);
+  DBUG_ASSERT(!aggregator->is_commutative());
+  if (fix_type_handler(aggregator))
+    DBUG_RETURN(TRUE);
+  if (Item_func_mod::type_handler()->Item_func_mod_fix_length_and_dec(this))
+    DBUG_RETURN(TRUE);
+  DBUG_PRINT("info", ("Type: %s", type_handler()->name().ptr()));
+  DBUG_RETURN(FALSE);
+}
+
+static void calc_hash_for_unique(ulong &nr1, ulong &nr2, String *str)
+{
+  CHARSET_INFO *cs;
+  uchar l[4];
+  int4store(l, str->length());
+  cs= str->charset();
+  cs->hash_sort(l, sizeof(l), &nr1, &nr2);
+  cs= str->charset();
+  cs->hash_sort((uchar *)str->ptr(), str->length(), &nr1, &nr2);
+}
+
+longlong  Item_func_hash_mariadb_100403::val_int()
+{
+  DBUG_EXECUTE_IF("same_long_unique_hash", return 9;);
+  unsigned_flag= true;
+  ulong nr1= 1,nr2= 4;
+  String * str;
+  for(uint i= 0;i<arg_count;i++)
+  {
+    str = args[i]->val_str();
+    if(args[i]->null_value)
+    {
+      null_value= 1;
+      return 0;
+    }
+   calc_hash_for_unique(nr1, nr2, str);
+  }
+  null_value= 0;
+  return   (longlong)nr1;
+}
+
+
+longlong  Item_func_hash::val_int()
+{
+  DBUG_EXECUTE_IF("same_long_unique_hash", return 9;);
+  unsigned_flag= true;
+  Hasher hasher;
+  for(uint i= 0;i<arg_count;i++)
+  {
+    if (args[i]->hash_not_null(&hasher))
+    {
+      null_value= 1;
+      return 0;
+    }
+  }
+  null_value= 0;
+  return (longlong) hasher.finalize();
+}
+
+
+bool Item_func_hash::fix_length_and_dec(THD *thd)
+{
+  decimals= 0;
+  max_length= 8;
+  return false;
+}
+
+
+
+double Item_func_neg::real_op()
+{
+  double value= args[0]->val_real();
+  null_value= args[0]->null_value;
+  return -value;
+}
+
+
+longlong Item_func_neg::int_op()
+{
+  longlong value= args[0]->val_int();
+  if ((null_value= args[0]->null_value))
+    return 0;
+  if (args[0]->unsigned_flag &&
+      (ulonglong) value > (ulonglong) LONGLONG_MAX + 1)
+    return raise_integer_overflow();
+
+  if (value == LONGLONG_MIN)
+  {
+    if (args[0]->unsigned_flag != unsigned_flag)
+      /* negation of LONGLONG_MIN is LONGLONG_MIN. */
+      return LONGLONG_MIN; 
+    else
+      return raise_integer_overflow();
+  }
+
+  return check_integer_overflow(-value, !args[0]->unsigned_flag && value < 0);
+}
+
+
+my_decimal *Item_func_neg::decimal_op(my_decimal *decimal_value)
+{
+  VDec value(args[0]);
+  if (!(null_value= value.is_null()))
+  {
+    my_decimal2decimal(value.ptr(), decimal_value);
+    my_decimal_neg(decimal_value);
+    return decimal_value;
+  }
+  return 0;
+}
+
+
+void Item_func_neg::fix_length_and_dec_int()
+{
+  max_length= args[0]->max_length + 1;
+  set_handler(type_handler_long_or_longlong());
+
+  /*
+    If this is in integer context keep the context as integer if possible
+    (This is how multiplication and other integer functions works)
+    Use val() to get value as arg_type doesn't mean that item is
+    Item_int or Item_float due to existence of Item_param.
+  */
+  if (args[0]->const_item())
+  {
+    longlong val= args[0]->val_int();
+    if ((ulonglong) val >= (ulonglong) LONGLONG_MIN &&
+        ((ulonglong) val != (ulonglong) LONGLONG_MIN ||
+         !args[0]->is_of_type(CONST_ITEM, INT_RESULT)))
+    {
+      /*
+        Ensure that result is converted to DECIMAL, as longlong can't hold
+        the negated number
+      */
+      set_handler(&type_handler_newdecimal);
+      DBUG_PRINT("info", ("Type changed: DECIMAL_RESULT"));
+    }
+  }
+  unsigned_flag= false;
+}
+
+
+void Item_func_neg::fix_length_and_dec_double()
+{
+  set_handler(&type_handler_double);
+  decimals= args[0]->decimals; // Preserve NOT_FIXED_DEC
+  max_length= args[0]->max_length + 1;
+  // Limit length with something reasonable
+  uint32 mlen= type_handler()->max_display_length(this);
+  set_if_smaller(max_length, mlen);
+  unsigned_flag= false;
+}
+
+
+void Item_func_neg::fix_length_and_dec_decimal()
+{
+  set_handler(&type_handler_newdecimal);
+  decimals= args[0]->decimal_scale(); // Do not preserve NOT_FIXED_DEC
+  max_length= args[0]->max_length + 1;
+  unsigned_flag= false;
+}
+
+
+bool Item_func_neg::fix_length_and_dec(THD *thd)
+{
+  DBUG_ENTER("Item_func_neg::fix_length_and_dec");
+  DBUG_PRINT("info", ("name %s", func_name()));
+  if (args[0]->cast_to_int_type_handler()->
+      Item_func_neg_fix_length_and_dec(this))
+    DBUG_RETURN(TRUE);
+  DBUG_PRINT("info", ("Type: %s", type_handler()->name().ptr()));
+  DBUG_RETURN(FALSE);
+}
+
+
+double Item_func_abs::real_op()
+{
+  double value= args[0]->val_real();
+  null_value= args[0]->null_value;
+  return fabs(value);
+}
+
+
+longlong Item_func_abs::int_op()
+{
+  longlong value= args[0]->val_int();
+  if ((null_value= args[0]->null_value))
+    return 0;
+  if (unsigned_flag)
+    return value;
+  /* -LONGLONG_MIN = LONGLONG_MAX + 1 => outside of signed longlong range */
+  if (value == LONGLONG_MIN)
+    return raise_integer_overflow();
+  return (value >= 0) ? value : -value;
+}
+
+
+my_decimal *Item_func_abs::decimal_op(my_decimal *decimal_value)
+{
+  VDec value(args[0]);
+  if (!(null_value= value.is_null()))
+  {
+    my_decimal2decimal(value.ptr(), decimal_value);
+    if (decimal_value->sign())
+      my_decimal_neg(decimal_value);
+    return decimal_value;
+  }
+  return 0;
+}
+
+void Item_func_abs::fix_length_and_dec_int()
+{
+  max_length= args[0]->max_length;
+  unsigned_flag= args[0]->unsigned_flag;
+  set_handler(type_handler_long_or_longlong());
+}
+
+
+void Item_func_abs::fix_length_and_dec_double()
+{
+  set_handler(&type_handler_double);
+  decimals= args[0]->decimals; // Preserve NOT_FIXED_DEC
+  max_length= float_length(decimals);
+  unsigned_flag= args[0]->unsigned_flag;
+}
+
+
+void Item_func_abs::fix_length_and_dec_decimal()
+{
+  set_handler(&type_handler_newdecimal);
+  decimals= args[0]->decimal_scale(); // Do not preserve NOT_FIXED_DEC
+  max_length= args[0]->max_length;
+  unsigned_flag= args[0]->unsigned_flag;
+}
+
+
+bool Item_func_abs::fix_length_and_dec(THD *thd)
+{
+  DBUG_ENTER("Item_func_abs::fix_length_and_dec");
+  DBUG_PRINT("info", ("name %s", func_name()));
+  if (args[0]->cast_to_int_type_handler()->
+      Item_func_abs_fix_length_and_dec(this))
+    DBUG_RETURN(TRUE);
+  DBUG_PRINT("info", ("Type: %s", type_handler()->name().ptr()));
+  DBUG_RETURN(FALSE);
+}
+
+
+/** Gateway to natural LOG function. */
+double Item_func_ln::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  if ((null_value= args[0]->null_value))
+    return 0.0;
+  if (value <= 0.0)
+  {
+    signal_divide_by_null();
+    return 0.0;
+  }
+  return log(value);
+}
+
+/** 
+  Extended but so slower LOG function.
+
+  We have to check if all values are > zero and first one is not one
+  as these are the cases then result is not a number.
+*/ 
+double Item_func_log::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  if ((null_value= args[0]->null_value))
+    return 0.0;
+  if (value <= 0.0)
+  {
+    signal_divide_by_null();
+    return 0.0;
+  }
+  if (arg_count == 2)
+  {
+    double value2= args[1]->val_real();
+    if ((null_value= args[1]->null_value))
+      return 0.0;
+    if (value2 <= 0.0 || value == 1.0)
+    {
+      signal_divide_by_null();
+      return 0.0;
+    }
+    return log(value2) / log(value);
+  }
+  return log(value);
+}
+
+double Item_func_log2::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+
+  if ((null_value=args[0]->null_value))
+    return 0.0;
+  if (value <= 0.0)
+  {
+    signal_divide_by_null();
+    return 0.0;
+  }
+  return log(value) / M_LN2;
+}
+
+double Item_func_log10::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  if ((null_value= args[0]->null_value))
+    return 0.0;
+  if (value <= 0.0)
+  {
+    signal_divide_by_null();
+    return 0.0;
+  }
+  return log10(value);
+}
+
+double Item_func_exp::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  if ((null_value=args[0]->null_value))
+    return 0.0; /* purecov: inspected */
+  return check_float_overflow(exp(value));
+}
+
+double Item_func_sqrt::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  if ((null_value=(args[0]->null_value || value < 0)))
+    return 0.0; /* purecov: inspected */
+  return sqrt(value);
+}
+
+double Item_func_pow::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  double val2= args[1]->val_real();
+  if ((null_value=(args[0]->null_value || args[1]->null_value)))
+    return 0.0; /* purecov: inspected */
+  return check_float_overflow(pow(value,val2));
+}
+
+// Trigonometric functions
+
+double Item_func_acos::val_real()
+{
+  DBUG_ASSERT(fixed());
+  /* One can use this to defer SELECT processing. */
+  DEBUG_SYNC(current_thd, "before_acos_function");
+  // the volatile's for BUG #2338 to calm optimizer down (because of gcc's bug)
+  volatile double value= args[0]->val_real();
+  if ((null_value=(args[0]->null_value || (value < -1.0 || value > 1.0))))
+    return 0.0;
+  return acos(value);
+}
+
+double Item_func_asin::val_real()
+{
+  DBUG_ASSERT(fixed());
+  // the volatile's for BUG #2338 to calm optimizer down (because of gcc's bug)
+  volatile double value= args[0]->val_real();
+  if ((null_value=(args[0]->null_value || (value < -1.0 || value > 1.0))))
+    return 0.0;
+  return asin(value);
+}
+
+double Item_func_atan::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  if ((null_value=args[0]->null_value))
+    return 0.0;
+  if (arg_count == 2)
+  {
+    double val2= args[1]->val_real();
+    if ((null_value=args[1]->null_value))
+      return 0.0;
+    return check_float_overflow(atan2(value,val2));
+  }
+  return atan(value);
+}
+
+double Item_func_cos::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  if ((null_value=args[0]->null_value))
+    return 0.0;
+  return cos(value);
+}
+
+double Item_func_sin::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  if ((null_value=args[0]->null_value))
+    return 0.0;
+  return sin(value);
+}
+
+double Item_func_tan::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  if ((null_value=args[0]->null_value))
+    return 0.0;
+  return check_float_overflow(tan(value));
+}
+
+
+double Item_func_cot::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  if ((null_value=args[0]->null_value))
+    return 0.0;
+  return check_float_overflow(1.0 / tan(value));
+}
+
+
+// Shift-functions, same as << and >> in C/C++
+
+
+class Func_handler_shift_left_int_to_ulonglong:
+        public Item_handled_func::Handler_ulonglong
+{
+public:
+  Longlong_null to_longlong_null(Item_handled_func *item) const
+  {
+    DBUG_ASSERT(item->fixed());
+    return item->arguments()[0]->to_longlong_null() <<
+           item->arguments()[1]->to_longlong_null();
+  }
+};
+
+
+class Func_handler_shift_left_decimal_to_ulonglong:
+        public Item_handled_func::Handler_ulonglong
+{
+public:
+  Longlong_null to_longlong_null(Item_handled_func *item) const
+  {
+    DBUG_ASSERT(item->fixed());
+    return VDec(item->arguments()[0]).to_xlonglong_null() <<
+           item->arguments()[1]->to_longlong_null();
+  }
+};
+
+
+bool Item_func_shift_left::fix_length_and_dec(THD *thd)
+{
+  static Func_handler_shift_left_int_to_ulonglong ha_int_to_ull;
+  static Func_handler_shift_left_decimal_to_ulonglong ha_dec_to_ull;
+  return fix_length_and_dec_op1_std(&ha_int_to_ull, &ha_dec_to_ull);
+}
+
+
+class Func_handler_shift_right_int_to_ulonglong:
+        public Item_handled_func::Handler_ulonglong
+{
+public:
+  Longlong_null to_longlong_null(Item_handled_func *item) const
+  {
+    DBUG_ASSERT(item->fixed());
+    return item->arguments()[0]->to_longlong_null() >>
+           item->arguments()[1]->to_longlong_null();
+  }
+};
+
+
+class Func_handler_shift_right_decimal_to_ulonglong:
+        public Item_handled_func::Handler_ulonglong
+{
+public:
+  Longlong_null to_longlong_null(Item_handled_func *item) const
+  {
+    DBUG_ASSERT(item->fixed());
+    return VDec(item->arguments()[0]).to_xlonglong_null() >>
+           item->arguments()[1]->to_longlong_null();
+  }
+};
+
+
+bool Item_func_shift_right::fix_length_and_dec(THD *thd)
+{
+  static Func_handler_shift_right_int_to_ulonglong ha_int_to_ull;
+  static Func_handler_shift_right_decimal_to_ulonglong ha_dec_to_ull;
+  return fix_length_and_dec_op1_std(&ha_int_to_ull, &ha_dec_to_ull);
+}
+
+
+class Func_handler_bit_neg_int_to_ulonglong:
+        public Item_handled_func::Handler_ulonglong
+{
+public:
+  Longlong_null to_longlong_null(Item_handled_func *item) const
+  {
+    DBUG_ASSERT(item->fixed());
+    return ~ item->arguments()[0]->to_longlong_null();
+  }
+};
+
+
+class Func_handler_bit_neg_decimal_to_ulonglong:
+        public Item_handled_func::Handler_ulonglong
+{
+public:
+  Longlong_null to_longlong_null(Item_handled_func *item) const
+  {
+    DBUG_ASSERT(item->fixed());
+    return ~ VDec(item->arguments()[0]).to_xlonglong_null();
+  }
+};
+
+
+bool Item_func_bit_neg::fix_length_and_dec(THD *thd)
+{
+  static Func_handler_bit_neg_int_to_ulonglong ha_int_to_ull;
+  static Func_handler_bit_neg_decimal_to_ulonglong ha_dec_to_ull;
+  return fix_length_and_dec_op1_std(&ha_int_to_ull, &ha_dec_to_ull);
+}
+
+
+// Conversion functions
+
+void Item_func_int_val::fix_length_and_dec_int_or_decimal()
+{
+  DBUG_ASSERT(args[0]->cmp_type() == DECIMAL_RESULT);
+  DBUG_ASSERT(args[0]->max_length <= DECIMAL_MAX_STR_LENGTH);
+  /*
+    FLOOR() for negative numbers can increase length:   floor(-9.9) -> -10
+    CEILING() for positive numbers can increase length:  ceil(9.9)  -> 10
+  */
+  decimal_round_mode mode= round_mode();
+  uint length_increase= args[0]->decimals > 0 &&
+                        (mode == CEILING ||
+                         (mode == FLOOR && !args[0]->unsigned_flag)) ? 1 : 0;
+  uint precision= args[0]->decimal_int_part() + length_increase;
+  set_if_bigger(precision, 1);
+
+  /*
+    The BIGINT data type can store:
+    UNSIGNED BIGINT: 0..18446744073709551615                     - up to 19 digits
+      SIGNED BIGINT:   -9223372036854775808..9223372036854775807 - up to 18 digits
+
+    The INT data type can store:
+        UNSIGNED INT:  0..4294967295          - up to 9 digits
+          SIGNED INT: -2147483648..2147483647 - up to 9 digits
+  */
+  if (precision > 18)
+  {
+    unsigned_flag= args[0]->unsigned_flag;
+    fix_char_length(
+      my_decimal_precision_to_length_no_truncation(precision, 0,
+                                                   unsigned_flag));
+    set_handler(&type_handler_newdecimal);
+  }
+  else
+  {
+    uint sign_length= (unsigned_flag= args[0]->unsigned_flag) ? 0 : 1;
+    fix_char_length(precision + sign_length);
+    if (precision > 9)
+    {
+      if (unsigned_flag)
+        set_handler(&type_handler_ulonglong);
+      else
+        set_handler(&type_handler_slonglong);
+    }
+    else
+    {
+      if (unsigned_flag)
+        set_handler(&type_handler_ulong);
+      else
+        set_handler(&type_handler_slong);
+    }
+  }
+}
+
+
+void Item_func_int_val::fix_length_and_dec_double()
+{
+  set_handler(&type_handler_double);
+  max_length= float_length(0);
+  decimals= 0;
+}
+
+
+bool Item_func_int_val::fix_length_and_dec(THD *thd)
+{
+  DBUG_ENTER("Item_func_int_val::fix_length_and_dec");
+  DBUG_PRINT("info", ("name %s", func_name()));
+  /*
+    We don't want to translate ENUM/SET to CHAR here.
+    So let's call real_type_handler(), not type_handler().
+  */
+  if (args[0]->real_type_handler()->Item_func_int_val_fix_length_and_dec(this))
+    DBUG_RETURN(TRUE);
+  DBUG_PRINT("info", ("Type: %s", real_type_handler()->name().ptr()));
+  DBUG_RETURN(FALSE);
+}
+
+
+bool Item_func_int_val::native_op(THD *thd, Native *to)
+{
+  // TODO: turn Item_func_int_val into Item_handled_func eventually.
+  if (type_handler()->mysql_timestamp_type() == MYSQL_TIMESTAMP_TIME)
+    return Time(thd, this).to_native(to, decimals);
+  DBUG_ASSERT(0);
+  return true;
+}
+
+
+longlong Item_func_ceiling::int_op()
+{
+  switch (args[0]->result_type()) {
+  case STRING_RESULT: // hex hybrid
+  case INT_RESULT:
+    return val_int_from_item(args[0]);
+  case DECIMAL_RESULT:
+    return VDec_op(this).to_longlong(unsigned_flag);
+  default:
+    break;
+  }
+  return (longlong) Item_func_ceiling::real_op();
+}
+
+
+double Item_func_ceiling::real_op()
+{
+  /*
+    the volatile's for BUG #3051 to calm optimizer down (because of gcc's
+    bug)
+  */
+  volatile double value= args[0]->val_real();
+  null_value= args[0]->null_value;
+  return ceil(value);
+}
+
+
+my_decimal *Item_func_ceiling::decimal_op(my_decimal *decimal_value)
+{
+  VDec value(args[0]);
+  if (!(null_value= (value.is_null() ||
+                     value.round_to(decimal_value, 0, CEILING) > 1)))
+    return decimal_value;
+  return 0;
+}
+
+
+bool Item_func_ceiling::date_op(THD *thd, MYSQL_TIME *to,
+                                date_mode_t fuzzydate)
+{
+  Datetime::Options opt(thd, TIME_FRAC_TRUNCATE);
+  Datetime *tm= new (to) Datetime(thd, args[0], opt);
+  tm->ceiling(thd);
+  null_value= !tm->is_valid_datetime();
+  DBUG_ASSERT(maybe_null() || !null_value);
+  return null_value;
+}
+
+
+bool Item_func_ceiling::time_op(THD *thd, MYSQL_TIME *to)
+{
+  static const Time::Options_for_round opt;
+  Time *tm= new (to) Time(thd, args[0], opt);
+  tm->ceiling();
+  null_value= !tm->is_valid_time();
+  DBUG_ASSERT(maybe_null() || !null_value);
+  return null_value;
+}
+
+
+longlong Item_func_floor::int_op()
+{
+  switch (args[0]->result_type()) {
+  case STRING_RESULT: // hex hybrid
+  case INT_RESULT:
+    return val_int_from_item(args[0]);
+  case DECIMAL_RESULT:
+  {
+    my_decimal dec_buf, *dec;
+    return (!(dec= Item_func_floor::decimal_op(&dec_buf))) ? 0 :
+           dec->to_longlong(unsigned_flag);
+  }
+  default:
+    break;
+  }
+  return (longlong) Item_func_floor::real_op();
+}
+
+
+double Item_func_floor::real_op()
+{
+  /*
+    the volatile's for BUG #3051 to calm optimizer down (because of gcc's
+    bug)
+  */
+  volatile double value= args[0]->val_real();
+  null_value= args[0]->null_value;
+  return floor(value);
+}
+
+
+my_decimal *Item_func_floor::decimal_op(my_decimal *decimal_value)
+{
+  VDec value(args[0]);
+  if (!(null_value= (value.is_null() ||
+                     value.round_to(decimal_value, 0, FLOOR) > 1)))
+    return decimal_value;
+  return 0;
+}
+
+
+bool Item_func_floor::date_op(THD *thd, MYSQL_TIME *to, date_mode_t fuzzydate)
+{
+  // DATETIME is not negative, so FLOOR means just truncation
+  Datetime::Options opt(thd, TIME_FRAC_TRUNCATE);
+  Datetime *tm= new (to) Datetime(thd, args[0], opt, 0);
+  null_value= !tm->is_valid_datetime();
+  DBUG_ASSERT(maybe_null() || !null_value);
+  return null_value;
+}
+
+
+bool Item_func_floor::time_op(THD *thd, MYSQL_TIME *to)
+{
+  static const Time::Options_for_round opt;
+  Time *tm= new (to) Time(thd, args[0], opt);
+  tm->floor();
+  null_value= !tm->is_valid_time();
+  DBUG_ASSERT(maybe_null() || !null_value);
+  return null_value;
+}
+
+
+void Item_func_round::fix_length_and_dec_decimal(uint decimals_to_set)
+{
+  int decimals_delta= args[0]->decimals - decimals_to_set;
+  int length_increase= (decimals_delta <= 0 || truncate) ? 0 : 1;
+  int precision= args[0]->decimal_precision() + length_increase -
+                                                decimals_delta;
+  DBUG_ASSERT(decimals_to_set <= DECIMAL_MAX_SCALE);
+  set_handler(&type_handler_newdecimal);
+  unsigned_flag= args[0]->unsigned_flag;
+  decimals= decimals_to_set;
+  if (!precision)
+    precision= 1; // DECIMAL(0,0) -> DECIMAL(1,0)
+  max_length= my_decimal_precision_to_length_no_truncation(precision,
+                                                           decimals,
+                                                           unsigned_flag);
+}
+
+void Item_func_round::fix_length_and_dec_double(uint decimals_to_set)
+{
+  set_handler(&type_handler_double);
+  unsigned_flag= args[0]->unsigned_flag;
+  decimals= decimals_to_set;
+  max_length= float_length(decimals_to_set);
+}
+
+
+void Item_func_round::fix_arg_decimal()
+{
+  if (args[1]->const_item())
+  {
+    Longlong_hybrid dec= args[1]->to_longlong_hybrid();
+    if (args[1]->null_value)
+      fix_length_and_dec_double(NOT_FIXED_DEC);
+    else
+      fix_length_and_dec_decimal(dec.to_uint(DECIMAL_MAX_SCALE));
+  }
+  else
+  {
+    set_handler(&type_handler_newdecimal);
+    unsigned_flag= args[0]->unsigned_flag;
+    decimals= args[0]->decimals;
+    max_length= args[0]->max_length;
+  }
+}
+
+
+void Item_func_round::fix_arg_double()
+{
+  if (args[1]->const_item())
+  {
+    Longlong_hybrid dec= args[1]->to_longlong_hybrid();
+    fix_length_and_dec_double(args[1]->null_value ? NOT_FIXED_DEC :
+                              dec.to_uint(NOT_FIXED_DEC));
+  }
+  else
+    fix_length_and_dec_double(args[0]->decimals);
+}
+
+
+void Item_func_round::fix_arg_temporal(const Type_handler *h,
+                                       uint int_part_length)
+{
+  set_handler(h);
+  if (args[1]->can_eval_in_optimize())
+  {
+    Longlong_hybrid_null dec= args[1]->to_longlong_hybrid_null();
+    fix_attributes_temporal(int_part_length,
+                            dec.is_null() ? args[0]->decimals :
+                            dec.to_uint(TIME_SECOND_PART_DIGITS));
+  }
+  else
+    fix_attributes_temporal(int_part_length, args[0]->decimals);
+}
+
+
+void Item_func_round::fix_arg_time()
+{
+  fix_arg_temporal(&type_handler_time2, MIN_TIME_WIDTH);
+}
+
+
+void Item_func_round::fix_arg_datetime()
+{
+  /*
+    Day increment operations are not supported for '0000-00-00',
+    see get_date_from_daynr() for details. Therefore, expressions like
+      ROUND('0000-00-00 23:59:59.999999')
+    return NULL.
