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

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

1 files changed, 1553 insertions, 0 deletions

diff --git a/sql/set_var.cc b/sql/set_var.cc
new file mode 100644
index 00000000..aa9ec5ab
--- /dev/null
+++ b/sql/set_var.cc
@@ -0,0 +1,1553 @@
+/* Copyright (c) 2002, 2013, Oracle and/or its affiliates.
+   Copyright (c) 2008, 2014, SkySQL Ab.
+
+   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 */
+
+/* variable declarations are in sys_vars.cc now !!! */
+
+#include "sql_plugin.h"
+#include "sql_class.h"                   // set_var.h: session_var_ptr
+#include "set_var.h"
+#include "sql_priv.h"
+#include "unireg.h"
+#include "mysqld.h"                             // lc_messages_dir
+#include "sys_vars_shared.h"
+#include "transaction.h"
+#include "sql_locale.h"                         // my_locale_by_number,
+                                                // my_locale_by_name
+#include "strfunc.h"      // find_set_from_flags, find_set
+#include "sql_parse.h"    // check_global_access
+#include "sql_table.h"  // reassign_keycache_tables
+#include "sql_time.h"   // date_time_format_copy,
+                        // date_time_format_make
+#include "derror.h"
+#include "tztime.h"     // my_tz_find, my_tz_SYSTEM, struct Time_zone
+#include "sql_select.h" // free_underlaid_joins
+#include "sql_i_s.h"
+#include "sql_view.h"   // updatable_views_with_limit_typelib
+#include "lock.h"                               // lock_global_read_lock,
+                                                // make_global_read_lock_block_commit,
+                                                // unlock_global_read_lock
+
+static HASH system_variable_hash;
+static PolyLock_mutex PLock_global_system_variables(&LOCK_global_system_variables);
+static ulonglong system_variable_hash_version= 0;
+
+/**
+  Return variable name and length for hashing of variables.
+*/
+
+static uchar *get_sys_var_length(const sys_var *var, size_t *length,
+                                 my_bool first)
+{
+  *length= var->name.length;
+  return (uchar*) var->name.str;
+}
+
+sys_var_chain all_sys_vars = { NULL, NULL };
+
+int sys_var_init()
+{
+  DBUG_ENTER("sys_var_init");
+
+  /* Must be already initialized. */
+  DBUG_ASSERT(system_charset_info != NULL);
+
+  if (my_hash_init(PSI_INSTRUMENT_ME, &system_variable_hash, system_charset_info, 700, 0,
+                   0, (my_hash_get_key) get_sys_var_length, 0, HASH_UNIQUE))
+    goto error;
+
+  if (mysql_add_sys_var_chain(all_sys_vars.first))
+    goto error;
+
+  DBUG_RETURN(0);
+
+error:
+  fprintf(stderr, "failed to initialize System variables");
+  DBUG_RETURN(1);
+}
+
+uint sys_var_elements()
+{
+  return system_variable_hash.records;
+}
+
+int sys_var_add_options(DYNAMIC_ARRAY *long_options, int parse_flags)
+{
+  size_t saved_elements= long_options->elements;
+
+  DBUG_ENTER("sys_var_add_options");
+
+  for (sys_var *var=all_sys_vars.first; var; var= var->next)
+  {
+    if (var->register_option(long_options, parse_flags))
+      goto error;
+  }
+
+  DBUG_RETURN(0);
+
+error:
+  fprintf(stderr, "failed to initialize System variables");
+  long_options->elements= saved_elements;
+  DBUG_RETURN(1);
+}
+
+void sys_var_end()
+{
+  DBUG_ENTER("sys_var_end");
+
+  my_hash_free(&system_variable_hash);
+
+  for (sys_var *var=all_sys_vars.first; var; var= var->next)
+    var->cleanup();
+
+  DBUG_VOID_RETURN;
+}
+
+
+static bool static_test_load= TRUE;
+
+/**
+  sys_var constructor
+
+  @param chain     variables are linked into chain for mysql_add_sys_var_chain()
+  @param name_arg  the name of the variable. Must be 0-terminated and exist
+                   for the liftime of the sys_var object. @sa my_option::name
+  @param comment   shown in mysqld --help, @sa my_option::comment
+  @param flags_arg or'ed flag_enum values
+  @param off       offset of the global variable value from the
+                   &global_system_variables.
+  @param getopt_id -1 for no command-line option, otherwise @sa my_option::id
+  @param getopt_arg_type @sa my_option::arg_type
+  @param show_val_type_arg what value_ptr() returns for sql_show.cc
+  @param def_val   default value, @sa my_option::def_value
+  @param lock      mutex or rw_lock that protects the global variable
+                   *in addition* to LOCK_global_system_variables.
+  @param binlog_status_enum @sa binlog_status_enum
+  @param on_check_func a function to be called at the end of sys_var::check,
+                   put your additional checks here
+  @param on_update_func a function to be called at the end of sys_var::update,
+                   any post-update activity should happen here
+  @param substitute If non-NULL, this variable is deprecated and the
+  string describes what one should use instead. If an empty string,
+  the variable is deprecated but no replacement is offered.
+*/
+sys_var::sys_var(sys_var_chain *chain, const char *name_arg,
+                 const char *comment, int flags_arg, ptrdiff_t off,
+                 int getopt_id, enum get_opt_arg_type getopt_arg_type,
+                 SHOW_TYPE show_val_type_arg, longlong def_val,
+                 PolyLock *lock