+  */
+  if (!truncate)
+    set_maybe_null();
+  fix_arg_temporal(&type_handler_datetime2, MAX_DATETIME_WIDTH);
+}
+
+
+bool Item_func_round::test_if_length_can_increase()
+{
+  if (truncate)
+    return false;
+  if (args[1]->can_eval_in_optimize())
+  {
+    // Length can increase in some cases: e.g. ROUND(9,-1) -> 10.
+    Longlong_hybrid val1= args[1]->to_longlong_hybrid();
+    return !args[1]->null_value && val1.neg();
+  }
+  return true; // ROUND(x,n), where n is not a constant.
+}
+
+
+/**
+  Calculate data type and attributes for INT-alike input.
+
+  @param [IN] preferred - The preferred data type handler for simple cases
+                          such as ROUND(x) and TRUNCATE(x,0), when the input
+                          is short enough to fit into an integer type
+                          (without extending to DECIMAL).
+                          - If `preferred` is not NULL, then the code tries
+                            to preserve the given data type handler and
+                            the data type attributes `preferred_attrs`.
+                          - If `preferred` is NULL, then the code fully
+                            calculates attributes using
+                            args[0]->decimal_precision() and chooses between
+                            INT and BIGINT, depending on attributes.
+  @param [IN] preferred_attrs - The preferred data type attributes for
+                                simple cases.
+*/
+void Item_func_round::fix_arg_int(const Type_handler *preferred,
+                                  const Type_std_attributes *preferred_attrs,
+                                  bool use_decimal_on_length_increase)
+{
+  DBUG_ASSERT(args[0]->decimals == 0);
+
+  Type_std_attributes::set(preferred_attrs);
+  if (!test_if_length_can_increase())
+  {
+    // Preserve the exact data type and attributes
+    set_handler(preferred);
+  }
+  else
+  {
+    max_length++;
+    if (use_decimal_on_length_increase)
+      set_handler(&type_handler_newdecimal);
+    else
+      set_handler(type_handler_long_or_longlong());
+  }
+}
+
+
+void Item_func_round::fix_arg_hex_hybrid()
+{
+  DBUG_ASSERT(args[0]->decimals == 0);
+  DBUG_ASSERT(args[0]->decimal_precision() < DECIMAL_LONGLONG_DIGITS);
+  DBUG_ASSERT(args[0]->unsigned_flag); // no needs to add sign length
+  bool length_can_increase= test_if_length_can_increase();
+  max_length= args[0]->decimal_precision() + MY_TEST(length_can_increase);
+  unsigned_flag= true;
+  decimals= 0;
+  if (length_can_increase && args[0]->max_length >= 8)
+    set_handler(&type_handler_newdecimal);
+  else
+    set_handler(type_handler_long_or_longlong());
+}
+
+
+double my_double_round(double value, longlong dec, bool dec_unsigned,
+                       bool truncate)
+{
+  double tmp;
+  bool dec_negative= (dec < 0) && !dec_unsigned;
+  ulonglong abs_dec= dec_negative ? -dec : dec;
+  /*
+    tmp2 is here to avoid return the value with 80 bit precision
+    This will fix that the test round(0.1,1) = round(0.1,1) is true
+    Tagging with volatile is no guarantee, it may still be optimized away...
+  */
+  volatile double tmp2;
+
+  tmp=(abs_dec < array_elements(log_10) ?
+       log_10[abs_dec] : pow(10.0,(double) abs_dec));
+
+  // Pre-compute these, to avoid optimizing away e.g. 'floor(v/tmp) * tmp'.
+  volatile double value_div_tmp= value / tmp;
+  volatile double value_mul_tmp= value * tmp;
+
+  if (!dec_negative && std::isinf(tmp)) // "dec" is too large positive number
+    return value;
+
+  if (dec_negative && std::isinf(tmp))
+    tmp2= 0.0;
+  else if (!dec_negative && std::isinf(value_mul_tmp))
+    tmp2= value;
+  else if (truncate)
+  {
+    if (value >= 0.0)
+      tmp2= dec < 0 ? floor(value_div_tmp) * tmp : floor(value_mul_tmp) / tmp;
+    else
+      tmp2= dec < 0 ? ceil(value_div_tmp) * tmp : ceil(value_mul_tmp) / tmp;
+  }
+  else
+    tmp2=dec < 0 ? rint(value_div_tmp) * tmp : rint(value_mul_tmp) / tmp;
+
+  return tmp2;
+}
+
+
+double Item_func_round::real_op()
+{
+  double value= args[0]->val_real();
+
+  if (!(null_value= args[0]->null_value))
+  {
+    longlong dec= args[1]->val_int();
+    if (!(null_value= args[1]->null_value))
+      return my_double_round(value, dec, args[1]->unsigned_flag, truncate);
+  }
+  return 0.0;
+}
+
+/*
+  Rounds a given value to a power of 10 specified as the 'to' argument,
+  avoiding overflows when the value is close to the ulonglong range boundary.
+*/
+
+static inline ulonglong my_unsigned_round(ulonglong value, ulonglong to)
+{
+  ulonglong tmp= value / to * to;
+  return (value - tmp < (to >> 1)) ? tmp : tmp + to;
+}
+
+
+longlong Item_func_round::int_op()
+{
+  longlong value= args[0]->val_int();
+  longlong dec= args[1]->val_int();
+  decimals= 0;
+  ulonglong abs_dec;
+  if ((null_value= args[0]->null_value || args[1]->null_value))
+    return 0;
+  if ((dec >= 0) || args[1]->unsigned_flag)
+    return value; // integer have not digits after point
+
+  abs_dec= Longlong(dec).abs(); // Avoid undefined behavior
+  longlong tmp;
+  
+  if(abs_dec >= array_elements(log_10_int))
+    return 0;
+  
+  tmp= log_10_int[abs_dec];
+  
+  if (truncate)
+    value= (unsigned_flag) ?
+      ((ulonglong) value / tmp) * tmp : (value / tmp) * tmp;
+  else
+    value= (unsigned_flag || value >= 0) ?
+      my_unsigned_round((ulonglong) value, tmp) :
+      -(longlong) my_unsigned_round((ulonglong) -value, tmp);
+  return value;
+}
+
+
+my_decimal *Item_func_round::decimal_op(my_decimal *decimal_value)
+{
+  VDec value(args[0]);
+  longlong dec= args[1]->val_int();
+  if (dec >= 0 || args[1]->unsigned_flag)
+    dec= MY_MIN((ulonglong) dec, decimals);
+  else if (dec < INT_MIN)
+    dec= INT_MIN;
+    
+  if (!(null_value= (value.is_null() || args[1]->null_value ||
+                     value.round_to(decimal_value, (int) dec,
+                                    truncate ? TRUNCATE : HALF_UP) > 1)))
+    return decimal_value;
+  return 0;
+}
+
+
+bool Item_func_round::time_op(THD *thd, MYSQL_TIME *to)
+{
+  DBUG_ASSERT(args[0]->type_handler()->mysql_timestamp_type() ==
+              MYSQL_TIMESTAMP_TIME);
+  Time::Options_for_round opt(truncate ? TIME_FRAC_TRUNCATE : TIME_FRAC_ROUND);
+  Longlong_hybrid_null dec= args[1]->to_longlong_hybrid_null();
+  Time *tm= new (to) Time(thd, args[0], opt,
+                          dec.to_uint(TIME_SECOND_PART_DIGITS));
+  null_value= !tm->is_valid_time() || dec.is_null();
+  DBUG_ASSERT(maybe_null() || !null_value);
+  return null_value;
+}
+
+
+bool Item_func_round::date_op(THD *thd, MYSQL_TIME *to, date_mode_t fuzzydate)
+{
+  DBUG_ASSERT(args[0]->type_handler()->mysql_timestamp_type() ==
+              MYSQL_TIMESTAMP_DATETIME);
+  Datetime::Options opt(thd, truncate ? TIME_FRAC_TRUNCATE : TIME_FRAC_ROUND);
+  Longlong_hybrid_null dec= args[1]->to_longlong_hybrid_null();
+  Datetime *tm= new (to) Datetime(thd, args[0], opt,
+                                  dec.to_uint(TIME_SECOND_PART_DIGITS));
+  null_value= !tm->is_valid_datetime() || dec.is_null();
+  DBUG_ASSERT(maybe_null() || !null_value);
+  return null_value;
+}
+
+
+bool Item_func_round::native_op(THD *thd, Native *to)
+{
+  // TODO: turn Item_func_round into Item_handled_func eventually.
+  if (type_handler()->mysql_timestamp_type() == MYSQL_TIMESTAMP_TIME)
+    return Time(thd, this).to_native(to, decimals);
+  DBUG_ASSERT(0);
+  return true;
+}
+
+
+void Item_func_rand::seed_random(Item *arg)
+{
+  /*
+    TODO: do not do reinit 'rand' for every execute of PS/SP if
+    args[0] is a constant.
+  */
+  uint32 tmp= (uint32) arg->val_int();
+#ifdef WITH_WSREP
+  if (WSREP_ON)
+  {
+    THD *thd= current_thd;
+    if (WSREP(thd))
+    {
+      if (wsrep_thd_is_applying(thd))
+        tmp= thd->wsrep_rand;
+      else
+        thd->wsrep_rand= tmp;
+    }
+  }
+#endif /* WITH_WSREP */
+
+  my_rnd_init(rand, (uint32) (tmp*0x10001L+55555555L),
+             (uint32) (tmp*0x10000001L));
+}
+
+
+bool Item_func_rand::fix_fields(THD *thd,Item **ref)
+{
+  if (Item_real_func::fix_fields(thd, ref))
+    return TRUE;
+  used_tables_cache|= RAND_TABLE_BIT;
+  if (arg_count)
+  {					// Only use argument once in query
+    /*
+      Allocate rand structure once: we must use thd->stmt_arena
+      to create rand in proper mem_root if it's a prepared statement or
+      stored procedure.
+
+      No need to send a Rand log event if seed was given eg: RAND(seed),
+      as it will be replicated in the query as such.
+    */
+    if (!rand && !(rand= (struct my_rnd_struct*)
+                   thd->stmt_arena->alloc(sizeof(*rand))))
+      return TRUE;
+  }
+  else
+  {
+    /*
+      Save the seed only the first time RAND() is used in the query
+      Once events are forwarded rather than recreated,
+      the following can be skipped if inside the slave thread
+    */
+    if (!(thd->used & THD::RAND_USED))
+    {
+      thd->used|= THD::RAND_USED;
+      thd->rand_saved_seed1= thd->rand.seed1;
+      thd->rand_saved_seed2= thd->rand.seed2;
+    }
+    rand= &thd->rand;
+  }
+  return FALSE;
+}
+
+void Item_func_rand::update_used_tables()
+{
+  Item_real_func::update_used_tables();
+  used_tables_cache|= RAND_TABLE_BIT;
+}
+
+
+double Item_func_rand::val_real()
+{
+  DBUG_ASSERT(fixed());
+  if (arg_count)
+  {
+    if (!args[0]->const_item())
+      seed_random(args[0]);
+    else if (first_eval)
+    {
+      /*
+        Constantness of args[0] may be set during JOIN::optimize(), if arg[0]
+        is a field item of "constant" table. Thus, we have to evaluate
+        seed_random() for constant arg there but not at the fix_fields method.
+      */
+      first_eval= FALSE;
+      seed_random(args[0]);
+    }
+  }
+  return my_rnd(rand);
+}
+
+longlong Item_func_sign::val_int()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  null_value=args[0]->null_value;
+  return value < 0.0 ? -1 : (value > 0 ? 1 : 0);
+}
+
+
+double Item_func_units::val_real()
+{
+  DBUG_ASSERT(fixed());
+  double value= args[0]->val_real();
+  if ((null_value=args[0]->null_value))
+    return 0;
+  return check_float_overflow(value * mul + add);
+}
+
+
+bool Item_func_min_max::fix_attributes(Item **items, uint nitems)
+{
+  bool rc= Item_func_min_max::type_handler()->
+             Item_func_min_max_fix_attributes(current_thd, this, items, nitems);
+  DBUG_ASSERT(!rc || current_thd->is_error());
+  return rc;
+}
+
+
+/*
+  Compare item arguments using DATETIME/DATE/TIME representation.
+
+  DESCRIPTION
+    Compare item arguments as DATETIME values and return the index of the
+    least/greatest argument in the arguments array.
+    The correct DATE/DATETIME value of the found argument is
+    stored to the value pointer, if latter is provided.
+
+  RETURN
+   1	If one of arguments is NULL or there was a execution error
+   0    Otherwise
+*/
+
+bool Item_func_min_max::get_date_native(THD *thd, MYSQL_TIME *ltime,
+                                        date_mode_t fuzzydate)
+{
+  longlong UNINIT_VAR(min_max);
+  DBUG_ASSERT(fixed());
+
+  for (uint i=0; i < arg_count ; i++)
+  {
+    longlong res= args[i]->val_datetime_packed(thd);
+
+    /* Check if we need to stop (because of error or KILL) and stop the loop */
+    if (unlikely(args[i]->null_value))
+      return (null_value= 1);
+
+    if (i == 0 || (res < min_max ? cmp_sign : -cmp_sign) > 0)
+      min_max= res;
+  }
+  unpack_time(min_max, ltime, mysql_timestamp_type());
+
+  if (!(fuzzydate & TIME_TIME_ONLY) &&
+      unlikely((null_value= check_date_with_warn(thd, ltime, fuzzydate,
+                                         MYSQL_TIMESTAMP_ERROR))))
+    return true;
+
+  return (null_value= 0);
+}
+
+
+bool Item_func_min_max::get_time_native(THD *thd, MYSQL_TIME *ltime)
+{
+  DBUG_ASSERT(fixed());
+
+  Time value(thd, args[0], Time::Options(thd), decimals);
+  if (!value.is_valid_time())
+    return (null_value= true);
+
+  for (uint i= 1; i < arg_count ; i++)
+  {
+    Time tmp(thd, args[i], Time::Options(thd), decimals);
+    if (!tmp.is_valid_time())
+      return (null_value= true);
+
+    int cmp= value.cmp(&tmp);
+    if ((cmp_sign < 0 ? cmp : -cmp) < 0)
+      value= tmp;
+  }
+  value.copy_to_mysql_time(ltime);
+  return (null_value= 0);
+}
+
+
+String *Item_func_min_max::val_str_native(String *str)
+{
+  String *UNINIT_VAR(res);
+  for (uint i=0; i < arg_count ; i++)
+  {
+    if (i == 0)
+      res=args[i]->val_str(str);
+    else
+    {
+      String *res2;
+      res2= args[i]->val_str(res == str ? &tmp_value : str);
+      if (res2)
+      {
+        int cmp= sortcmp(res,res2,collation.collation);
+        if ((cmp_sign < 0 ? cmp : -cmp) < 0)
+          res=res2;
+      }
+    }
+    if ((null_value= args[i]->null_value))
+      return 0;
+  }
+  res->set_charset(collation.collation);
+  return res;
+}
+
+
+double Item_func_min_max::val_real_native()
+{
+  double value=0.0;
+  for (uint i=0; i < arg_count ; i++)
+  {
+    if (i == 0)
+      value= args[i]->val_real();
+    else
+    {
+      double tmp= args[i]->val_real();
+      if (!args[i]->null_value && (tmp < value ? cmp_sign : -cmp_sign) > 0)
+	value=tmp;
+    }
+    if ((null_value= args[i]->null_value))
+      break;
+  }
+  return value;
+}
+
+
+longlong Item_func_min_max::val_int_native()
+{
+  DBUG_ASSERT(fixed());
+  longlong value=0;
+  for (uint i=0; i < arg_count ; i++)
+  {
+    if (i == 0)
+      value=args[i]->val_int();
+    else
+    {
+      longlong tmp=args[i]->val_int();
+      if (!args[i]->null_value && (tmp < value ? cmp_sign : -cmp_sign) > 0)
+	value=tmp;
+    }
+    if ((null_value= args[i]->null_value))
+      break;
+  }
+  return value;
+}
+
+
+my_decimal *Item_func_min_max::val_decimal_native(my_decimal *dec)
+{
+  DBUG_ASSERT(fixed());
+  my_decimal tmp_buf, *tmp, *UNINIT_VAR(res);
+
+  for (uint i=0; i < arg_count ; i++)
+  {
+    if (i == 0)
+      res= args[i]->val_decimal(dec);
+    else
+    {
+      tmp= args[i]->val_decimal(&tmp_buf);      // Zero if NULL
+      if (tmp && (my_decimal_cmp(tmp, res) * cmp_sign) < 0)
+      {
+        if (tmp == &tmp_buf)
+        {
+          /* Move value out of tmp_buf as this will be reused on next loop */
+          my_decimal2decimal(tmp, dec);
+          res= dec;
+        }
+        else
+          res= tmp;
+      }
+    }
+    if ((null_value= args[i]->null_value))
+    {
+      res= 0;
+      break;
+    }
+  }
+  return res;
+}
+
+
+bool Item_func_min_max::val_native(THD *thd, Native *native)
+{
+  DBUG_ASSERT(fixed());
+  const Type_handler *handler= Item_hybrid_func::type_handler();
+  NativeBuffer<STRING_BUFFER_USUAL_SIZE> cur;
+  for (uint i= 0; i < arg_count; i++)
+  {
+    if (val_native_with_conversion_from_item(thd, args[i],
+                                             i == 0 ? native : &cur,
+                                             handler))
+      return true;
+    if (i > 0)
+    {
+      int cmp= handler->cmp_native(*native, cur);
+      if ((cmp_sign < 0 ? cmp : -cmp) < 0 && native->copy(cur))
+        return null_value= true;
+    }
+  }
+  return null_value= false;
+}
+
+
+longlong Item_func_bit_length::val_int()
+{
+  DBUG_ASSERT(fixed());
+  String *res= args[0]->val_str(&value);
+  return (null_value= !res) ? 0 : (longlong) res->length() * 8;
+}
+
+
+longlong Item_func_octet_length::val_int()
+{
+  DBUG_ASSERT(fixed());
+  String *res=args[0]->val_str(&value);
+  if (!res)
+  {
+    null_value=1;
+    return 0; /* purecov: inspected */
+  }
+  null_value=0;
+  return (longlong) res->length();
+}
+
+
+longlong Item_func_char_length::val_int()
+{
+  DBUG_ASSERT(fixed());
+  String *res=args[0]->val_str(&value);
+  if (!res)
+  {
+    null_value=1;
+    return 0; /* purecov: inspected */
+  }
+  null_value=0;
+  return (longlong) res->numchars();
+}
+
+
+longlong Item_func_coercibility::val_int()
+{
+  DBUG_ASSERT(fixed());
+  null_value= 0;
+  return (longlong) args[0]->collation.derivation;
+}
+
+
+longlong Item_func_locate::val_int()
+{
+  DBUG_ASSERT(fixed());
+  String *a=args[0]->val_str(&value1);
+  String *b=args[1]->val_str(&value2);
+  if (!a || !b)
+  {
+    null_value=1;
+    return 0; /* purecov: inspected */
+  }
+  null_value=0;
+  /* must be longlong to avoid truncation */
+  longlong start=  0; 
+  longlong start0= 0;
+  my_match_t match;
+
+  if (arg_count == 3)
+  {
+    start0= start= args[2]->val_int();
+
+    if ((start <= 0) || (start > a->length()))
+      return 0;
+    start0--; start--;
+
+    /* start is now sufficiently valid to pass to charpos function */
+    start= a->charpos((int) start);
+
+    if (start + b->length() > a->length())
+      return 0;
+  }
+
+  if (!b->length())				// Found empty string at start
+    return start + 1;
+  
+  if (!cmp_collation.collation->instr(a->ptr() + start,
+                                      (uint) (a->length() - start),
+                                      b->ptr(), b->length(),
+                                      &match, 1))
+    return 0;
+  return (longlong) match.mb_len + start0 + 1;
+}
+
+
+void Item_func_locate::print(String *str, enum_query_type query_type)
+{
+  str->append(STRING_WITH_LEN("locate("));
+  args[1]->print(str, query_type);
+  str->append(',');
+  args[0]->print(str, query_type);
+  if (arg_count == 3)
+  {
+    str->append(',');
+    args[2]->print(str, query_type);
+  }
+  str->append(')');
+}
+
+
+longlong Item_func_field::val_int()
+{
+  DBUG_ASSERT(fixed());
+
+  if (cmp_type == STRING_RESULT)
+  {
+    String *field;
+    if (!(field= args[0]->val_str(&value)))
+      return 0;
+    for (uint i=1 ; i < arg_count ; i++)
+    {
+      String *tmp_value=args[i]->val_str(&tmp);
+      if (tmp_value && !sortcmp(field,tmp_value,cmp_collation.collation))
+        return (longlong) (i);
+    }
+  }
+  else if (cmp_type == INT_RESULT)
+  {
+    longlong val= args[0]->val_int();
+    if (args[0]->null_value)
+      return 0;
+    for (uint i=1; i < arg_count ; i++)
+    {
+      if (val == args[i]->val_int() && !args[i]->null_value)
+        return (longlong) (i);
+    }
+  }
+  else if (cmp_type == DECIMAL_RESULT)
+  {
+    VDec dec(args[0]);
+    if (dec.is_null())
+      return 0;
+    my_decimal dec_arg_buf;
+    for (uint i=1; i < arg_count; i++)
+    {
+      my_decimal *dec_arg= args[i]->val_decimal(&dec_arg_buf);
+      if (!args[i]->null_value && !dec.cmp(dec_arg))
+        return (longlong) (i);
+    }
+  }
+  else
+  {
+    double val= args[0]->val_real();
+    if (args[0]->null_value)
+      return 0;
+    for (uint i=1; i < arg_count ; i++)
+    {
+      if (val == args[i]->val_real() && !args[i]->null_value)
+        return (longlong) (i);
+    }
+  }
+  return 0;
+}
+
+
+bool Item_func_field::fix_length_and_dec(THD *thd)
+{
+  base_flags&= ~item_base_t::MAYBE_NULL;
+  max_length=3;
+  cmp_type= args[0]->result_type();
+  for (uint i=1; i < arg_count ; i++)
+    cmp_type= item_cmp_type(cmp_type, args[i]->result_type());
+  if (cmp_type == STRING_RESULT)
+    return agg_arg_charsets_for_comparison(cmp_collation, args, arg_count);
+  return FALSE;
+}
+
+
+longlong Item_func_ascii::val_int()
+{
+  DBUG_ASSERT(fixed());
+  String *res=args[0]->val_str(&value);
+  if (!res)
+  {
+    null_value=1;
+    return 0;
+  }
+  null_value=0;
+  return (longlong) (res->length() ? (uchar) (*res)[0] : (uchar) 0);
+}
+
+longlong Item_func_ord::val_int()
+{
+  DBUG_ASSERT(fixed());
+  String *res=args[0]->val_str(&value);
+  if (!res)
+  {
+    null_value=1;
+    return 0;
+  }
+  null_value=0;
+  if (!res->length()) return 0;
+#ifdef USE_MB
+  if (res->use_mb())
+  {
+    const char *str=res->ptr();
+    uint32 n=0, l=my_ismbchar(res->charset(),str,str+res->length());
+    if (!l)
+      return (longlong)((uchar) *str);
+    while (l--)
+      n=(n<<8)|(uint32)((uchar) *str++);
+    return (longlong) n;
+  }
+#endif
+  return (longlong) ((uchar) (*res)[0]);
+}
+
+	/* Search after a string in a string of strings separated by ',' */
+	/* Returns number of found type >= 1 or 0 if not found */
+	/* This optimizes searching in enums to bit testing! */
+
+bool Item_func_find_in_set::fix_length_and_dec(THD *thd)
+{
+  decimals=0;
+  max_length=3;					// 1-999
+  if (args[0]->const_item() && args[1]->type() == FIELD_ITEM)
+  {
+    Field *field= ((Item_field*) args[1])->field;
+    if (field->real_type() == MYSQL_TYPE_SET)
+    {
+      String *find=args[0]->val_str(&value);
+      if (find)
+      {
+        // find is not NULL pointer so args[0] is not a null-value
+        DBUG_ASSERT(!args[0]->null_value);
+	enum_value= find_type(((Field_enum*) field)->typelib,find->ptr(),
+			      find->length(), 0);
+	enum_bit=0;
+	if (enum_value)
+	  enum_bit= 1ULL << (enum_value-1);
+      }
+    }
+  }
+  return agg_arg_charsets_for_comparison(cmp_collation, args, 2);
+}
+
+static const char separator=',';
+
+longlong Item_func_find_in_set::val_int()
+{
+  DBUG_ASSERT(fixed());
+  if (enum_value)
+  {
+    // enum_value is set iff args[0]->const_item() in fix_length_and_dec().
+    DBUG_ASSERT(args[0]->const_item());
+
+    ulonglong tmp= (ulonglong) args[1]->val_int();
+    null_value= args[1]->null_value;
+    /* 
+      No need to check args[0]->null_value since enum_value is set iff
+      args[0] is a non-null const item. Note: no DBUG_ASSERT on
+      args[0]->null_value here because args[0] may have been replaced
+      by an Item_cache on which val_int() has not been called. See
+      BUG#11766317
+    */
+    if (!null_value)
+    {
+      if (tmp & enum_bit)
+        return enum_value;
+    }
+    return 0L;
+  }
+
+  String *find=args[0]->val_str(&value);
+  String *buffer=args[1]->val_str(&value2);
+  if (!find || !buffer)
+  {
+    null_value=1;
+    return 0; /* purecov: inspected */
+  }
+  null_value=0;
+
+  if ((int) (buffer->length() - find->length()) >= 0)
+  {
+    my_wc_t wc= 0;
+    CHARSET_INFO *cs= cmp_collation.collation;
+    const char *str_begin= buffer->ptr();
+    const char *str_end= buffer->ptr();
+    const char *real_end= str_end+buffer->length();
+    const char *find_str= find->ptr();
+    uint find_str_len= find->length();
+    int position= 0;
+    while (1)
+    {
+      int symbol_len;
+      if ((symbol_len= cs->mb_wc(&wc, (uchar*) str_end,
+                                 (uchar*) real_end)) > 0)
+      {
+        const char *substr_end= str_end + symbol_len;
+        bool is_last_item= (substr_end == real_end);
+        bool is_separator= (wc == (my_wc_t) separator);
+        if (is_separator || is_last_item)
+        {
+          position++;
+          if (is_last_item && !is_separator)
+            str_end= substr_end;
+          if (!cs->strnncoll(str_begin, (uint) (str_end - str_begin),
+                             find_str, find_str_len))
+            return (longlong) position;
+          else
+            str_begin= substr_end;
+        }
+        str_end= substr_end;
+      }
+      else if (str_end - str_begin == 0 &&
+               find_str_len == 0 &&
+               wc == (my_wc_t) separator)
+        return (longlong) ++position;
+      else
+        return 0;
+    }
+  }
+  return 0;
+}
+
+
+class Func_handler_bit_count_int_to_slong:
+        public Item_handled_func::Handler_slong2
+{
+public:
+  Longlong_null to_longlong_null(Item_handled_func *item) const
+  {
+    DBUG_ASSERT(item->fixed());
+    return item->arguments()[0]->to_longlong_null().bit_count();
+  }
+};
+
+
+class Func_handler_bit_count_decimal_to_slong:
+        public Item_handled_func::Handler_slong2
+{
+public:
+  Longlong_null to_longlong_null(Item_handled_func *item) const
+  {
+    DBUG_ASSERT(item->fixed());
+    return VDec(item->arguments()[0]).to_xlonglong_null().bit_count();
+  }
+};
+
+
+bool Item_func_bit_count::fix_length_and_dec(THD *thd)
+{
+  static Func_handler_bit_count_int_to_slong ha_int_to_slong;
+  static Func_handler_bit_count_decimal_to_slong ha_dec_to_slong;
+  set_func_handler(args[0]->cmp_type() == INT_RESULT ?
+                   (const Handler *) &ha_int_to_slong :
+                   (const Handler *) &ha_dec_to_slong);
+  return m_func_handler->fix_length_and_dec(this);
+}
+
+
+/****************************************************************************
+** Functions to handle dynamic loadable functions
+** Original source by: Alexis Mikhailov <root@medinf.chuvashia.su>
+** Rewritten by monty.
+****************************************************************************/
+
+#ifdef HAVE_DLOPEN
+
+void udf_handler::cleanup()
+{
+  if (!not_original)
+  {
+    if (initialized)
+    {
+      if (u_d->func_deinit != NULL)
+      {
+        Udf_func_deinit deinit= u_d->func_deinit;
+        (*deinit)(&initid);
+      }
+      free_udf(u_d);
+      initialized= FALSE;
+    }
+    if (buffers)				// Because of bug in ecc
+      delete [] buffers;
+    buffers= 0;
+  }
+}
+
+
+bool
+udf_handler::fix_fields(THD *thd, Item_func_or_sum *func,
+			uint arg_count, Item **arguments)
+{
+  uchar buff[STACK_BUFF_ALLOC];			// Max argument in function
+  DBUG_ENTER("Item_udf_func::fix_fields");
+
+  if (check_stack_overrun(thd, STACK_MIN_SIZE, buff))
+    DBUG_RETURN(TRUE);				// Fatal error flag is set!
+
+  udf_func *tmp_udf=find_udf(u_d->name.str,u_d->name.length,1);
+
+  if (!tmp_udf)
+  {
+    my_error(ER_CANT_FIND_UDF, MYF(0), u_d->name.str);
+    DBUG_RETURN(TRUE);
+  }
+  u_d=tmp_udf;
+  args=arguments;
+
+  /* Fix all arguments */
+  func->base_flags&= ~item_base_t::MAYBE_NULL;
+  func->used_tables_and_const_cache_init();
+
+  if ((f_args.arg_count=arg_count))
+  {
+    if (!(f_args.arg_type= (Item_result*)
+	  thd->alloc(f_args.arg_count*sizeof(Item_result))))
+
+    {
+    err_exit:
+      free_udf(u_d);
+      DBUG_RETURN(TRUE);
+    }
+    uint i;
+    Item **arg,**arg_end;
+    for (i=0, arg=arguments, arg_end=arguments+arg_count;
+	 arg != arg_end ;
+	 arg++,i++)
+    {
+      if ((*arg)->fix_fields_if_needed_for_scalar(thd, arg))
+	DBUG_RETURN(true);
+      // we can't assign 'item' before, because fix_fields() can change arg
+      Item *item= *arg;
+      /*
+	TODO: We should think about this. It is not always
+	right way just to set an UDF result to return my_charset_bin
+	if one argument has binary sorting order.
+	The result collation should be calculated according to arguments
+	derivations in some cases and should not in other cases.
+	Moreover, some arguments can represent a numeric input
+	which doesn't effect the result character set and collation.
+	There is no a general rule for UDF. Everything depends on
+        the particular user defined function.
+      */
+      if (item->collation.collation->state & MY_CS_BINSORT)
+	func->collation.set(&my_charset_bin);
+      func->base_flags|= item->base_flags & item_base_t::MAYBE_NULL;
+      func->with_flags|= item->with_flags;
+      func->used_tables_and_const_cache_join(item);
+      f_args.arg_type[i]=item->result_type();
+    }
+    buffers=new (thd->mem_root) String[arg_count];
+    if (!buffers ||
+        !multi_alloc_root(thd->mem_root,
+                          &f_args.args,              arg_count * sizeof(char *),
+                          &f_args.lengths,           arg_count * sizeof(long),
+                          &f_args.maybe_null,        arg_count * sizeof(char),
+                          &num_buffer,               arg_count * sizeof(double),
+                          &f_args.attributes,        arg_count * sizeof(char *),
+                          &f_args.attribute_lengths, arg_count * sizeof(long),
+                          NullS))
+      goto err_exit;
+  }
+  if (func->fix_length_and_dec(thd))
+    DBUG_RETURN(TRUE);
+  initid.max_length=func->max_length;
+  initid.maybe_null=func->maybe_null();
+  initid.const_item=func->const_item_cache;
+  initid.decimals=func->decimals;
+  initid.ptr=0;
+  for (uint i1= 0 ; i1 < arg_count ; i1++)
+    buffers[i1].set_thread_specific();
+
+  if (u_d->func_init)
+  {
+    char init_msg_buff[MYSQL_ERRMSG_SIZE];
+    char *to=num_buffer;
+    for (uint i=0; i < arg_count; i++)
+    {
+      /*
+       For a constant argument i, args->args[i] points to the argument value. 
+       For non-constant, args->args[i] is NULL.
+      */
+      f_args.args[i]= NULL;         /* Non-const unless updated below. */
+
+      f_args.lengths[i]= arguments[i]->max_length;
+      f_args.maybe_null[i]= (char) arguments[i]->maybe_null();
+      f_args.attributes[i]= arguments[i]->name.str;
+      f_args.attribute_lengths[i]= (ulong)arguments[i]->name.length;
+
+      if (arguments[i]->const_item())
+      {
+        switch (arguments[i]->result_type()) {
+        case STRING_RESULT:
+        case DECIMAL_RESULT:
+        {
+          String *res= arguments[i]->val_str(&buffers[i]);
+          if (arguments[i]->null_value)
+            continue;
+          f_args.args[i]= (char*) res->c_ptr_safe();
+          f_args.lengths[i]= res->length();
+          break;
+        }
+        case INT_RESULT:
+          *((longlong*) to)= arguments[i]->val_int();
+          if (arguments[i]->null_value)
+            continue;
+          f_args.args[i]= to;
+          to+= ALIGN_SIZE(sizeof(longlong));
+          break;
+        case REAL_RESULT:
+          *((double*) to)= arguments[i]->val_real();
+          if (arguments[i]->null_value)
+            continue;
+          f_args.args[i]= to;
+          to+= ALIGN_SIZE(sizeof(double));
+          break;
+        case ROW_RESULT:
+        case TIME_RESULT:
+          DBUG_ASSERT(0);          // This case should never be chosen
+          break;
+        }
+      }
+    }
+    Udf_func_init init= u_d->func_init;
+    if (unlikely((error=(uchar) init(&initid, &f_args, init_msg_buff))))
+    {
+      my_error(ER_CANT_INITIALIZE_UDF, MYF(0),
+               u_d->name.str, init_msg_buff);
+      goto err_exit;
+    }
+    func->max_length=MY_MIN(initid.max_length,MAX_BLOB_WIDTH);
+    func->set_maybe_null(initid.maybe_null);
+    /*
+      The above call for init() can reset initid.const_item to "false",
+      e.g. when the UDF function wants to be non-deterministic.
+      See sequence_init() in udf_example.cc.
+    */
+    func->const_item_cache= initid.const_item;
+    func->decimals=MY_MIN(initid.decimals,NOT_FIXED_DEC);
+  }
+  initialized=1;
+  if (unlikely(error))
+  {
+    my_error(ER_CANT_INITIALIZE_UDF, MYF(0),
+             u_d->name.str, ER_THD(thd, ER_UNKNOWN_ERROR));
+    DBUG_RETURN(TRUE);
+  }
+  DBUG_RETURN(FALSE);
+}
+
+
+bool udf_handler::get_arguments()
+{
+  if (unlikely(error))
+    return 1;					// Got an error earlier
+  char *to= num_buffer;
+  uint str_count=0;
+  for (uint i=0; i < f_args.arg_count; i++)
+  {
+    f_args.args[i]=0;
+    switch (f_args.arg_type[i]) {
+    case STRING_RESULT:
+    case DECIMAL_RESULT:
+      {
+	String *res=args[i]->val_str(&buffers[str_count++]);
+	if (!(args[i]->null_value))
+	{
+	  f_args.args[i]=    (char*) res->ptr();
+	  f_args.lengths[i]= res->length();
+	}
+	else
+	{
+	  f_args.lengths[i]= 0;
+	}
+	break;
+      }
+    case INT_RESULT:
+      *((longlong*) to) = args[i]->val_int();
+      if (!args[i]->null_value)
+      {
+	f_args.args[i]=to;
+	to+= ALIGN_SIZE(sizeof(longlong));
+      }
+      break;
+    case REAL_RESULT:
+      *((double*) to)= args[i]->val_real();
+      if (!args[i]->null_value)
+      {
+	f_args.args[i]=to;
+	to+= ALIGN_SIZE(sizeof(double));
+      }
+      break;
+    case ROW_RESULT:
+    case TIME_RESULT:
+      DBUG_ASSERT(0);              // This case should never be chosen
+      break;
+    }
+  }
+  return 0;
+}
+
+/**
+  @return
+    (String*)NULL in case of NULL values
+*/
+String *udf_handler::val_str(String *str,String *save_str)
+{
+  uchar is_null_tmp=0;
+  ulong res_length;
+  DBUG_ENTER("udf_handler::val_str");
+
+  if (get_arguments())
+    DBUG_RETURN(0);
+  char * (*func)(UDF_INIT *, UDF_ARGS *, char *, ulong *, uchar *, uchar *)=
+    (char* (*)(UDF_INIT *, UDF_ARGS *, char *, ulong *, uchar *, uchar *))
+    u_d->func;
+
+  if ((res_length=str->alloced_length()) < MAX_FIELD_WIDTH)
+  {						// This happens VERY seldom
+    if (str->alloc(MAX_FIELD_WIDTH))
+    {
+      error=1;
+      DBUG_RETURN(0);
+    }
+  }
+  char *res=func(&initid, &f_args, (char*) str->ptr(), &res_length,
+		 &is_null_tmp, &error);
+  DBUG_PRINT("info", ("udf func returned, res_length: %lu", res_length));
+  if (is_null_tmp || !res || unlikely(error))	// The !res is for safety
+  {
+    DBUG_PRINT("info", ("Null or error"));
+    DBUG_RETURN(0);
+  }
+  if (res == str->ptr())
+  {
+    str->length(res_length);
+    DBUG_PRINT("exit", ("str: %*.s", (int) str->length(), str->ptr()));
+    DBUG_RETURN(str);
+  }
+  save_str->set(res, res_length, str->charset());
+  DBUG_PRINT("exit", ("save_str: %s", save_str->ptr()));
+  DBUG_RETURN(save_str);
+}
+
+
+/*
+  For the moment, UDF functions are returning DECIMAL values as strings
+*/
+
+my_decimal *udf_handler::val_decimal(my_bool *null_value, my_decimal *dec_buf)
+{
+  char buf[DECIMAL_MAX_STR_LENGTH+1], *end;
+  ulong res_length= DECIMAL_MAX_STR_LENGTH;
+
+  if (get_arguments())
+  {
+    *null_value=1;
+    return 0;
+  }
+  char *(*func)(UDF_INIT *, UDF_ARGS *, char *, ulong *, uchar *, uchar *)=
+    (char* (*)(UDF_INIT *, UDF_ARGS *, char *, ulong *, uchar *, uchar *))
+    u_d->func;
+
+  char *res= func(&initid, &f_args, buf, &res_length, &is_null, &error);
+  if (is_null || unlikely(error))
+  {
+    *null_value= 1;
+    return 0;
+  }
+  end= res+ res_length;
+  str2my_decimal(E_DEC_FATAL_ERROR, res, dec_buf, &end);
+  return dec_buf;
+}
+
+
+void Item_udf_func::cleanup()
+{
+  udf.cleanup();
+  Item_func::cleanup();
+}
+
+
+void Item_udf_func::print(String *str, enum_query_type query_type)
+{
+  str->append(func_name_cstring());
+  str->append('(');
+  for (uint i=0 ; i < arg_count ; i++)
+  {
+    if (i != 0)
+      str->append(',');
+    args[i]->print_item_w_name(str, query_type);
+  }
+  str->append(')');
+}
+
+
+double Item_func_udf_float::val_real()
+{
+  double res;
+  my_bool tmp_null_value;
+  DBUG_ASSERT(fixed());
+  DBUG_ENTER("Item_func_udf_float::val");
+  DBUG_PRINT("info",("result_type: %d  arg_count: %d",
+		     args[0]->result_type(), arg_count));
+  res= udf.val(&tmp_null_value);
+  null_value= tmp_null_value;
+  DBUG_RETURN(res);
+}
+
+
+String *Item_func_udf_float::val_str(String *str)
+{
+  DBUG_ASSERT(fixed());
+  double nr= val_real();
+  if (null_value)
+    return 0;					/* purecov: inspected */
+  str->set_real(nr,decimals,&my_charset_bin);
+  return str;
+}
+
+
+longlong Item_func_udf_int::val_int()
+{
+  longlong res;
+  my_bool tmp_null_value;
+  DBUG_ASSERT(fixed());
+  DBUG_ENTER("Item_func_udf_int::val_int");
+  res= udf.val_int(&tmp_null_value);
+  null_value= tmp_null_value;
+  DBUG_RETURN(res);
+}
+
+
+String *Item_func_udf_int::val_str(String *str)
+{
+  DBUG_ASSERT(fixed());
+  longlong nr=val_int();
+  if (null_value)
+    return 0;
+  str->set_int(nr, unsigned_flag, &my_charset_bin);
+  return str;
+}
+
+
+my_decimal *Item_func_udf_decimal::val_decimal(my_decimal *dec_buf)
+{
+  my_decimal *res;
+  my_bool tmp_null_value;
+  DBUG_ASSERT(fixed());
+  DBUG_ENTER("Item_func_udf_decimal::val_decimal");
+  DBUG_PRINT("info",("result_type: %d  arg_count: %d",
+                     args[0]->result_type(), arg_count));
+
+  res= udf.val_decimal(&tmp_null_value, dec_buf);
+  null_value= tmp_null_value;
+  DBUG_RETURN(res);
+}
+
+
+/* Default max_length is max argument length */
+
+bool Item_func_udf_str::fix_length_and_dec(THD *thd)
+{
+  DBUG_ENTER("Item_func_udf_str::fix_length_and_dec");
+  max_length=0;
+  for (uint i = 0; i < arg_count; i++)
+    set_if_bigger(max_length,args[i]->max_length);
+  DBUG_RETURN(FALSE);
+}
+
+String *Item_func_udf_str::val_str(String *str)
+{
+  DBUG_ASSERT(fixed());
+  String *res=udf.val_str(str,&str_value);
+  null_value = !res;
+  return res;
+}
+
+
+/**
+  @note
+  This has to come last in the udf_handler methods, or C for AIX
+  version 6.0.0.0 fails to compile with debugging enabled. (Yes, really.)
+*/
+
+udf_handler::~udf_handler()
+{
+  /* Everything should be properly cleaned up by this moment. */
+  DBUG_ASSERT(not_original || !(initialized || buffers));
+}
+
+#else
+bool udf_handler::get_arguments() { return 0; }
+#endif /* HAVE_DLOPEN */
+
+
+longlong Item_master_pos_wait::val_int()
+{
+  DBUG_ASSERT(fixed());
+  THD* thd = current_thd;
+  String *log_name = args[0]->val_str(&value);
+  int event_count= 0;
+  DBUG_ENTER("Item_master_pos_wait::val_int");
+
+  null_value=0;
+  if (thd->slave_thread || !log_name || !log_name->length())
+  {
+    null_value = 1;
+    DBUG_RETURN(0);
+  }
+#ifdef HAVE_REPLICATION
+  longlong pos = (ulong)args[1]->val_int();
+  longlong timeout = (arg_count>=3) ? args[2]->val_int() : 0 ;
+  String connection_name_buff;
+  LEX_CSTRING connection_name;
+  Master_info *mi= NULL;
+  if (arg_count >= 4)
+  {
+    String *con;
+    if (!(con= args[3]->val_str(&connection_name_buff)))
+      goto err;
+
+    connection_name.str= con->ptr();
+    connection_name.length= con->length();
+    if (check_master_connection_name(&connection_name))
+    {
+      my_error(ER_WRONG_ARGUMENTS, MYF(ME_WARNING),
+               "MASTER_CONNECTION_NAME");
+      goto err;
+    }
+  }
+  else
+    connection_name= thd->variables.default_master_connection;
+
+  if (!(mi= get_master_info(&connection_name, Sql_condition::WARN_LEVEL_WARN)))
+    goto err;
+
+  if ((event_count = mi->rli.wait_for_pos(thd, log_name, pos, timeout)) == -2)
+  {
+    null_value = 1;
+    event_count=0;
+  }
+  mi->release();
+#endif
+  DBUG_PRINT("exit", ("event_count: %d  null_value: %d", event_count,
+                      (int) null_value));
+  DBUG_RETURN(event_count);
+
+#ifdef HAVE_REPLICATION
+err:
+  {
+    null_value = 1;
+    DBUG_RETURN(0);
+  }
+#endif
+}
+
+
+longlong Item_master_gtid_wait::val_int()
+{
+  DBUG_ASSERT(fixed());
+  longlong result= 0;
+  String *gtid_pos __attribute__((unused)) = args[0]->val_str(&value);
+  DBUG_ENTER("Item_master_gtid_wait::val_int");
+
+  if (args[0]->null_value)
+  {
+    null_value= 1;
+    DBUG_RETURN(0);
+  }
+
+  null_value=0;
+#ifdef HAVE_REPLICATION
+  THD* thd= current_thd;
+  longlong timeout_us;
+
+  if (arg_count==2 && !args[1]->null_value)
+    timeout_us= (longlong)(1e6*args[1]->val_real());
+  else
+    timeout_us= (longlong)-1;
+
+  result= rpl_global_gtid_waiting.wait_for_pos(thd, gtid_pos, timeout_us);
+#else
+  null_value= 0;
+#endif /* REPLICATION */
+  DBUG_RETURN(result);
+}
+
+
+/**
+  Enables a session to wait on a condition until a timeout or a network
+  disconnect occurs.
+
+  @remark The connection is polled every m_interrupt_interval nanoseconds.
+*/
+
+class Interruptible_wait
+{
+  THD *m_thd;
+  struct timespec m_abs_timeout;
+  static const ulonglong m_interrupt_interval;
+
+  public:
+    Interruptible_wait(THD *thd)
+    : m_thd(thd) {}
+
+    ~Interruptible_wait() = default;
+
+  public:
+    /**
+      Set the absolute timeout.
+
+      @param timeout The amount of time in nanoseconds to wait
+    */
+    void set_timeout(ulonglong timeout)
+    {
+      /*
+        Calculate the absolute system time at the start so it can
+        be controlled in slices. It relies on the fact that once
+        the absolute time passes, the timed wait call will fail
+        automatically with a timeout error.
+      */
+      set_timespec_nsec(m_abs_timeout, timeout);
+    }
+
+    /** The timed wait. */
+    int wait(mysql_cond_t *, mysql_mutex_t *);
+};
+
+
+/** Time to wait before polling the connection status. */
+const ulonglong Interruptible_wait::m_interrupt_interval= 5 * 1000000000ULL;
+
+
+/**
+  Wait for a given condition to be signaled.
+
+  @param cond   The condition variable to wait on.
+  @param mutex  The associated mutex.
+
+  @remark The absolute timeout is preserved across calls.
+
+  @retval return value from mysql_cond_timedwait
+*/
+
+int Interruptible_wait::wait(mysql_cond_t *cond, mysql_mutex_t *mutex)
+{
+  int error;
+  struct timespec timeout;
+
+  while (1)
+  {
+    /* Wait for a fixed interval. */
+    set_timespec_nsec(timeout, m_interrupt_interval);
+
+    /* But only if not past the absolute timeout. */
+    if (cmp_timespec(timeout, m_abs_timeout) > 0)
+      timeout= m_abs_timeout;
+
+    error= mysql_cond_timedwait(cond, mutex, &timeout);
+    if (m_thd->check_killed())
+      break;
+    if (error == ETIMEDOUT || error == ETIME)
+    {
+      /* Return error if timed out or connection is broken. */
+      if (!cmp_timespec(timeout, m_abs_timeout) || !m_thd->is_connected())
+        break;
+    }
+    /* Otherwise, propagate status to the caller. */
+    else
+      break;
+  }
+
+  return error;
+}
+
+
+/**
+  For locks with EXPLICIT duration, MDL returns a new ticket
+  every time a lock is granted. This allows to implement recursive
+  locks without extra allocation or additional data structures, such
+  as below. However, if there are too many tickets in the same
+  MDL_context, MDL_context::find_ticket() is getting too slow,
+  since it's using a linear search.
+  This is why a separate structure is allocated for a user
+  level lock, and before requesting a new lock from MDL,
+  GET_LOCK() checks thd->ull_hash if such lock is already granted,
+  and if so, simply increments a reference counter.
+*/
+
+class User_level_lock
+{
+public:
+  MDL_ticket *lock;
+  int refs;
+};
+
+
+/** Extract a hash key from User_level_lock. */
+
+uchar *ull_get_key(const uchar *ptr, size_t *length,
+                   my_bool not_used __attribute__((unused)))
+{
+  User_level_lock *ull = (User_level_lock*) ptr;
+  MDL_key *key = ull->lock->get_key();
+  *length= key->length();
+  return (uchar*) key->ptr();
+}
+
+
+/**
+  Release all user level locks for this THD.
+*/
+
+void mysql_ull_cleanup(THD *thd)
+{
+  User_level_lock *ull;
+  DBUG_ENTER("mysql_ull_cleanup");
+
+  for (uint i= 0; i < thd->ull_hash.records; i++)
+  {
+    ull = (User_level_lock*) my_hash_element(&thd->ull_hash, i);
+    thd->mdl_context.release_lock(ull->lock);
+    my_free(ull);
+  }
+
+  my_hash_free(&thd->ull_hash);
+
+  DBUG_VOID_RETURN;
+}
+
+
+/**
+  Set explicit duration for metadata locks corresponding to
+  user level locks to protect them from being released at the end
+  of transaction.
+*/
+
+void mysql_ull_set_explicit_lock_duration(THD *thd)
+{
+  User_level_lock *ull;
+  DBUG_ENTER("mysql_ull_set_explicit_lock_duration");
+
+  for (uint i= 0; i < thd->ull_hash.records; i++)
+  {
+    ull= (User_level_lock*) my_hash_element(&thd->ull_hash, i);
+    thd->mdl_context.set_lock_duration(ull->lock, MDL_EXPLICIT);
+  }
+  DBUG_VOID_RETURN;
+}
+
+
+/**
+  When MDL detects a lock wait timeout, it pushes
+  an error into the statement diagnostics area.
+  For GET_LOCK(), lock wait timeout is not an error,
+  but a special return value (0).
+  Similarly, killing get_lock wait is not an error either,
+  but a return value NULL.
+  Capture and suppress lock wait timeouts and kills.
+*/
+
+class Lock_wait_timeout_handler: public Internal_error_handler
+{
+public:
+  Lock_wait_timeout_handler() :m_lock_wait_timeout(false) {}
+
+  bool m_lock_wait_timeout;
+
+  bool handle_condition(THD * /* thd */, uint sql_errno,
+                        const char * /* sqlstate */,
+                        Sql_condition::enum_warning_level* /* level */,
+                        const char *message,
+                        Sql_condition ** /* cond_hdl */);
+};
+
+bool
+Lock_wait_timeout_handler::
+handle_condition(THD *thd, uint sql_errno,
+                 const char * /* sqlstate */,
+                 Sql_condition::enum_warning_level* /* level */,
+                 const char *message,
+                 Sql_condition ** /* cond_hdl */)
+{
+  if (sql_errno == ER_LOCK_WAIT_TIMEOUT)
+  {
+    m_lock_wait_timeout= true;
+    return true;                                /* condition handled */
+  }
+  if (thd->is_killed())
+    return true;
+
+  return false;
+}
+
+
+static int ull_name_ok(String *name)
+{
+  if (!name || !name->length())
+    return 0;
+
+  if (name->length() > NAME_LEN)
+  {
+    my_error(ER_TOO_LONG_IDENT, MYF(0), name->c_ptr_safe());
+    return 0;
+  }
+  return 1;
+}
+
+
+/**
+  Get a user level lock.
+
+  @retval
+    1    : Got lock
+  @retval
+    0    : Timeout
+  @retval
+    NULL : Error
+*/
+
+longlong Item_func_get_lock::val_int()
+{
+  DBUG_ASSERT(fixed());
+  String *res= args[0]->val_str(&value);
+  double timeout= args[1]->val_real();
+  THD *thd= current_thd;
+  User_level_lock *ull;
+  DBUG_ENTER("Item_func_get_lock::val_int");
+
+  null_value= 1;
+  /*
+    In slave thread no need to get locks, everything is serialized. Anyway
+    there is no way to make GET_LOCK() work on slave like it did on master
+    (i.e. make it return exactly the same value) because we don't have the
+    same other concurrent threads environment. No matter what we return here,
+    it's not guaranteed to be same as on master.
+  */
+  if (thd->slave_thread)
+  {
+    null_value= 0;
+    DBUG_RETURN(1);
+  }
+
+  if (args[1]->null_value ||
+      (!args[1]->unsigned_flag && ((longlong) timeout < 0)))
+  {
+    char buf[22];
+    if (args[1]->null_value)
+      strmov(buf, "NULL");
+    else
+      llstr(((longlong) timeout), buf);
+    push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
+                        ER_WRONG_VALUE_FOR_TYPE, ER(ER_WRONG_VALUE_FOR_TYPE),
+                        "timeout", buf, "get_lock");
+    null_value= 1;
+    DBUG_RETURN(0);
+  }
+
+  if (!ull_name_ok(res))
+    DBUG_RETURN(0);
+  DBUG_PRINT("enter", ("lock: %.*s", res->length(), res->ptr()));
+  /* HASH entries are of type User_level_lock. */
+  if (! my_hash_inited(&thd->ull_hash) &&
+        my_hash_init(key_memory_User_level_lock, &thd->ull_hash,
+                     &my_charset_bin, 16 /* small hash */, 0, 0, ull_get_key,
+                     NULL, 0))
+  {
+    DBUG_RETURN(0);
+  }
+
+  MDL_request ull_request;
+  MDL_REQUEST_INIT(&ull_request, MDL_key::USER_LOCK, res->c_ptr_safe(), "",
+                   MDL_SHARED_NO_WRITE, MDL_EXPLICIT);
+  MDL_key *ull_key= &ull_request.key;
+
+
+  if ((ull= (User_level_lock*)
+       my_hash_search(&thd->ull_hash, ull_key->ptr(), ull_key->length())))
+  {
+    /* Recursive lock */
+    ull->refs++;
+    null_value= 0;
+    DBUG_PRINT("info", ("recursive lock, ref-count: %d", (int) ull->refs));
+    DBUG_RETURN(1);
+  }
+
+  Lock_wait_timeout_handler lock_wait_timeout_handler;
+  thd->push_internal_handler(&lock_wait_timeout_handler);
+  bool error= thd->mdl_context.acquire_lock(&ull_request, timeout);
+  (void) thd->pop_internal_handler();
+  if (unlikely(error))
+  {
+    if (lock_wait_timeout_handler.m_lock_wait_timeout)
+      null_value= 0;
+    DBUG_RETURN(0);
+  }
+
+  ull= (User_level_lock*) my_malloc(key_memory_User_level_lock,
+                                    sizeof(User_level_lock),
+                                    MYF(MY_WME|MY_THREAD_SPECIFIC));
+  if (ull == NULL)
+  {
+    thd->mdl_context.release_lock(ull_request.ticket);
+    DBUG_RETURN(0);
+  }
+
+  ull->lock= ull_request.ticket;
+  ull->refs= 1;
+
+  if (my_hash_insert(&thd->ull_hash, (uchar*) ull))
+  {
+    thd->mdl_context.release_lock(ull->lock);
+    my_free(ull);
+    DBUG_RETURN(0);
+  }
+  null_value= 0;
+
+  DBUG_RETURN(1);
+}
+
+
+/**
+  Release all user level locks.
+  @return
+    - N if N-lock released
+    - 0 if lock wasn't held
+*/
+longlong Item_func_release_all_locks::val_int()
+{
+  DBUG_ASSERT(fixed());
+  THD *thd= current_thd;
+  ulong num_unlocked= 0;
+  DBUG_ENTER("Item_func_release_all_locks::val_int");
+  for (size_t i= 0; i < thd->ull_hash.records; i++)
+  {
+    auto ull= (User_level_lock *) my_hash_element(&thd->ull_hash, i);
+    thd->mdl_context.release_lock(ull->lock);
+    num_unlocked+= ull->refs;
+    my_free(ull);
+  }
+  my_hash_free(&thd->ull_hash);
+  DBUG_RETURN(num_unlocked);
+}
+
+
+/**
+  Release a user level lock.
+  @return
+    - 1 if lock released
+    - 0 if lock wasn't held
+    - (SQL) NULL if no such lock
+*/
+
+longlong Item_func_release_lock::val_int()
+{
+  DBUG_ASSERT(fixed());
+  String *res= args[0]->val_str(&value);
+  THD *thd= current_thd;
+  DBUG_ENTER("Item_func_release_lock::val_int");
+  null_value= 1;
+
+  if (!ull_name_ok(res))
+    DBUG_RETURN(0);
+
+  DBUG_PRINT("enter", ("lock: %.*s", res->length(), res->ptr()));
+
+  MDL_key ull_key;
+  ull_key.mdl_key_init(MDL_key::USER_LOCK, res->c_ptr_safe(), "");
+
+  User_level_lock *ull;
+
+  if (!my_hash_inited(&thd->ull_hash) ||
+      !(ull=
+        (User_level_lock*) my_hash_search(&thd->ull_hash,
+                                          ull_key.ptr(), ull_key.length())))
+  {
+    null_value= thd->mdl_context.get_lock_owner(&ull_key) == 0;
+    DBUG_RETURN(0);
+  }
+  DBUG_PRINT("info", ("ref count: %d", (int) ull->refs));
+  null_value= 0;
+  if (--ull->refs == 0)
+  {
+    my_hash_delete(&thd->ull_hash, (uchar*) ull);
+    thd->mdl_context.release_lock(ull->lock);
+    my_free(ull);
+  }
+  DBUG_RETURN(1);
+}
+
+
+/**
+  Check a user level lock.
+
+  Sets null_value=TRUE on error.
+
+  @retval
+    1		Available
+  @retval
+    0		Already taken, or error
+*/
+
+longlong Item_func_is_free_lock::val_int()
+{
+  DBUG_ASSERT(fixed());
+  String *res= args[0]->val_str(&value);
+  THD *thd= current_thd;
+  null_value= 1;
+
+  if (!ull_name_ok(res))
+    return 0;
+
+  MDL_key ull_key;
+  ull_key.mdl_key_init(MDL_key::USER_LOCK, res->c_ptr_safe(), "");
+
+  null_value= 0;
+  return thd->mdl_context.get_lock_owner(&ull_key) == 0;
+}
+
+
+longlong Item_func_is_used_lock::val_int()
+{
+  DBUG_ASSERT(fixed());
+  String *res= args[0]->val_str(&value);
+  THD *thd= current_thd;
+  null_value= 1;
+
+  if (!ull_name_ok(res))
+    return 0;
+
+  MDL_key ull_key;
+  ull_key.mdl_key_init(MDL_key::USER_LOCK, res->c_ptr_safe(), "");
+  ulong thread_id = thd->mdl_context.get_lock_owner(&ull_key);
+  if (thread_id == 0)
+    return 0;
+
+  null_value= 0;
+  return thread_id;
+}
+
+
+longlong Item_func_last_insert_id::val_int()
+{
+  THD *thd= current_thd;
+  DBUG_ASSERT(fixed());
+  if (arg_count)
+  {
+    longlong value= args[0]->val_int();
+    null_value= args[0]->null_value;
+    /*
+      LAST_INSERT_ID(X) must affect the client's mysql_insert_id() as
+      documented in the manual. We don't want to touch
+      first_successful_insert_id_in_cur_stmt because it would make
+      LAST_INSERT_ID(X) take precedence over an generated auto_increment
+      value for this row.
+    */
+    thd->arg_of_last_insert_id_function= TRUE;
+    thd->first_successful_insert_id_in_prev_stmt= value;
+    return value;
+  }
+  return
+    static_cast<longlong>(thd->read_first_successful_insert_id_in_prev_stmt());
+}
+
+
+bool Item_func_last_insert_id::fix_fields(THD *thd, Item **ref)
+{
+  thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);
+  return Item_int_func::fix_fields(thd, ref);
+}
+
+
+/* This function is just used to test speed of different functions */
+
+longlong Item_func_benchmark::val_int()
+{
+  DBUG_ASSERT(fixed());
+  char buff[MAX_FIELD_WIDTH];
+  String tmp(buff,sizeof(buff), &my_charset_bin);
+  my_decimal tmp_decimal;
+  THD *thd= current_thd;
+  ulonglong loop_count;
+
+  loop_count= (ulonglong) args[0]->val_int();
+
+  if (args[0]->null_value ||
+      (!args[0]->unsigned_flag && (((longlong) loop_count) < 0)))
+  {
+    if (!args[0]->null_value)
+    {
+      char buff[22];
+      llstr(((longlong) loop_count), buff);
+      push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
+                          ER_WRONG_VALUE_FOR_TYPE,
+                          ER_THD(thd, ER_WRONG_VALUE_FOR_TYPE),
+                          "count", buff, "benchmark");
+    }
+
+    null_value= 1;
+    return 0;
+  }
+
+  null_value=0;
+  for (ulonglong loop=0 ; loop < loop_count && !thd->killed; loop++)
+  {
+    switch (args[1]->result_type()) {
+    case REAL_RESULT:
+      (void) args[1]->val_real();
+      break;
+    case INT_RESULT:
+      (void) args[1]->val_int();
+      break;
+    case STRING_RESULT:
+      (void) args[1]->val_str(&tmp);
+      break;
+    case DECIMAL_RESULT:
+      (void) args[1]->val_decimal(&tmp_decimal);
+      break;
+    case ROW_RESULT:
+    case TIME_RESULT:
+      DBUG_ASSERT(0);              // This case should never be chosen
+      return 0;
+    }
+  }
+  return 0;
+}
+
+
+void Item_func_benchmark::print(String *str, enum_query_type query_type)
+{
+  str->append(STRING_WITH_LEN("benchmark("));
+  args[0]->print(str, query_type);
+  str->append(',');
+  args[1]->print(str, query_type);
+  str->append(')');
+}
+
+
+mysql_mutex_t LOCK_item_func_sleep;
+
+#ifdef HAVE_PSI_INTERFACE
+static PSI_mutex_key key_LOCK_item_func_sleep;
+
+static PSI_mutex_info item_func_sleep_mutexes[]=
+{
+  { &key_LOCK_item_func_sleep, "LOCK_item_func_sleep", PSI_FLAG_GLOBAL}
+};
+
+
+static void init_item_func_sleep_psi_keys(void)
+{
+  const char* category= "sql";
+  int count;
+
+  if (PSI_server == NULL)
+    return;
+
+  count= array_elements(item_func_sleep_mutexes);
+  PSI_server->register_mutex(category, item_func_sleep_mutexes, count);
+}
+#endif
+
+static bool item_func_sleep_inited= 0;
+
+
+void item_func_sleep_init(void)
+{
+#ifdef HAVE_PSI_INTERFACE
+  init_item_func_sleep_psi_keys();
+#endif
+
+  mysql_mutex_init(key_LOCK_item_func_sleep, &LOCK_item_func_sleep, MY_MUTEX_INIT_SLOW);
+  item_func_sleep_inited= 1;
+}
+
+
+void item_func_sleep_free(void)
+{
+  if (item_func_sleep_inited)
+  {
+    item_func_sleep_inited= 0;
+    mysql_mutex_destroy(&LOCK_item_func_sleep);
+  }
+}
+
+
+/** This function is just used to create tests with time gaps. */
+
+longlong Item_func_sleep::val_int()
+{
+  THD *thd= current_thd;
+  Interruptible_wait timed_cond(thd);
+  mysql_cond_t cond;
+  double timeout;
+  int error;
+
+  DBUG_ASSERT(fixed());
+
+  timeout= args[0]->val_real();
+  /*
+    On 64-bit OSX mysql_cond_timedwait() waits forever
+    if passed abstime time has already been exceeded by 
+    the system time.
+    When given a very short timeout (< 10 mcs) just return 
+    immediately.
+    We assume that the lines between this test and the call 
+    to mysql_cond_timedwait() will be executed in less than 0.00001 sec.
+  */
+  if (timeout < 0.00001)
+    return 0;
+
+  timed_cond.set_timeout((ulonglong) (timeout * 1000000000.0));
+
+  mysql_cond_init(key_item_func_sleep_cond, &cond, NULL);
+  mysql_mutex_lock(&LOCK_item_func_sleep);
+
+  THD_STAGE_INFO(thd, stage_user_sleep);
+  thd->mysys_var->current_mutex= &LOCK_item_func_sleep;
+  thd->mysys_var->current_cond=  &cond;
+
+  error= 0;
+  thd_wait_begin(thd, THD_WAIT_SLEEP);
+  while (!thd->killed)
+  {
+    error= timed_cond.wait(&cond, &LOCK_item_func_sleep);
+    if (error == ETIMEDOUT || error == ETIME)
+      break;
+    error= 0;
+  }
+  thd_wait_end(thd);
+  mysql_mutex_unlock(&LOCK_item_func_sleep);
+  mysql_mutex_lock(&thd->mysys_var->mutex);
+  thd->mysys_var->current_mutex= 0;
+  thd->mysys_var->current_cond=  0;
+  mysql_mutex_unlock(&thd->mysys_var->mutex);
+
+  mysql_cond_destroy(&cond);
+
+#ifdef ENABLED_DEBUG_SYNC
+  DBUG_EXECUTE_IF("sleep_inject_query_done_debug_sync", {
+      debug_sync_set_action
+        (thd, STRING_WITH_LEN("dispatch_command_end SIGNAL query_done"));
+    };);
+#endif
+
+  return MY_TEST(!error);                  // Return 1 killed
+}
+
+
+bool Item_func_user_var::check_vcol_func_processor(void *arg)
+{
+  return mark_unsupported_function("@", name.str, arg, VCOL_NON_DETERMINISTIC);
+}
+
+#define extra_size sizeof(double)
+
+user_var_entry *get_variable(HASH *hash, LEX_CSTRING *name,
+                             bool create_if_not_exists)
+{
+  user_var_entry *entry;
+
+  if (!(entry = (user_var_entry*) my_hash_search(hash, (uchar*) name->str,
+                                                 name->length)) &&
+      create_if_not_exists)
+  {
+    size_t size=ALIGN_SIZE(sizeof(user_var_entry))+name->length+1+extra_size;
+    if (!my_hash_inited(hash))
+      return 0;
+    if (!(entry = (user_var_entry*) my_malloc(key_memory_user_var_entry, size,
+                                              MYF(MY_WME | ME_FATAL |
+                                                  MY_THREAD_SPECIFIC))))
+      return 0;
+    entry->name.str=(char*) entry+ ALIGN_SIZE(sizeof(user_var_entry))+
+      extra_size;
+    entry->name.length=name->length;
+    entry->value=0;
+    entry->length=0;
+    entry->update_query_id=0;
+    entry->set_charset(NULL);
+    entry->unsigned_flag= 0;
+    /*
+      If we are here, we were called from a SET or a query which sets a
+      variable. Imagine it is this:
+      INSERT INTO t SELECT @a:=10, @a:=@a+1.
+      Then when we have a Item_func_get_user_var (because of the @a+1) so we
+      think we have to write the value of @a to the binlog. But before that,
+      we have a Item_func_set_user_var to create @a (@a:=10), in this we mark
+      the variable as "already logged" (line below) so that it won't be logged
+      by Item_func_get_user_var (because that's not necessary).
+    */
+    entry->used_query_id=current_thd->query_id;
+    entry->type=STRING_RESULT;
+    memcpy((char*) entry->name.str, name->str, name->length+1);
+    if (my_hash_insert(hash,(uchar*) entry))
+    {
+      my_free(entry);
+      return 0;
+    }
+  }
+  return entry;
+}
+
+
+void Item_func_set_user_var::cleanup()
+{
+  Item_func::cleanup();
+  m_var_entry= NULL;
+}
+
+
+bool Item_func_set_user_var::set_entry(THD *thd, bool create_if_not_exists)
+{
+  if (m_var_entry && thd->thread_id == entry_thread_id)
+    goto end; // update entry->update_query_id for PS
+  if (!(m_var_entry= get_variable(&thd->user_vars, &name, create_if_not_exists)))
+  {
+    entry_thread_id= 0;
+    return TRUE;
+  }
+  entry_thread_id= thd->thread_id;
+  /* 
+     Remember the last query which updated it, this way a query can later know
+     if this variable is a constant item in the query (it is if update_query_id
+     is different from query_id).
+  */
+end:
+  m_var_entry->update_query_id= thd->query_id;
+  return FALSE;
+}
+
+
+/*
+  When a user variable is updated (in a SET command or a query like
+  SELECT @a:= ).
+*/
+
+bool Item_func_set_user_var::fix_fields(THD *thd, Item **ref)
+{
+  DBUG_ASSERT(fixed() == 0);
+  /* fix_fields will call Item_func_set_user_var::fix_length_and_dec */
+  if (Item_func::fix_fields(thd, ref) || set_entry(thd, TRUE))
+    return TRUE;
+  /*
+    As it is wrong and confusing to associate any 
+    character set with NULL, @a should be latin2
+    after this query sequence:
+
+      SET @a=_latin2'string';
+      SET @a=NULL;
+
+    I.e. the second query should not change the charset
+    to the current default value, but should keep the 
+    original value assigned during the first query.
+    In order to do it, we don't copy charset
+    from the argument if the argument is NULL
+    and the variable has previously been initialized.
+  */
+  null_item= (args[0]->type() == NULL_ITEM);
+  if (!m_var_entry->charset() || !null_item)
+    m_var_entry->set_charset(args[0]->collation.derivation == DERIVATION_NUMERIC ?
+                             &my_charset_numeric : args[0]->collation.collation);
+  collation.set(m_var_entry->charset(),
+                args[0]->collation.derivation == DERIVATION_NUMERIC ?
+                DERIVATION_NUMERIC : DERIVATION_IMPLICIT);
+  switch (args[0]->result_type()) {
+  case STRING_RESULT:
+  case TIME_RESULT:
+    set_handler(type_handler_long_blob.
+                type_handler_adjusted_to_max_octet_length(max_length,
+                                                          collation.collation));
+    break;
+  case REAL_RESULT:
+    set_handler(&type_handler_double);
+    break;
+  case INT_RESULT:
+    set_handler(Type_handler::type_handler_long_or_longlong(max_char_length(),
+                                                            unsigned_flag));
+    break;
+  case DECIMAL_RESULT:
+    set_handler(&type_handler_newdecimal);
+    break;
+  case ROW_RESULT:
+    DBUG_ASSERT(0);
+    set_handler(&type_handler_row);
+    break;
+  }
+  if (thd->lex->current_select)
+  {
+    /*
+      When this function is used in a derived table/view force the derived
+      table to be materialized to preserve possible side-effect of setting a
+      user variable.
+    */
+    SELECT_LEX_UNIT *unit= thd->lex->current_select->master_unit();
+    TABLE_LIST *derived;
+    for (derived= unit->derived;
+         derived;
+         derived= unit->derived)
+    {
+      derived->set_materialized_derived();
+      derived->prohibit_cond_pushdown= true;
+      if (unit->with_element && unit->with_element->is_recursive)
+        break;
+      unit= derived->select_lex->master_unit();
+    }
+  }
+
+  return FALSE;
+}
+
+
+bool
+Item_func_set_user_var::fix_length_and_dec(THD *thd)
+{
+  base_flags|= (args[0]->base_flags & item_base_t::MAYBE_NULL);
+  decimals=args[0]->decimals;
+  if (args[0]->collation.derivation == DERIVATION_NUMERIC)
+  {
+    collation.set(DERIVATION_NUMERIC);
+    fix_length_and_charset(args[0]->max_char_length(), &my_charset_numeric);
+  }
+  else
+  {
+    collation.set(DERIVATION_IMPLICIT);
+    fix_length_and_charset(args[0]->max_char_length(),
+                           args[0]->collation.collation);
+  }
+  unsigned_flag= args[0]->unsigned_flag;
+  return FALSE;
+}
+
+
+/*
+  Mark field in read_map
+
+  NOTES
+    This is used by filesort to register used fields in a a temporary
+    column read set or to register used fields in a view
+*/
+
+bool Item_func_set_user_var::register_field_in_read_map(void *arg)
+{
+  if (result_field)
+  {
+    TABLE *table= (TABLE *) arg;
+    if (result_field->table == table || !table)
+      bitmap_set_bit(result_field->table->read_set, result_field->field_index);
+    if (result_field->vcol_info)
+      return result_field->vcol_info->
+               expr->walk(&Item::register_field_in_read_map, 1, arg);
+  }
+  return 0;
+}
+
+/*
+  Mark field in bitmap supplied as *arg
+
+*/
+
+bool Item_func_set_user_var::register_field_in_bitmap(void *arg)
+{
+  MY_BITMAP *bitmap = (MY_BITMAP *) arg;
+  DBUG_ASSERT(bitmap);
+  if (result_field)
+  {
+    if (!bitmap)
+      return 1;
+    bitmap_set_bit(bitmap, result_field->field_index);
+  }
+  return 0;
+}
+
+/**
+  Set value to user variable.
+
+  @param entry          pointer to structure representing variable
+  @param set_null       should we set NULL value ?
+  @param ptr            pointer to buffer with new value
+  @param length         length of new value
+  @param type           type of new value
+  @param cs             charset info for new value
+  @param dv             derivation for new value
+  @param unsigned_arg   indicates if a value of type INT_RESULT is unsigned
+
+  @note Sets error and fatal error if allocation fails.
+
+  @retval
+    false   success
+  @retval
+    true    failure
+*/
+
+bool
+update_hash(user_var_entry *entry, bool set_null, void *ptr, size_t length,
+            Item_result type, CHARSET_INFO *cs,
+            bool unsigned_arg)
+{
+  if (set_null)
+  {
+    char *pos= (char*) entry+ ALIGN_SIZE(sizeof(user_var_entry));
+    if (entry->value && entry->value != pos)
+      my_free(entry->value);
+    entry->value= 0;
+    entry->length= 0;
+  }
+  else
+  {
+    if (type == STRING_RESULT)
+      length++;					// Store strings with end \0
+    if (length <= extra_size)
+    {
+      /* Save value in value struct */
+      char *pos= (char*) entry+ ALIGN_SIZE(sizeof(user_var_entry));
+      if (entry->value != pos)
+      {
+	if (entry->value)
+	  my_free(entry->value);
+	entry->value=pos;
+      }
+    }
+    else
+    {
+      /* Allocate variable */
+      if (entry->length != length)
+      {
+	char *pos= (char*) entry+ ALIGN_SIZE(sizeof(user_var_entry));
+	if (entry->value == pos)
+	  entry->value=0;
+        entry->value= (char*) my_realloc(key_memory_user_var_entry_value,
+                                         entry->value, length,
+                                         MYF(MY_ALLOW_ZERO_PTR | MY_WME |
+                                             ME_FATAL | MY_THREAD_SPECIFIC));
+        if (!entry->value)
+	  return 1;
+      }
+    }
+    if (type == STRING_RESULT)
+    {
+      length--;					// Fix length change above
+      entry->value[length]= 0;			// Store end \0
+    }
+    if (length)
+      memmove(entry->value, ptr, length);
+    if (type == DECIMAL_RESULT)
+      ((my_decimal*)entry->value)->fix_buffer_pointer();
+    entry->length= length;
+    entry->set_charset(cs);
+    entry->unsigned_flag= unsigned_arg;
+  }
+  entry->type=type;
+#ifdef USER_VAR_TRACKING
+#ifndef EMBEDDED_LIBRARY
+  THD *thd= current_thd;
+  thd->session_tracker.user_variables.mark_as_changed(thd, entry);
+#endif
+#endif // USER_VAR_TRACKING
+  return 0;
+}
+
+
+bool
+Item_func_set_user_var::update_hash(void *ptr, size_t length,
+                                    Item_result res_type,
+                                    CHARSET_INFO *cs,
+                                    bool unsigned_arg)
+{
+  /*
+    If we set a variable explicitly to NULL then keep the old
+    result type of the variable
+  */
+  if (args[0]->type() == Item::FIELD_ITEM)
+  {
+    /* args[0]->null_value may be outdated */
+    null_value= ((Item_field*)args[0])->field->is_null();
+  }
+  else
+    null_value= args[0]->null_value;
+  if (null_value && null_item)
+    res_type= m_var_entry->type;                 // Don't change type of item
+  if (::update_hash(m_var_entry, null_value,
+                    ptr, length, res_type, cs, unsigned_arg))
+  {
+    null_value= 1;
+    return 1;
+  }
+  return 0;
+}
+
+
+/** Get the value of a variable as a double. */
+
+double user_var_entry::val_real(bool *null_value)
+{
+  if ((*null_value= (value == 0)))
+    return 0.0;
+
+  switch (type) {
+  case REAL_RESULT:
+    return *(double*) value;
+  case INT_RESULT:
+    return (double) *(longlong*) value;
+  case DECIMAL_RESULT:
+    return ((my_decimal *)value)->to_double();
+  case STRING_RESULT:
+    return my_atof(value);                      // This is null terminated
+  case ROW_RESULT:
+  case TIME_RESULT:
+    DBUG_ASSERT(0);				// Impossible
+    break;
+  }
+  return 0.0;					// Impossible
+}
+
+
+/** Get the value of a variable as an integer. */
+
+longlong user_var_entry::val_int(bool *null_value) const
+{
+  if ((*null_value= (value == 0)))
+    return 0;
+
+  switch (type) {
+  case REAL_RESULT:
+    return (longlong) *(double*) value;
+  case INT_RESULT:
+    return *(longlong*) value;
+  case DECIMAL_RESULT:
+    return ((my_decimal *)value)->to_longlong(false);
+  case STRING_RESULT:
+  {
+    int error;
+    return my_strtoll10(value, (char**) 0, &error);// String is null terminated
+  }
+  case ROW_RESULT:
+  case TIME_RESULT:
+    DBUG_ASSERT(0);				// Impossible
+    break;
+  }
+  return 0;					// Impossible
+}
+
+
+/** Get the value of a variable as a string. */
+
+String *user_var_entry::val_str(bool *null_value, String *str,
+                                uint decimals) const
+{
+  if ((*null_value= (value == 0)))
+    return (String*) 0;
+
+  switch (type) {
+  case REAL_RESULT:
+    str->set_real(*(double*) value, decimals, charset());
+    break;
+  case INT_RESULT:
+    if (!unsigned_flag)
+      str->set(*(longlong*) value, charset());
+    else
+      str->set(*(ulonglong*) value, charset());
+    break;
+  case DECIMAL_RESULT:
+    str_set_decimal((my_decimal *) value, str, charset());
+    break;
+  case STRING_RESULT:
+    if (str->copy(value, length, charset()))
+      str= 0;					// EOM error
+    break;
+  case ROW_RESULT:
+  case TIME_RESULT:
+    DBUG_ASSERT(0);				// Impossible
+    break;
+  }
+  return(str);
+}
+
+/** Get the value of a variable as a decimal. */
+
+my_decimal *user_var_entry::val_decimal(bool *null_value, my_decimal *val)
+{
+  if ((*null_value= (value == 0)))
+    return 0;
+
+  switch (type) {
+  case REAL_RESULT:
+    double2my_decimal(E_DEC_FATAL_ERROR, *(double*) value, val);
+    break;
+  case INT_RESULT:
+    int2my_decimal(E_DEC_FATAL_ERROR, *(longlong*) value, 0, val);
+    break;
+  case DECIMAL_RESULT:
+    my_decimal2decimal((my_decimal *) value, val);
+    break;
+  case STRING_RESULT:
+    str2my_decimal(E_DEC_FATAL_ERROR, value, length, charset(), val);
+    break;
+  case ROW_RESULT:
+  case TIME_RESULT:
+    DBUG_ASSERT(0);				// Impossible
+    break;
+  }
+  return(val);
+}
+
+/**
+  This functions is invoked on SET \@variable or
+  \@variable:= expression.
+
+  Evaluate (and check expression), store results.
+
+  @note
+    For now it always return OK. All problem with value evaluating
+    will be caught by thd->is_error() check in sql_set_variables().
+
+  @retval
+    FALSE OK.
+*/
+
+bool
+Item_func_set_user_var::check(bool use_result_field)
+{
+  DBUG_ENTER("Item_func_set_user_var::check");
+  if (use_result_field && !result_field)
+    use_result_field= FALSE;
+
+  switch (result_type()) {
+  case REAL_RESULT:
+  {
+    save_result.vreal= use_result_field ? result_field->val_real() :
+                        args[0]->val_real();
+    break;
+  }
+  case INT_RESULT:
+  {
+    save_result.vint= use_result_field ? result_field->val_int() :
+                       args[0]->val_int();
+    unsigned_flag= (use_result_field ?
+                    ((Field_num*)result_field)->unsigned_flag:
+                    args[0]->unsigned_flag);
+    break;
+  }
+  case STRING_RESULT:
+  {
+    save_result.vstr= use_result_field ? result_field->val_str(&value) :
+                       args[0]->val_str(&value);
+    break;
+  }
+  case DECIMAL_RESULT:
+  {
+    save_result.vdec= use_result_field ?
+                       result_field->val_decimal(&decimal_buff) :
+                       args[0]->val_decimal(&decimal_buff);
+    break;
+  }
+  case ROW_RESULT:
+  case TIME_RESULT:
+    DBUG_ASSERT(0);                // This case should never be chosen
+    break;
+  }
+  DBUG_RETURN(FALSE);
+}
+
+
+/**
+  @brief Evaluate and store item's result.
+  This function is invoked on "SELECT ... INTO @var ...".
+  
+  @param    item    An item to get value from.
+*/
+
+void Item_func_set_user_var::save_item_result(Item *item)
+{
+  DBUG_ENTER("Item_func_set_user_var::save_item_result");
+
+  switch (args[0]->result_type()) {
+  case REAL_RESULT:
+    save_result.vreal= item->val_result();
+    break;
+  case INT_RESULT:
+    save_result.vint= item->val_int_result();
+    unsigned_flag= item->unsigned_flag;
+    break;
+  case STRING_RESULT:
+    save_result.vstr= item->str_result(&value);
+    break;
+  case DECIMAL_RESULT:
+    save_result.vdec= item->val_decimal_result(&decimal_buff);
+    break;
+  case ROW_RESULT:
+  case TIME_RESULT:
+    DBUG_ASSERT(0);                // This case should never be chosen
+    break;
+  }
+  DBUG_VOID_RETURN;
+}
+
+
+/**
+  This functions is invoked on
+  SET \@variable or \@variable:= expression.
+
+  @note
+    We have to store the expression as such in the variable, independent of
+    the value method used by the user
+
+  @retval
+    0	OK
+  @retval
+    1	EOM Error
+
+*/
+
+bool
+Item_func_set_user_var::update()
+{
+  bool res= 0;
+  DBUG_ENTER("Item_func_set_user_var::update");
+
+  switch (result_type()) {
+  case REAL_RESULT:
+  {
+    res= update_hash((void*) &save_result.vreal,sizeof(save_result.vreal),
+		     REAL_RESULT, &my_charset_numeric, 0);
+    break;
+  }
+  case INT_RESULT:
+  {
+    res= update_hash((void*) &save_result.vint, sizeof(save_result.vint),
+                     INT_RESULT, &my_charset_numeric, unsigned_flag);
+    break;
+  }
+  case STRING_RESULT:
+  {
+    if (!save_result.vstr)					// Null value
+      res= update_hash((void*) 0, 0, STRING_RESULT, &my_charset_bin, 0);
+    else
+      res= update_hash((void*) save_result.vstr->ptr(),
+		       save_result.vstr->length(), STRING_RESULT,
+		       save_result.vstr->charset(), 0);
+    break;
+  }
+  case DECIMAL_RESULT:
+  {
+    if (!save_result.vdec)					// Null value
+      res= update_hash((void*) 0, 0, DECIMAL_RESULT, &my_charset_bin, 0);
+    else
+      res= update_hash((void*) save_result.vdec,
+                       sizeof(my_decimal), DECIMAL_RESULT,
+                       &my_charset_numeric, 0);
+    break;
+  }
+  case ROW_RESULT:
+  case TIME_RESULT:
+    DBUG_ASSERT(0);                // This case should never be chosen
+    break;
+  }
+  DBUG_RETURN(res);
+}
+
+
+double Item_func_set_user_var::val_real()
+{
+  DBUG_ASSERT(fixed());
+  check(0);
+  update();					// Store expression
+  return m_var_entry->val_real(&null_value);
+}
+
+longlong Item_func_set_user_var::val_int()
+{
+  DBUG_ASSERT(fixed());
+  check(0);
+  update();					// Store expression
+  return m_var_entry->val_int(&null_value);
+}
+
+String *Item_func_set_user_var::val_str(String *str)
+{
+  DBUG_ASSERT(fixed());
+  check(0);
+  update();					// Store expression
+  return m_var_entry->val_str(&null_value, str, decimals);
+}
+
+
+my_decimal *Item_func_set_user_var::val_decimal(my_decimal *val)
+{
+  DBUG_ASSERT(fixed());
+  check(0);
+  update();					// Store expression
+  return m_var_entry->val_decimal(&null_value, val);
+}
+
+
+double Item_func_set_user_var::val_result()
+{
+  DBUG_ASSERT(fixed());
+  check(TRUE);
+  update();					// Store expression
+  return m_var_entry->val_real(&null_value);
+}
+
+longlong Item_func_set_user_var::val_int_result()
+{
+  DBUG_ASSERT(fixed());
+  check(TRUE);
+  update();					// Store expression
+  return m_var_entry->val_int(&null_value);
+}
+
+bool Item_func_set_user_var::val_bool_result()
+{
+  DBUG_ASSERT(fixed());
+  check(TRUE);
+  update();					// Store expression
+  return m_var_entry->val_int(&null_value) != 0;
+}
+
+String *Item_func_set_user_var::str_result(String *str)
+{
+  DBUG_ASSERT(fixed());
+  check(TRUE);
+  update();					// Store expression
+  return m_var_entry->val_str(&null_value, str, decimals);
+}
+
+
+my_decimal *Item_func_set_user_var::val_decimal_result(my_decimal *val)
+{
+  DBUG_ASSERT(fixed());
+  check(TRUE);
+  update();					// Store expression
+  return m_var_entry->val_decimal(&null_value, val);
+}
+
+
+bool Item_func_set_user_var::is_null_result()
+{
+  DBUG_ASSERT(fixed());
+  check(TRUE);
+  update();					// Store expression
+  return is_null();
+}
+
+
+void Item_func_set_user_var::print(String *str, enum_query_type query_type)
+{
+  str->append(STRING_WITH_LEN("@"));
+  str->append(&name);
+  str->append(STRING_WITH_LEN(":="));
+  args[0]->print_parenthesised(str, query_type, precedence());
+}
+
+
+void Item_func_set_user_var::print_as_stmt(String *str,
+                                           enum_query_type query_type)
+{
+  str->append(STRING_WITH_LEN("set @"));
+  str->append(&name);
+  str->append(STRING_WITH_LEN(":="));
+  args[0]->print_parenthesised(str, query_type, precedence());
+}
+
+bool Item_func_set_user_var::send(Protocol *protocol, st_value *buffer)
+{
+  if (result_field)
+  {
+    check(1);
+    update();
+    return protocol->store(result_field);
+  }
+  return Item::send(protocol, buffer);
+}
+
+void Item_func_set_user_var::make_send_field(THD *thd, Send_field *tmp_field)
+{
+  if (result_field)
+  {
+    result_field->make_send_field(tmp_field);
+    DBUG_ASSERT(tmp_field->table_name.str != 0);
+    if (Item::name.str)
+      tmp_field->col_name= Item::name;          // Use user supplied name
+  }
+  else
+    Item::make_send_field(thd, tmp_field);
+}
+
+
+/*
+  Save the value of a user variable into a field
+
+  SYNOPSIS
+    save_in_field()
+      field           target field to save the value to
+      no_conversion   flag indicating whether conversions are allowed
+
+  DESCRIPTION
+    Save the function value into a field and update the user variable
+    accordingly. If a result field is defined and the target field doesn't
+    coincide with it then the value from the result field will be used as
+    the new value of the user variable.
+
+    The reason to have this method rather than simply using the result
+    field in the val_xxx() methods is that the value from the result field
+    not always can be used when the result field is defined.
+    Let's consider the following cases:
+    1) when filling a tmp table the result field is defined but the value of it
+    is undefined because it has to be produced yet. Thus we can't use it.
+    2) on execution of an INSERT ... SELECT statement the save_in_field()
+    function will be called to fill the data in the new record. If the SELECT
+    part uses a tmp table then the result field is defined and should be
+    used in order to get the correct result.
+
+    The difference between the SET_USER_VAR function and regular functions
+    like CONCAT is that the Item_func objects for the regular functions are
+    replaced by Item_field objects after the values of these functions have
+    been stored in a tmp table. Yet an object of the Item_field class cannot
+    be used to update a user variable.
+    Due to this we have to handle the result field in a special way here and
+    in the Item_func_set_user_var::send() function.
+
+  RETURN VALUES
+    FALSE       Ok
+    TRUE        Error
+*/
+
+int Item_func_set_user_var::save_in_field(Field *field, bool no_conversions,
+                                          bool can_use_result_field)
+{
+  bool use_result_field= (!can_use_result_field ? 0 :
+                          (result_field && result_field != field));
+  int error;
+
+  /* Update the value of the user variable */
+  check(use_result_field);
+  update();
+
+  if (result_type() == STRING_RESULT ||
+      (result_type() == REAL_RESULT &&
+       field->result_type() == STRING_RESULT))
+  {
+    String *result;
+    CHARSET_INFO *cs= collation.collation;
+    char buff[MAX_FIELD_WIDTH];		// Alloc buffer for small columns
+    str_value.set_buffer_if_not_allocated(buff, sizeof(buff), cs);
+    result= m_var_entry->val_str(&null_value, &str_value, decimals);
+
+    if (null_value)
+    {
+      str_value.set_buffer_if_not_allocated(0, 0, cs);
+      return set_field_to_null_with_conversions(field, no_conversions);
+    }
+
+    /* NOTE: If null_value == FALSE, "result" must be not NULL.  */
+
+    field->set_notnull();
+    error=field->store(result->ptr(),result->length(),cs);
+    str_value.set_buffer_if_not_allocated(0, 0, cs);
+  }
+  else if (result_type() == REAL_RESULT)
+  {
+    double nr= m_var_entry->val_real(&null_value);
+    if (null_value)
+      return set_field_to_null(field);
+    field->set_notnull();
+    error=field->store(nr);
+  }
+  else if (result_type() == DECIMAL_RESULT)
+  {
+    my_decimal decimal_value;
+    my_decimal *val= m_var_entry->val_decimal(&null_value, &decimal_value);
+    if (null_value)
+      return set_field_to_null(field);
+    field->set_notnull();
+    error=field->store_decimal(val);
+  }
+  else
+  {
+    longlong nr= m_var_entry->val_int(&null_value);
+    if (null_value)
+      return set_field_to_null_with_conversions(field, no_conversions);
+    field->set_notnull();
+    error=field->store(nr, unsigned_flag);
+  }
+  return error;
+}
+
+
+String *
+Item_func_get_user_var::val_str(String *str)
+{
+  DBUG_ASSERT(fixed());
+  DBUG_ENTER("Item_func_get_user_var::val_str");
+  if (!m_var_entry)
+    DBUG_RETURN((String*) 0);			// No such variable
+  DBUG_RETURN(m_var_entry->val_str(&null_value, str, decimals));
+}
+
+
+double Item_func_get_user_var::val_real()
+{
+  DBUG_ASSERT(fixed());
+  if (!m_var_entry)
+    return 0.0;					// No such variable
+  return (m_var_entry->val_real(&null_value));
+}
+
+
+my_decimal *Item_func_get_user_var::val_decimal(my_decimal *dec)
+{
+  DBUG_ASSERT(fixed());
+  if (!m_var_entry)
+    return 0;
+  return m_var_entry->val_decimal(&null_value, dec);
+}
+
+
+longlong Item_func_get_user_var::val_int()
+{
+  DBUG_ASSERT(fixed());
+  if (!m_var_entry)
+    return 0;				// No such variable
+  return (m_var_entry->val_int(&null_value));
+}
+
+
+/**
+  Get variable by name and, if necessary, put the record of variable 
+  use into the binary log.
+
+  When a user variable is invoked from an update query (INSERT, UPDATE etc),
+  stores this variable and its value in thd->user_var_events, so that it can be
+  written to the binlog (will be written just before the query is written, see
+  log.cc).
+
+  @param      thd        Current thread
+  @param      name       Variable name
+  @param[out] out_entry  variable structure or NULL. The pointer is set
+                         regardless of whether function succeeded or not.
+
+  @retval
+    0  OK
+  @retval
+    1  Failed to put appropriate record into binary log
+
+*/
+
+static int
+get_var_with_binlog(THD *thd, enum_sql_command sql_command,
+                    LEX_CSTRING *name, user_var_entry **out_entry)
+{
+  BINLOG_USER_VAR_EVENT *user_var_event;
+  user_var_entry *var_entry;
+  var_entry= get_variable(&thd->user_vars, name, 0);
+
+  /*
+    Any reference to user-defined variable which is done from stored
+    function or trigger affects their execution and the execution of the
+    calling statement. We must log all such variables even if they are 
+    not involved in table-updating statements.
+  */
+  if (!(opt_bin_log && 
+       (is_update_query(sql_command) || thd->in_sub_stmt)))
+  {
+    *out_entry= var_entry;
+    return 0;
+  }
+
+  if (!var_entry)
+  {
+    /*
+      If the variable does not exist, it's NULL, but we want to create it so
+      that it gets into the binlog (if it didn't, the slave could be
+      influenced by a variable of the same name previously set by another
+      thread).
+      We create it like if it had been explicitly set with SET before.
+      The 'new' mimics what sql_yacc.yy does when 'SET @a=10;'.
+      sql_set_variables() is what is called from 'case SQLCOM_SET_OPTION'
+      in dispatch_command()). Instead of building a one-element list to pass to
+      sql_set_variables(), we could instead manually call check() and update();
+      this would save memory and time; but calling sql_set_variables() makes
+      one unique place to maintain (sql_set_variables()). 
+
+      Manipulation with lex is necessary since free_underlaid_joins
+      is going to release memory belonging to the main query.
+    */
+
+    List<set_var_base> tmp_var_list;
+    LEX *sav_lex= thd->lex, lex_tmp;
+    thd->lex= &lex_tmp;
+    lex_start(thd);
+    tmp_var_list.push_back(new (thd->mem_root)
+                           set_var_user(new (thd->mem_root)
+                                        Item_func_set_user_var(thd, name,
+                                                               new (thd->mem_root) Item_null(thd))),
+                           thd->mem_root);
+    /* Create the variable if the above allocations succeeded */
+    if (unlikely(thd->is_fatal_error) ||
+        unlikely(sql_set_variables(thd, &tmp_var_list, false)))
+    {
+      thd->lex= sav_lex;
+      goto err;
+    }
+    thd->lex= sav_lex;
+    if (unlikely(!(var_entry= get_variable(&thd->user_vars, name, 0))))
+      goto err;
+  }
+  else if (var_entry->used_query_id == thd->query_id ||
+           mysql_bin_log.is_query_in_union(thd, var_entry->used_query_id))
+  {
+    /* 
+       If this variable was already stored in user_var_events by this query
+       (because it's used in more than one place in the query), don't store
+       it.
+    */
+    *out_entry= var_entry;
+    return 0;
+  }
+
+  size_t size;
+  /*
+    First we need to store value of var_entry, when the next situation
+    appears:
+    > set @a:=1;
+    > insert into t1 values (@a), (@a:=@a+1), (@a:=@a+1);
+    We have to write to binlog value @a= 1.
+
+    We allocate the user_var_event on user_var_events_alloc pool, not on
+    the this-statement-execution pool because in SPs user_var_event objects 
+    may need to be valid after current [SP] statement execution pool is
+    destroyed.
+  */
+  size= ALIGN_SIZE(sizeof(BINLOG_USER_VAR_EVENT)) + var_entry->length;
+  if (unlikely(!(user_var_event= (BINLOG_USER_VAR_EVENT *)
+                 alloc_root(thd->user_var_events_alloc, size))))
+    goto err;
+
+  user_var_event->value= (char*) user_var_event +
+    ALIGN_SIZE(sizeof(BINLOG_USER_VAR_EVENT));
+  user_var_event->user_var_event= var_entry;
+  user_var_event->type= var_entry->type;
+  user_var_event->charset_number= var_entry->charset()->number;
+  user_var_event->unsigned_flag= var_entry->unsigned_flag;
+  if (!var_entry->value)
+  {
+    /* NULL value*/
+    user_var_event->length= 0;
+    user_var_event->value= 0;
+  }
+  else
+  {
+    user_var_event->length= var_entry->length;
+    memcpy(user_var_event->value, var_entry->value,
+           var_entry->length);
+  }
+  /* Mark that this variable has been used by this query */
+  var_entry->used_query_id= thd->query_id;
+  if (insert_dynamic(&thd->user_var_events, (uchar*) &user_var_event))
+    goto err;
+
+  *out_entry= var_entry;
+  return 0;
+
+err:
+  *out_entry= var_entry;
+  return 1;
+}
+
+bool Item_func_get_user_var::fix_length_and_dec(THD *thd)
+{
+  int error;
+  set_maybe_null();
+  decimals=NOT_FIXED_DEC;
+  max_length=MAX_BLOB_WIDTH;
+
+  error= get_var_with_binlog(thd, thd->lex->sql_command, &name, &m_var_entry);
+
+  /*
+    If the variable didn't exist it has been created as a STRING-type.
+    'm_var_entry' is NULL only if there occurred an error during the call to
+    get_var_with_binlog.
+  */
+  if (likely(!error && m_var_entry))
+  {
+    unsigned_flag= m_var_entry->unsigned_flag;
+    max_length= (uint32)m_var_entry->length;
+    switch (m_var_entry->type) {
+    case REAL_RESULT:
+      collation.set(&my_charset_numeric, DERIVATION_NUMERIC);
+      fix_char_length(DBL_DIG + 8);
+      set_handler(&type_handler_double);
+      break;
+    case INT_RESULT:
+      collation.set(&my_charset_numeric, DERIVATION_NUMERIC);
+      fix_char_length(MAX_BIGINT_WIDTH);
+      decimals=0;
+      if (unsigned_flag)
+        set_handler(&type_handler_ulonglong);
+      else
+        set_handler(&type_handler_slonglong);
+      break;
+    case STRING_RESULT:
+      collation.set(m_var_entry->charset(), DERIVATION_IMPLICIT);
+      max_length= MAX_BLOB_WIDTH - 1;
+      set_handler(&type_handler_long_blob);
+      break;
+    case DECIMAL_RESULT:
+      collation.set(&my_charset_numeric, DERIVATION_NUMERIC);
+      fix_char_length(DECIMAL_MAX_STR_LENGTH);
+      decimals= DECIMAL_MAX_SCALE;
+      set_handler(&type_handler_newdecimal);
+      break;
+    case ROW_RESULT:                            // Keep compiler happy
+    case TIME_RESULT:
+      DBUG_ASSERT(0);                // This case should never be chosen
+      break;
+    }
+  }
+  else
+  {
+    collation.set(&my_charset_bin, DERIVATION_IMPLICIT);
+    null_value= 1;
+    set_handler(&type_handler_long_blob);
+    max_length= MAX_BLOB_WIDTH;
+  }
+  return false;
+}
+
+
+bool Item_func_get_user_var::const_item() const
+{
+  return (!m_var_entry ||
+          current_thd->query_id != m_var_entry->update_query_id);
+}
+
+
+void Item_func_get_user_var::print(String *str, enum_query_type query_type)
+{
+  str->append(STRING_WITH_LEN("@"));
+  append_identifier(current_thd, str, &name);
+}
+
+
+bool Item_func_get_user_var::eq(const Item *item, bool binary_cmp) const
+{
+  /* Assume we don't have rtti */
+  if (this == item)
+    return 1;					// Same item is same.
+  /* Check if other type is also a get_user_var() object */
+  if (item->type() != FUNC_ITEM ||
+      ((Item_func*) item)->functype() != functype())
+    return 0;
+  Item_func_get_user_var *other=(Item_func_get_user_var*) item;
+  return (name.length == other->name.length &&
+	  !memcmp(name.str, other->name.str, name.length));
+}
+
+
+bool Item_func_get_user_var::set_value(THD *thd,
+                                       sp_rcontext * /*ctx*/, Item **it)
+{
+  LEX_CSTRING tmp_name= get_name();
+  Item_func_set_user_var *suv= new (thd->mem_root) Item_func_set_user_var(thd, &tmp_name, *it);
+  /*
+    Item_func_set_user_var is not fixed after construction, call
+    fix_fields().
+  */
+  return (!suv || suv->fix_fields(thd, it) || suv->check(0) || suv->update());
+}
+
+
+bool Item_user_var_as_out_param::fix_fields(THD *thd, Item **ref)
+{
+  DBUG_ASSERT(!fixed());
+  DBUG_ASSERT(thd->lex->exchange);
+  if (!(entry= get_variable(&thd->user_vars, &org_name, 1)))
+    return TRUE;
+  entry->type= STRING_RESULT;
+  /*
+    Let us set the same collation which is used for loading
+    of fields in LOAD DATA INFILE.
+    (Since Item_user_var_as_out_param is used only there).
+  */
+  entry->set_charset(thd->lex->exchange->cs ?
+                     thd->lex->exchange->cs :
+                     thd->variables.collation_database);
+  entry->update_query_id= thd->query_id;
+  return FALSE;
+}
+
+
+void Item_user_var_as_out_param::set_null_value(CHARSET_INFO* cs)
+{
+  ::update_hash(entry, TRUE, 0, 0, STRING_RESULT, cs, 0 /* unsigned_arg */);
+}
+
+
+void Item_user_var_as_out_param::set_value(const char *str, uint length,
+                                           CHARSET_INFO* cs)
+{
+  ::update_hash(entry, FALSE, (void*)str, length, STRING_RESULT, cs,
+                0 /* unsigned_arg */);
+}
+
+
+double Item_user_var_as_out_param::val_real()
+{
+  DBUG_ASSERT(0);
+  return 0.0;
+}
+
+
+longlong Item_user_var_as_out_param::val_int()
+{
+  DBUG_ASSERT(0);
+  return 0;
+}
+
+
+String* Item_user_var_as_out_param::val_str(String *str)
+{
+  DBUG_ASSERT(0);
+  return 0;
+}
+
+
+my_decimal* Item_user_var_as_out_param::val_decimal(my_decimal *decimal_buffer)
+{
+  DBUG_ASSERT(0);
+  return 0;
+}
+
+
+bool Item_user_var_as_out_param::get_date(THD *thd, MYSQL_TIME *ltime,
+                                          date_mode_t fuzzydate)
+{
+  DBUG_ASSERT(0);
+  return true;
+}
+
+
+void Item_user_var_as_out_param::load_data_print_for_log_event(THD *thd,
+                                                               String *str)
+                                                               const
+{
+  str->append('@');
+  append_identifier(thd, str, &org_name);
+}
+
+
+Item_func_get_system_var::
+Item_func_get_system_var(THD *thd, sys_var *var_arg, enum_var_type var_type_arg,
+                       LEX_CSTRING *component_arg, const char *name_arg,
+                       size_t name_len_arg):
+  Item_func(thd), var(var_arg), var_type(var_type_arg),
+  orig_var_type(var_type_arg), component(*component_arg), cache_present(0)
+{
+  /* set_name() will allocate the name */
+  set_name(thd, name_arg, (uint) name_len_arg, system_charset_info);
+}
+
+
+bool Item_func_get_system_var::is_written_to_binlog()
+{
+  return var->is_written_to_binlog(var_type);
+}
+
+
+void Item_func_get_system_var::update_null_value()
+{
+  THD *thd= current_thd;
+  int save_no_errors= thd->no_errors;
+  thd->no_errors= TRUE;
+  type_handler()->Item_update_null_value(this);
+  thd->no_errors= save_no_errors;
+}
+
+
+bool Item_func_get_system_var::fix_length_and_dec(THD *thd)
+{
+  const char *cptr;
+  set_maybe_null();
+  max_length= 0;
+
+  if (var->check_type(var_type))
+  {
+    if (var_type != OPT_DEFAULT)
+    {
+      my_error(ER_INCORRECT_GLOBAL_LOCAL_VAR, MYF(0),
+               var->name.str, var_type == OPT_GLOBAL ? "SESSION" : "GLOBAL");
+      return TRUE;
+    }
+    /* As there was no local variable, return the global value */
+    var_type= OPT_GLOBAL;
+  }
+
+  switch (var->show_type())
+  {
+    case SHOW_HA_ROWS:
+    case SHOW_UINT:
+    case SHOW_ULONG:
+    case SHOW_ULONGLONG:
+      unsigned_flag= TRUE;
+      /* fall through */
+    case SHOW_SINT:
+    case SHOW_SLONG:
+    case SHOW_SLONGLONG:
+      collation= DTCollation_numeric();
+      fix_char_length(MY_INT64_NUM_DECIMAL_DIGITS);
+      decimals=0;
+      break;
+    case SHOW_CHAR:
+    case SHOW_CHAR_PTR:
+      mysql_mutex_lock(&LOCK_global_system_variables);
+      cptr= var->show_type() == SHOW_CHAR ?
+          reinterpret_cast<const char*>(var->value_ptr(thd, var_type,
+                                                       &component)) :
+          *reinterpret_cast<const char* const*>(var->value_ptr(thd,
+                                                               var_type,
+                                                               &component));
+      if (cptr)
+        max_length= (uint32) system_charset_info->numchars(cptr,
+                                                           cptr + strlen(cptr));
+      mysql_mutex_unlock(&LOCK_global_system_variables);
+      collation.set(system_charset_info, DERIVATION_SYSCONST);
+      max_length*= system_charset_info->mbmaxlen;
+      decimals=NOT_FIXED_DEC;
+      break;
+    case SHOW_LEX_STRING:
+      {
+        mysql_mutex_lock(&LOCK_global_system_variables);
+        const LEX_STRING *ls=
+                reinterpret_cast<const LEX_STRING*>(var->value_ptr(current_thd,
+                                                                   var_type,
+                                                                   &component));
+        max_length= (uint32) system_charset_info->numchars(ls->str,
+                                                           ls->str + ls->length);
+        mysql_mutex_unlock(&LOCK_global_system_variables);
+        collation.set(system_charset_info, DERIVATION_SYSCONST);
+        max_length*= system_charset_info->mbmaxlen;
+        decimals=NOT_FIXED_DEC;
+      }
+      break;
+    case SHOW_BOOL:
+    case SHOW_MY_BOOL:
+      collation= DTCollation_numeric();
+      fix_char_length(1);
+      decimals=0;
+      break;
+    case SHOW_DOUBLE:
+      decimals= 6;
+      collation= DTCollation_numeric();
+      fix_char_length(DBL_DIG + 6);
+      break;
+    default:
+      my_error(ER_VAR_CANT_BE_READ, MYF(0), var->name.str);
+      break;
+  }
+  return FALSE;
+}
+
+
+void Item_func_get_system_var::print(String *str, enum_query_type query_type)
+{
+  if (name.length)
+    str->append(&name);
+  else
+  {
+    str->append(STRING_WITH_LEN("@@"));
+    if (component.length)
+    {
+      str->append(&component);
+      str->append('.');
+    }
+    else if (var_type == SHOW_OPT_GLOBAL && var->scope() != sys_var::GLOBAL)
+    {
+      str->append(STRING_WITH_LEN("global."));
+    }
+    str->append(&var->name);
+  }
+}
+
+bool Item_func_get_system_var::check_vcol_func_processor(void *arg)
+{
+  return mark_unsupported_function("@@", var->name.str, arg, VCOL_SESSION_FUNC);
+}
+
+
+const Type_handler *Item_func_get_system_var::type_handler() const
+{
+  switch (var->show_type())
+  {
+    case SHOW_BOOL:
+    case SHOW_MY_BOOL:
+    case SHOW_SINT:
+    case SHOW_SLONG:
+    case SHOW_SLONGLONG:
+      return &type_handler_slonglong;
+    case SHOW_UINT:
+    case SHOW_ULONG:
+    case SHOW_ULONGLONG:
+    case SHOW_HA_ROWS:
+      return &type_handler_ulonglong;
+    case SHOW_CHAR: 
+    case SHOW_CHAR_PTR: 
+    case SHOW_LEX_STRING:
+      return &type_handler_varchar;
+    case SHOW_DOUBLE:
+      return &type_handler_double;
+    default:
+      my_error(ER_VAR_CANT_BE_READ, MYF(0), var->name.str);
+      return &type_handler_varchar;              // keep the compiler happy
+  }
+}
+
+
+longlong Item_func_get_system_var::val_int()
+{
+  THD *thd= current_thd;
+
+  DBUG_EXECUTE_IF("simulate_non_gtid_aware_master",
+                  {
+                    if (0 == strcmp("gtid_domain_id", var->name.str))
+                    {
+                      my_error(ER_VAR_CANT_BE_READ, MYF(0), var->name.str);
+                      return 0;
+                    }
+                  });
+  if (cache_present && thd->query_id == used_query_id)
+  {
+    if (cache_present & GET_SYS_VAR_CACHE_LONG)
+    {
+      null_value= cached_null_value;
+      return cached_llval;
+    } 
+    else if (cache_present & GET_SYS_VAR_CACHE_DOUBLE)
+    {
+      null_value= cached_null_value;
+      cached_llval= (longlong) cached_dval;
+      cache_present|= GET_SYS_VAR_CACHE_LONG;
+      return cached_llval;
+    }
+    else if (cache_present & GET_SYS_VAR_CACHE_STRING)
+    {
+      null_value= cached_null_value;
+      if (!null_value)
+        cached_llval= longlong_from_string_with_check(&cached_strval);
+      else
+        cached_llval= 0;
+      cache_present|= GET_SYS_VAR_CACHE_LONG;
+      return cached_llval;
+    }
+  }
+
+  cached_llval= var->val_int(&null_value, thd, var_type, &component);
+  cache_present |= GET_SYS_VAR_CACHE_LONG;
+  used_query_id= thd->query_id;
+  cached_null_value= null_value;
+  return cached_llval;
+}
+
+
+String* Item_func_get_system_var::val_str(String* str)
+{
+  THD *thd= current_thd;
+
+  if (cache_present && thd->query_id == used_query_id)
+  {
+    if (cache_present & GET_SYS_VAR_CACHE_STRING)
+    {
+      null_value= cached_null_value;
+      return null_value ? NULL : &cached_strval;
+    }
+    else if (cache_present & GET_SYS_VAR_CACHE_LONG)
+    {
+      null_value= cached_null_value;
+      if (!null_value)
+        cached_strval.set (cached_llval, collation.collation);
+      cache_present|= GET_SYS_VAR_CACHE_STRING;
+      return null_value ? NULL : &cached_strval;
+    }
+    else if (cache_present & GET_SYS_VAR_CACHE_DOUBLE)
+    {
+      null_value= cached_null_value;
+      if (!null_value)
+        cached_strval.set_real (cached_dval, decimals, collation.collation);
+      cache_present|= GET_SYS_VAR_CACHE_STRING;
+      return null_value ? NULL : &cached_strval;
+    }
+  }
+
+  str= var->val_str(&cached_strval, thd, var_type, &component);
+  cache_present|= GET_SYS_VAR_CACHE_STRING;
+  used_query_id= thd->query_id;
+  cached_null_value= null_value= !str;
+  return str;
+}
+
+
+double Item_func_get_system_var::val_real()
+{
+  THD *thd= current_thd;
+
+  if (cache_present && thd->query_id == used_query_id)
+  {
+    if (cache_present & GET_SYS_VAR_CACHE_DOUBLE)
+    {
+      null_value= cached_null_value;
+      return cached_dval;
+    }
+    else if (cache_present & GET_SYS_VAR_CACHE_LONG)
+    {
+      null_value= cached_null_value;
+      cached_dval= (double)cached_llval;
+      cache_present|= GET_SYS_VAR_CACHE_DOUBLE;
+      return cached_dval;
+    }
+    else if (cache_present & GET_SYS_VAR_CACHE_STRING)
+    {
+      null_value= cached_null_value;
+      if (!null_value)
+        cached_dval= double_from_string_with_check(&cached_strval);
+      else
+        cached_dval= 0;
+      cache_present|= GET_SYS_VAR_CACHE_DOUBLE;
+      return cached_dval;
+    }
+  }
+
+  cached_dval= var->val_real(&null_value, thd, var_type, &component);
+  cache_present |= GET_SYS_VAR_CACHE_DOUBLE;
+  used_query_id= thd->query_id;
+  cached_null_value= null_value;
+  return cached_dval;
+}
+
+
+bool Item_func_get_system_var::eq(const Item *item, bool binary_cmp) const
+{
+  /* Assume we don't have rtti */
+  if (this == item)
+    return 1;					// Same item is same.
+  /* Check if other type is also a get_user_var() object */
+  if (item->type() != FUNC_ITEM ||
+      ((Item_func*) item)->functype() != functype())
+    return 0;
+  Item_func_get_system_var *other=(Item_func_get_system_var*) item;
+  return (var == other->var && var_type == other->var_type);
+}
+
+
+void Item_func_get_system_var::cleanup()
+{
+  Item_func::cleanup();
+  cache_present= 0;
+  var_type= orig_var_type;
+  cached_strval.free();
+}
+
+/**
+   @retval
+   0 ok
+   1 OOM error
+*/
+
+bool Item_func_match::init_search(THD *thd, bool no_order)
+{
+  DBUG_ENTER("Item_func_match::init_search");
+
+  if (!table->file->is_open())
+    DBUG_RETURN(0);
+
+  /* Check if init_search() has been called before */
+  if (ft_handler)
+  {
+    if (join_key)
+      table->file->ft_handler= ft_handler;
+    DBUG_RETURN(0);
+  }
+
+  if (key == NO_SUCH_KEY)
+  {
+    List<Item> fields;
+    fields.push_back(new (thd->mem_root)
+                     Item_string(thd, " ", 1, cmp_collation.collation),
+                     thd->mem_root);
+    for (uint i= 1; i < arg_count; i++)
+      fields.push_back(args[i]);
+    concat_ws= new (thd->mem_root) Item_func_concat_ws(thd, fields);
+    if (unlikely(thd->is_fatal_error))
+      DBUG_RETURN(1);                           // OOM in new or push_back
+    /*
+      Above function used only to get value and do not need fix_fields for it:
+      Item_string - basic constant
+      fields - fix_fields() was already called for this arguments
+      Item_func_concat_ws - do not need fix_fields() to produce value
+    */
+    concat_ws->quick_fix_field();
+  }
+
+  if (master)
+  {
+    join_key= master->join_key= join_key | master->join_key;
+    if (master->init_search(thd, no_order))
+      DBUG_RETURN(1);
+    ft_handler= master->ft_handler;
+    join_key= master->join_key;
+    DBUG_RETURN(0);
+  }
+
+  String *ft_tmp= 0;
+
+  // MATCH ... AGAINST (NULL) is meaningless, but possible
+  if (!(ft_tmp=key_item()->val_str(&value)))
+  {
+    ft_tmp= &value;
+    value.set("", 0, cmp_collation.collation);
+  }
+
+  if (ft_tmp->charset() != cmp_collation.collation)
+  {
+    uint dummy_errors;
+    if (search_value.copy(ft_tmp->ptr(), ft_tmp->length(), ft_tmp->charset(),
+                          cmp_collation.collation, &dummy_errors))
+      DBUG_RETURN(1);
+    ft_tmp= &search_value;
+  }
+
+  if (join_key && !no_order)
+    match_flags|=FT_SORTED;
+
+  if (key != NO_SUCH_KEY)
+    THD_STAGE_INFO(table->in_use, stage_fulltext_initialization);
+
+  ft_handler= table->file->ft_init_ext(match_flags, key, ft_tmp);
+
+  if (!ft_handler)
+    DBUG_RETURN(1);
+  if (join_key)
+    table->file->ft_handler=ft_handler;
+
+  DBUG_RETURN(0);
+}
+
+
+bool Item_func_match::fix_fields(THD *thd, Item **ref)
+{
+  DBUG_ASSERT(fixed() == 0);
+  Item *UNINIT_VAR(item);                        // Safe as arg_count is > 1
+
+  status_var_increment(thd->status_var.feature_fulltext);
+
+  set_maybe_null();
+  join_key=0;
+
+  /*
+    const_item is assumed in quite a bit of places, so it would be difficult
+    to remove;  If it would ever to be removed, this should include
+    modifications to find_best and auto_close as complement to auto_init code
+    above.
+   */
+  if (Item_func::fix_fields(thd, ref) ||
+      !args[0]->const_during_execution())
+  {
+    my_error(ER_WRONG_ARGUMENTS,MYF(0),"AGAINST");
+    return TRUE;
+  }
+
+  bool allows_multi_table_search= true;
+  const_item_cache=0;
+  table= 0;
+  for (uint i=1 ; i < arg_count ; i++)
+  {
+
+    item= args[i]->real_item();
+    /*
+      When running in PS mode, some Item_field's can already be replaced
+      to Item_func_conv_charset during PREPARE time. This is possible
+      in case of "MATCH (f1,..,fN) AGAINST (... IN BOOLEAN MODE)"
+      when running without any fulltext indexes and when fields f1..fN
+      have different character sets.
+      So we check for FIELD_ITEM only during prepare time and in non-PS mode,
+      and do not check in PS execute time.
+    */
+    if (!thd->stmt_arena->is_stmt_execute() &&
+        item->type() != Item::FIELD_ITEM)
+    {
+      my_error(ER_WRONG_ARGUMENTS, MYF(0), "MATCH");
+      return TRUE;
+    }
+    /*
+      During the prepare-time execution of fix_fields() of a PS query some
+      Item_fields's could have been already replaced to Item_func_conv_charset
+      (by the call for agg_arg_charsets_for_comparison below()).
+      But agg_arg_charsets_for_comparison() is written in a way that
+      at least *one* of the Item_field's is not replaced.
+      This makes sure that "table" gets initialized during PS execution time.
+    */
+    if (item->type() == Item::FIELD_ITEM)
+      table= ((Item_field *)item)->field->table;
+
+    allows_multi_table_search &= allows_search_on_non_indexed_columns(table);
+  }
+
+  /*
+    Check that all columns come from the same table.
+    We've already checked that columns in MATCH are fields so
+    PARAM_TABLE_BIT can only appear from AGAINST argument.
+  */
+  if ((used_tables_cache & ~PARAM_TABLE_BIT) != item->used_tables())
+    key=NO_SUCH_KEY;
+
+  if (key == NO_SUCH_KEY && !allows_multi_table_search)
+  {
+    my_error(ER_WRONG_ARGUMENTS,MYF(0),"MATCH");
+    return TRUE;
+  }
+  if (!(table->file->ha_table_flags() & HA_CAN_FULLTEXT))
+  {
+    my_error(ER_TABLE_CANT_HANDLE_FT, MYF(0), table->file->table_type());
+    return 1;
+  }
+  table->fulltext_searched=1;
+  return agg_arg_charsets_for_comparison(cmp_collation, args+1, arg_count-1);
+}
+
+bool Item_func_match::fix_index()
+{
+  Item_field *item;
+  uint ft_to_key[MAX_KEY], ft_cnt[MAX_KEY], fts=0, keynr;
+  uint max_cnt=0, mkeys=0, i;
+
+  /*
+    We will skip execution if the item is not fixed
+    with fix_field
+  */
+  if (!fixed())
+    return false;
+
+  if (key == NO_SUCH_KEY)
+    return 0;
+  
+  if (!table) 
+    goto err;
+
+  for (keynr=0 ; keynr < table->s->keys ; keynr++)
+  {
+    if ((table->key_info[keynr].flags & HA_FULLTEXT) &&
+        (match_flags & FT_BOOL ?
+         table->keys_in_use_for_query.is_set(keynr) :
+         table->s->usable_indexes(table->in_use).is_set(keynr)))
+    {
+      ft_to_key[fts]=keynr;
+      ft_cnt[fts]=0;
+      fts++;
+    }
+  }
+
+  if (!fts)
+    goto err;
+
+  for (i=1; i < arg_count; i++)
+  {
+    Item *real_item= args[i]->real_item();
+    if (real_item->type() != FIELD_ITEM)
+      goto err;
+    item=(Item_field*)real_item;
+    for (keynr=0 ; keynr < fts ; keynr++)
+    {
+      KEY *ft_key=&table->key_info[ft_to_key[keynr]];
+      uint key_parts=ft_key->user_defined_key_parts;
+
+      for (uint part=0 ; part < key_parts ; part++)
+      {
+	if (item->field->eq(ft_key->key_part[part].field))
+	  ft_cnt[keynr]++;
+      }
+    }
+  }
+
+  for (keynr=0 ; keynr < fts ; keynr++)
+  {
+    if (ft_cnt[keynr] > max_cnt)
+    {
+      mkeys=0;
+      max_cnt=ft_cnt[mkeys]=ft_cnt[keynr];
+      ft_to_key[mkeys]=ft_to_key[keynr];
+      continue;
+    }
+    if (max_cnt && ft_cnt[keynr] == max_cnt)
+    {
+      mkeys++;
+      ft_cnt[mkeys]=ft_cnt[keynr];
+      ft_to_key[mkeys]=ft_to_key[keynr];
+      continue;
+    }
+  }
+
+  for (keynr=0 ; keynr <= mkeys ; keynr++)
+  {
+    // partial keys doesn't work
+    if (max_cnt < arg_count-1 ||
+        max_cnt < table->key_info[ft_to_key[keynr]].user_defined_key_parts)
+      continue;
+
+    key=ft_to_key[keynr];
+
+    return 0;
+  }
+
+err:
+  if (allows_search_on_non_indexed_columns(table))
+  {
+    key=NO_SUCH_KEY;
+    return 0;
+  }
+  my_message(ER_FT_MATCHING_KEY_NOT_FOUND,
+             ER(ER_FT_MATCHING_KEY_NOT_FOUND), MYF(0));
+  return 1;
+}
+
+
+bool Item_func_match::eq(const Item *item, bool binary_cmp) const
+{
+  if (item->type() != FUNC_ITEM ||
+      ((Item_func*)item)->functype() != FT_FUNC ||
+      match_flags != ((Item_func_match*)item)->match_flags)
+    return 0;
+
+  Item_func_match *ifm=(Item_func_match*) item;
+
+  if (key == ifm->key && table == ifm->table &&
+      key_item()->eq(ifm->key_item(), binary_cmp))
+    return 1;
+
+  return 0;
+}
+
+
+double Item_func_match::val_real()
+{
+  DBUG_ASSERT(fixed());
+  DBUG_ENTER("Item_func_match::val");
+  if (ft_handler == NULL)
+    DBUG_RETURN(-1.0);
+
+  if (key != NO_SUCH_KEY && table->null_row) /* NULL row from an outer join */
+    DBUG_RETURN(0.0);
+
+  if (join_key)
+  {
+    if (table->file->ft_handler)
+      DBUG_RETURN(ft_handler->please->get_relevance(ft_handler));
+    join_key=0;
+  }
+
+  if (key == NO_SUCH_KEY)
+  {
+    String *a= concat_ws->val_str(&value);
+    if ((null_value= (a == 0)) || !a->length())
+      DBUG_RETURN(0);
+    DBUG_RETURN(ft_handler->please->find_relevance(ft_handler,
+				      (uchar *)a->ptr(), a->length()));
+  }
+  DBUG_RETURN(ft_handler->please->find_relevance(ft_handler,
+                                                 table->record[0], 0));
+}
+
+void Item_func_match::print(String *str, enum_query_type query_type)
+{
+  str->append(STRING_WITH_LEN("(match "));
+  print_args(str, 1, query_type);
+  str->append(STRING_WITH_LEN(" against ("));
+  args[0]->print(str, query_type);
+  if (match_flags & FT_BOOL)
+    str->append(STRING_WITH_LEN(" in boolean mode"));
+  else if (match_flags & FT_EXPAND)
+    str->append(STRING_WITH_LEN(" with query expansion"));
+  str->append(STRING_WITH_LEN("))"));
+}
+
+
+class Func_handler_bit_xor_int_to_ulonglong:
+        public Item_handled_func::Handler_ulonglong
+{
+public:
+  Longlong_null to_longlong_null(Item_handled_func *item) const
+  {
+    DBUG_ASSERT(item->fixed());
+    return item->arguments()[0]->to_longlong_null() ^
+           item->arguments()[1]->to_longlong_null();
+  }
+};
+
+
+class Func_handler_bit_xor_dec_to_ulonglong:
+        public Item_handled_func::Handler_ulonglong
+{
+public:
+  Longlong_null to_longlong_null(Item_handled_func *item) const
+  {
+    DBUG_ASSERT(item->fixed());
+    return VDec(item->arguments()[0]).to_xlonglong_null() ^
+           VDec(item->arguments()[1]).to_xlonglong_null();
+  }
+};
+
+
+bool Item_func_bit_xor::fix_length_and_dec(THD *thd)
+{
+  static const Func_handler_bit_xor_int_to_ulonglong ha_int_to_ull;
+  static const Func_handler_bit_xor_dec_to_ulonglong ha_dec_to_ull;
+  return fix_length_and_dec_op2_std(&ha_int_to_ull, &ha_dec_to_ull);
+}
+
+
+/***************************************************************************
+  System variables
+****************************************************************************/
+
+/**
+  Return value of an system variable base[.name] as a constant item.
+
+  @param thd			Thread handler
+  @param var_type		global / session
+  @param name		        Name of base or system variable
+  @param component		Component.
+
+  @note
+    If component.str = 0 then the variable name is in 'name'
+
+  @return
+    - 0  : error
+    - #  : constant item
+*/
+
+
+Item *get_system_var(THD *thd, enum_var_type var_type,
+                     const LEX_CSTRING *name,
+		     const LEX_CSTRING *component)
+{
+  sys_var *var;
+  LEX_CSTRING base_name, component_name;
+
+  if (component->str)
+  {
+    base_name= *component;
+    component_name= *name;
+  }
+  else
+  {
+    base_name= *name;
+    component_name= *component;			// Empty string
+  }
+
+  if (!(var= find_sys_var(thd, base_name.str, base_name.length)))
+    return 0;
+  if (component->str)
+  {
+    if (!var->is_struct())
+    {
+      my_error(ER_VARIABLE_IS_NOT_STRUCT, MYF(0), base_name.str);
+      return 0;
+    }
+  }
+  thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);
+
+  set_if_smaller(component_name.length, MAX_SYS_VAR_LENGTH);
+
+  return new (thd->mem_root) Item_func_get_system_var(thd, var, var_type,
+                                                      &component_name,
+                                                      NULL, 0);
+}
+
+
+longlong Item_func_row_count::val_int()
+{
+  DBUG_ASSERT(fixed());
+  THD *thd= current_thd;
+
+  return thd->get_row_count_func();
+}
+
+
+
+
+Item_func_sp::Item_func_sp(THD *thd, Name_resolution_context *context_arg,
+                           sp_name *name, const Sp_handler *sph):
+  Item_func(thd), Item_sp(thd, context_arg, name), m_handler(sph)
+{
+  set_maybe_null();
+}
+
+
+Item_func_sp::Item_func_sp(THD *thd, Name_resolution_context *context_arg,
+                           sp_name *name_arg, const Sp_handler *sph,
+                           List<Item> &list):
+  Item_func(thd, list), Item_sp(thd, context_arg, name_arg), m_handler(sph)
+{
+  set_maybe_null();
+}
+
+
+void
+Item_func_sp::cleanup()
+{
+  Item_sp::cleanup();
+  Item_func::cleanup();
+}
+
+LEX_CSTRING
+Item_func_sp::func_name_cstring() const
+{
+  return Item_sp::func_name_cstring(current_thd,
+                                    m_handler == &sp_handler_package_function);
+}
+
+
+void my_missing_function_error(const LEX_CSTRING &token, const char *func_name)
+{
+  if (token.length && is_lex_native_function (&token))
+    my_error(ER_FUNC_INEXISTENT_NAME_COLLISION, MYF(0), func_name);
+  else
+    my_error(ER_SP_DOES_NOT_EXIST, MYF(0), "FUNCTION", func_name);
+}
+
+
+/**
+  @note
+  Deterministic stored procedures are considered inexpensive.
+  Consequently such procedures may be evaluated during optimization,
+  if they are constant (checked by the optimizer).
+*/
+
+bool Item_func_sp::is_expensive()
+{
+  return !m_sp->detistic() ||
+          current_thd->locked_tables_mode < LTM_LOCK_TABLES;
+}
+
+
+/**
+  @brief Initialize local members with values from the Field interface.
+
+  @note called from Item::fix_fields.
+*/
+
+bool Item_func_sp::fix_length_and_dec(THD *thd)
+{
+  DBUG_ENTER("Item_func_sp::fix_length_and_dec");
+
+  DBUG_ASSERT(sp_result_field);
+  Type_std_attributes::set(sp_result_field->type_std_attributes());
+  // There is a bug in the line below. See MDEV-11292 for details.
+  collation.derivation= DERIVATION_COERCIBLE;
+  set_maybe_null();
+
+  DBUG_RETURN(FALSE);
+}
+
+
+bool
+Item_func_sp::execute()
+{
+  /* Execute function and store the return value in the field. */
+  return Item_sp::execute(current_thd, &null_value, args, arg_count);
+}
+
+
+void
+Item_func_sp::make_send_field(THD *thd, Send_field *tmp_field)
+{
+  DBUG_ENTER("Item_func_sp::make_send_field");
+  DBUG_ASSERT(sp_result_field);
+  sp_result_field->make_send_field(tmp_field);
+  if (name.str)
+  {
+    DBUG_ASSERT(name.length == strlen(name.str));
+    tmp_field->col_name= name;
+  }
+  DBUG_VOID_RETURN;
+}
+
+
+const Type_handler *Item_func_sp::type_handler() const
+{
+  DBUG_ENTER("Item_func_sp::type_handler");
+  DBUG_PRINT("info", ("m_sp = %p", (void *) m_sp));
+  DBUG_ASSERT(sp_result_field);
+  // This converts ENUM/SET to STRING
+  const Type_handler *handler= sp_result_field->type_handler();
+  DBUG_RETURN(handler->type_handler_for_item_field());
+}
+
+
+longlong Item_func_found_rows::val_int()
+{
+  DBUG_ASSERT(fixed());
+  return current_thd->found_rows();
+}
+
+
+longlong Item_func_oracle_sql_rowcount::val_int()
+{
+  DBUG_ASSERT(fixed());
+  THD *thd= current_thd;
+  /*
+    In case when a query like this:
+      INSERT a INTO @va FROM t1;
+    returns multiple rows, SQL%ROWCOUNT should report 1 rather than -1.
+  */
+  longlong rows= thd->get_row_count_func();
+  return rows != -1 ? rows :                   // ROW_COUNT()
+                      thd->found_rows();       // FOUND_ROWS()
+}
+
+
+longlong Item_func_sqlcode::val_int()
+{
+  DBUG_ASSERT(fixed());
+  DBUG_ASSERT(!null_value);
+  Diagnostics_area::Sql_condition_iterator it=
+    current_thd->get_stmt_da()->sql_conditions();
+  const Sql_condition *err;
+  if ((err= it++))
+    return err->get_sql_errno();
+  return 0;
+}
+
+
+bool
+Item_func_sp::fix_fields(THD *thd, Item **ref)
+{
+  bool res;
+  DBUG_ENTER("Item_func_sp::fix_fields");
+  DBUG_ASSERT(fixed() == 0);
+  sp_head *sp= m_handler->sp_find_routine(thd, m_name, true);
+
+  /* 
+    Checking privileges to execute the function while creating view and
+    executing the function of select.
+   */
+  if (!(thd->lex->context_analysis_only & CONTEXT_ANALYSIS_ONLY_VIEW) ||
+      (thd->lex->sql_command == SQLCOM_CREATE_VIEW))
+  {
+    Security_context *save_security_ctx= thd->security_ctx;
+    if (context && context->security_ctx)
+      thd->security_ctx= context->security_ctx;
+
+    /*
+      If the routine is not found, let's still check EXECUTE_ACL to decide
+      whether to return "Access denied" or "Routine does not exist".
+    */
+    res= sp ? sp->check_execute_access(thd) :
+              check_routine_access(thd, EXECUTE_ACL, &m_name->m_db,
+                                   &m_name->m_name,
+                                   &sp_handler_function, false);
+    thd->security_ctx= save_security_ctx;
+
+    if (res)
+    {
+      process_error(thd);
+      DBUG_RETURN(res);
+    }
+  }
+
+
+  /* Custom aggregates are transformed into an Item_sum_sp. We can not do this
+     earlier as we have no way of knowing what kind of Item we should create
+     when parsing the query.
+
+     TODO(cvicentiu): See if this limitation can be lifted.
+  */
+
+  DBUG_ASSERT(m_sp == NULL);
+  if (!(m_sp= sp))
+  {
+    my_missing_function_error(m_name->m_name, ErrConvDQName(m_name).ptr());
+    process_error(thd);
+    DBUG_RETURN(TRUE);
+  }
+
+  /*
+    We must call init_result_field before Item_func::fix_fields()
+    to make m_sp and result_field members available to fix_length_and_dec(),
+    which is called from Item_func::fix_fields().
+  */
+  res= init_result_field(thd, max_length, maybe_null(), &null_value, &name);
+
+  if (res)
+    DBUG_RETURN(TRUE);
+
+  if (m_sp->agg_type() == GROUP_AGGREGATE)
+  {
+    Item_sum_sp *item_sp;
+    Query_arena *arena, backup;
+    arena= thd->activate_stmt_arena_if_needed(&backup);
+
+    if (arg_count)
+    {
+      List<Item> list;
+      for (uint i= 0; i < arg_count; i++)
+        list.push_back(args[i]);
+      item_sp= new (thd->mem_root) Item_sum_sp(thd, context, m_name, sp, list);
+    }
+    else
+      item_sp= new (thd->mem_root) Item_sum_sp(thd, context, m_name, sp);
+
+    if (arena)
+      thd->restore_active_arena(arena, &backup);
+    if (!item_sp)
+      DBUG_RETURN(TRUE);
+    *ref= item_sp;
+    item_sp->name= name;
+    bool err= item_sp->fix_fields(thd, ref);
+    if (err)
+      DBUG_RETURN(TRUE);
+
+    DBUG_RETURN(FALSE);
+  }
+
+  res= Item_func::fix_fields(thd, ref);
+
+  if (res)
+    DBUG_RETURN(TRUE);
+
+  if (thd->lex->is_view_context_analysis())
+  {
+    /*
+      Here we check privileges of the stored routine only during view
+      creation, in order to validate the view.  A runtime check is
+      performed in Item_func_sp::execute(), and this method is not
+      called during context analysis.  Notice, that during view
+      creation we do not infer into stored routine bodies and do not
+      check privileges of its statements, which would probably be a
+      good idea especially if the view has SQL SECURITY DEFINER and
+      the used stored procedure has SQL SECURITY DEFINER.
+    */
+    res= sp_check_access(thd);
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+    /*
+      Try to set and restore the security context to see whether it's valid
+    */
+    Security_context *save_secutiry_ctx;
+    res= set_routine_security_ctx(thd, m_sp, &save_secutiry_ctx);
+    if (!res)
+      m_sp->m_security_ctx.restore_security_context(thd, save_secutiry_ctx);
+    
+#endif /* ! NO_EMBEDDED_ACCESS_CHECKS */
+  }
+
+  if (!m_sp->detistic())
+  {
+    used_tables_cache |= RAND_TABLE_BIT;
+    const_item_cache= FALSE;
+  }
+
+  DBUG_RETURN(res);
+}
+
+
+void Item_func_sp::update_used_tables()
+{
+  Item_func::update_used_tables();
+
+  if (!m_sp->detistic())
+  {
+    used_tables_cache |= RAND_TABLE_BIT;
+    const_item_cache= FALSE;
+  }
+}
+
+bool Item_func_sp::check_vcol_func_processor(void *arg)
+{
+  return mark_unsupported_function(func_name(), "()", arg, VCOL_IMPOSSIBLE);
+}
+
+/*
+  uuid_short handling.
+
+  The short uuid is defined as a longlong that contains the following bytes:
+
+  Bytes  Comment
+  1      Server_id & 255
+  4      Startup time of server in seconds
+  3      Incrementor
+
+  This means that an uuid is guaranteed to be unique
+  even in a replication environment if the following holds:
+
+  - The last byte of the server id is unique
+  - If you between two shutdown of the server don't get more than
+    an average of 2^24 = 16M calls to uuid_short() per second.
+*/
+
+ulonglong uuid_value;
+
+void uuid_short_init()
+{
+  uuid_value= ((((ulonglong) global_system_variables.server_id) << 56) +
+               (((ulonglong) server_start_time) << 24));
+}
+
+ulonglong server_uuid_value()
+{
+  ulonglong val;
+  mysql_mutex_lock(&LOCK_short_uuid_generator);
+  val= uuid_value++;
+  mysql_mutex_unlock(&LOCK_short_uuid_generator);
+  return val;
+}
+
+longlong Item_func_uuid_short::val_int()
+{
+  return (longlong) server_uuid_value();
+}
+
+
+/**
+  Last_value - return last argument.
+*/
+
+void Item_func_last_value::evaluate_sideeffects()
+{
+  DBUG_ASSERT(fixed() && arg_count > 0);
+  for (uint i= 0; i < arg_count-1 ; i++)
+    args[i]->val_int();
+}
+
+String *Item_func_last_value::val_str(String *str)
+{
+  String *tmp;
+  evaluate_sideeffects();
+  tmp= last_value->val_str(str);
+  null_value= last_value->null_value;
+  return tmp;
+}
+
+
+bool Item_func_last_value::val_native(THD *thd, Native *to)
+{
+  evaluate_sideeffects();
+  return val_native_from_item(thd, last_value, to);
+}
+
+
+longlong Item_func_last_value::val_int()
+{
+  longlong tmp;
+  evaluate_sideeffects();
+  tmp= last_value->val_int();
+  null_value= last_value->null_value;
+  return tmp;
+}
+
+double Item_func_last_value::val_real()
+{
+  double tmp;
+  evaluate_sideeffects();
+  tmp= last_value->val_real();
+  null_value= last_value->null_value;
+  return tmp;
+}
+
+my_decimal *Item_func_last_value::val_decimal(my_decimal *decimal_value)
+{
+  my_decimal *tmp;
+  evaluate_sideeffects();
+  tmp= last_value->val_decimal(decimal_value);
+  null_value= last_value->null_value;
+  return tmp;
+}
+
+
+bool Item_func_last_value::get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate)
+{
+  evaluate_sideeffects();
+  bool tmp= last_value->get_date(thd, ltime, fuzzydate);
+  null_value= last_value->null_value;
+  return tmp;
+}
+
+
+bool Item_func_last_value::fix_length_and_dec(THD *thd)
+{
+  last_value=          args[arg_count -1];
+  Type_std_attributes::set(last_value);
+  set_maybe_null(last_value->maybe_null());
+  return FALSE;
+}
+
+
+void Cursor_ref::print_func(String *str, const LEX_CSTRING &func_name)
+{
+  append_identifier(current_thd, str, &m_cursor_name);
+  str->append(func_name);
+}
+
+
+sp_cursor *Cursor_ref::get_open_cursor_or_error()
+{
+  THD *thd= current_thd;
+  sp_cursor *c= thd->spcont->get_cursor(m_cursor_offset);
+  DBUG_ASSERT(c);
+  if (!c/*safety*/ || !c->is_open())
+  {
+    my_message(ER_SP_CURSOR_NOT_OPEN, ER_THD(thd, ER_SP_CURSOR_NOT_OPEN),
+               MYF(0));
+    return NULL;
+  }
+  return c;
+}
+
+
+longlong Item_func_cursor_isopen::val_int()
+{
+  sp_cursor *c= current_thd->spcont->get_cursor(m_cursor_offset);
+  DBUG_ASSERT(c != NULL);
+  return c ? c->is_open() : 0;
+}
+
+
+longlong Item_func_cursor_found::val_int()
+{
+  sp_cursor *c= get_open_cursor_or_error();
+  return !(null_value= (!c || c->fetch_count() == 0)) && c->found();
+}
+
+
+longlong Item_func_cursor_notfound::val_int()
+{
+  sp_cursor *c= get_open_cursor_or_error();
+  return !(null_value= (!c || c->fetch_count() == 0)) && !c->found();
+}
+
+
+longlong Item_func_cursor_rowcount::val_int()
+{
+  sp_cursor *c= get_open_cursor_or_error();
+  return !(null_value= !c) ? c->row_count() : 0;
+}
+
+/*****************************************************************************
+  SEQUENCE functions
+*****************************************************************************/
+
+longlong Item_func_nextval::val_int()
+{
+  longlong value;
+  int error;
+  const char *key;
+  uint length= get_table_def_key(table_list, &key);
+  THD *thd;
+  SEQUENCE_LAST_VALUE *entry;
+  char buff[80];
+  String key_buff(buff,sizeof(buff), &my_charset_bin);
+  DBUG_ENTER("Item_func_nextval::val_int");
+  update_table();
+  DBUG_ASSERT(table && table->s->sequence);
+  thd= table->in_use;
+
+  if (thd->count_cuted_fields == CHECK_FIELD_EXPRESSION)
+  {
+    /* Alter table checking if function works */
+    null_value= 0;
+    DBUG_RETURN(0);
+  }
+
+  if (table->s->tmp_table != NO_TMP_TABLE)
+  {
+    /*
+      Temporary tables has an extra \0 at end to distinguish it from
+      normal tables
+    */
+    key_buff.copy(key, length, &my_charset_bin);
+    key_buff.append((char) 0);
+    key= key_buff.ptr();
+    length++;
+  }
+
+  if (!(entry= ((SEQUENCE_LAST_VALUE*)
+                my_hash_search(&thd->sequences, (uchar*) key, length))))
+  {
+    if (!(key= (char*) my_memdup(PSI_INSTRUMENT_ME, key, length, MYF(MY_WME))) ||
+        !(entry= new SEQUENCE_LAST_VALUE((uchar*) key, length)))
+    {
+      /* EOM, error given */
+      my_free((char*) key);
+      delete entry;
+      null_value= 1;
+      DBUG_RETURN(0);
+    }
+    if (my_hash_insert(&thd->sequences, (uchar*) entry))
+    {
+      /* EOM, error given */
+      delete entry;
+      null_value= 1;
+      DBUG_RETURN(0);
+    }
+  }
+  entry->null_value= null_value= 0;
+  value= table->s->sequence->next_value(table, 0, &error);
+  entry->value= value;
+  entry->set_version(table);
+
+  if (unlikely(error))                          // Warning already printed
+    entry->null_value= null_value= 1;           // For not strict mode
+  DBUG_RETURN(value);
+}
+
+
+/* Print for nextval and lastval */
+
+void Item_func_nextval::print(String *str, enum_query_type query_type)
+{
+  char d_name_buff[MAX_ALIAS_NAME], t_name_buff[MAX_ALIAS_NAME];
+  LEX_CSTRING d_name= table_list->db;
+  LEX_CSTRING t_name= table_list->table_name;
+  bool use_db_name= d_name.str && d_name.str[0];
+  THD *thd= current_thd;                        // Don't trust 'table'
+
+  str->append(func_name_cstring());
+  str->append('(');
+
+  /*
+    for next_val we assume that table_list has been updated to contain
+    the current db.
+  */
+
+  if (lower_case_table_names > 0)
+  {
+    strmake(t_name_buff, t_name.str, MAX_ALIAS_NAME-1);
+    t_name.length= my_casedn_str(files_charset_info, t_name_buff);
+    t_name.str= t_name_buff;
+    if (use_db_name)
+    {
+      strmake(d_name_buff, d_name.str, MAX_ALIAS_NAME-1);
+      d_name.length= my_casedn_str(files_charset_info, d_name_buff);
+      d_name.str= d_name_buff;
+    }
+  }
+
+  if (use_db_name)
+  {
+    append_identifier(thd, str, &d_name);
+    str->append('.');
+  }
+  append_identifier(thd, str, &t_name);
+  str->append(')');
+}
+
+
+/* Return last used value for sequence or NULL if sequence hasn't been used */
+
+longlong Item_func_lastval::val_int()
+{
+  const char *key;
+  SEQUENCE_LAST_VALUE *entry;
+  uint length= get_table_def_key(table_list, &key);
+  THD *thd;
+  char buff[80];
+  String key_buff(buff,sizeof(buff), &my_charset_bin);
+  DBUG_ENTER("Item_func_lastval::val_int");
+  update_table();
+  thd= table->in_use;
+
+  if (table->s->tmp_table != NO_TMP_TABLE)
+  {
+    /*
+      Temporary tables has an extra \0 at end to distinguish it from
+      normal tables
+    */
+    key_buff.copy(key, length, &my_charset_bin);
+    key_buff.append((char) 0);
+    key= key_buff.ptr();
+    length++;
+  }
+
+  if (!(entry= ((SEQUENCE_LAST_VALUE*)
+                my_hash_search(&thd->sequences, (uchar*) key, length))))
+  {
+    /* Sequence not used */
+    null_value= 1;
+    DBUG_RETURN(0);
+  }
+  if (entry->check_version(table))
+  {
+    /* Table droped and re-created, remove current version */
+    my_hash_delete(&thd->sequences, (uchar*) entry);
+    null_value= 1;
+    DBUG_RETURN(0);
+  }    
+
+  null_value= entry->null_value;
+  DBUG_RETURN(entry->value);
+}
+
+
+/*
+  Sets next value to be returned from sequences
+
+  SELECT setval(foo, 42, 0);           Next nextval will return 43
+  SELECT setval(foo, 42, 0, true);     Same as above
+  SELECT setval(foo, 42, 0, false);    Next nextval will return 42
+*/
+
+longlong Item_func_setval::val_int()
+{
+  longlong value;
+  int error;
+  THD *thd;
+  DBUG_ENTER("Item_func_setval::val_int");
+
+  update_table();
+  DBUG_ASSERT(table && table->s->sequence);
+  thd= table->in_use;
+
+  if (unlikely(thd->count_cuted_fields == CHECK_FIELD_EXPRESSION))
+  {
+    /* Alter table checking if function works */
+    null_value= 0;
+    DBUG_RETURN(0);
+  }
+
+  value= nextval;
+  error= table->s->sequence->set_value(table, nextval, round, is_used);
+  if (unlikely(error))
+  {
+    null_value= 1;
+    value= 0;
+  }
+  DBUG_RETURN(value);
+}
+
+
+/* Print for setval */
+
+void Item_func_setval::print(String *str, enum_query_type query_type)
+{
+  char d_name_buff[MAX_ALIAS_NAME], t_name_buff[MAX_ALIAS_NAME];
+  LEX_CSTRING d_name= table_list->db;
+  LEX_CSTRING t_name= table_list->table_name;
+  bool use_db_name= d_name.str && d_name.str[0];
+  THD *thd= current_thd;                        // Don't trust 'table'
+
+  str->append(func_name_cstring());
+  str->append('(');
+
+  /*
+    for next_val we assume that table_list has been updated to contain
+    the current db.
+  */
+
+  if (lower_case_table_names > 0)
+  {
+    strmake(t_name_buff, t_name.str, MAX_ALIAS_NAME-1);
+    t_name.length= my_casedn_str(files_charset_info, t_name_buff);
+    t_name.str= t_name_buff;
+    if (use_db_name)
+    {
+      strmake(d_name_buff, d_name.str, MAX_ALIAS_NAME-1);
+      d_name.length= my_casedn_str(files_charset_info, d_name_buff);
+      d_name.str= d_name_buff;
+    }
+  }
+
+  if (use_db_name)
+  {
+    append_identifier(thd, str, &d_name);
+    str->append('.');
+  }
+  append_identifier(thd, str, &t_name);
+  str->append(',');
+  str->append_longlong(nextval);
+  str->append(',');
+  str->append_longlong(is_used);
+  str->append(',');
+  str->append_ulonglong(round);
+  str->append(')');
+}
+
+
+/*
+  Return how many row combinations has accepted so far + 1
+
+  The + 1 is to ensure that, for example, 'WHERE ROWNUM <=1' returns one row
+*/
+
+longlong Item_func_rownum::val_int()
+{
+  if (!accepted_rows)
+  {
+    /*
+      Rownum is not properly set up. Probably used in wrong context when
+      it should not be used. In this case returning 0 is probably the best
+      solution.
+    */
+    return 0;
+  }
+  return (longlong) *accepted_rows+1;
+}
+
+
+Item_func_rownum::Item_func_rownum(THD *thd):
+  Item_longlong_func(thd),accepted_rows(0)
+{
+  /*
+    Remember the select context.
+    Add the function to the list fix_after_optimize in the select context
+    so that we can easily initializef all rownum functions with the pointers
+    to the row counters.
+  */
+  select= thd->lex->current_select;
+  select->fix_after_optimize.push_back(this, thd->mem_root);
+
+  /*
+    Mark that query is using rownum() and ensure that this select is
+    not merged with other selects
+  */
+  select->with_rownum= 1;
+  thd->lex->with_rownum= 1;
+  thd->lex->uncacheable(UNCACHEABLE_RAND);
+  with_flags= with_flags | item_with_t::ROWNUM_FUNC;
+
+  /* If this command changes data, mark it as unsafe for statement logging */
+  if (sql_command_flags[thd->lex->sql_command] &
+      (CF_UPDATES_DATA | CF_DELETES_DATA))
+    thd->lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_SYSTEM_FUNCTION);
+}
+
+
+/*
+  Store a reference to the variable that contains number of accepted rows
+*/
+
+void Item_func_rownum::fix_after_optimize(THD *thd)
+{
+  accepted_rows= &select->join->accepted_rows;
+}
+
+/*
+  Inform all ROWNUM() function where the number of rows are stored
+*/
+
+void fix_rownum_pointers(THD *thd, SELECT_LEX *select_lex, ha_rows *ptr)
+{
+  List_iterator<Item> li(select_lex->fix_after_optimize);
+  while (Item *item= li++)
+  {
+    if (item->type() == Item::FUNC_ITEM &&
+        ((Item_func*) item)->functype() == Item_func::ROWNUM_FUNC)
+      ((Item_func_rownum*) item)->store_pointer_to_row_counter(ptr);
+  }
+}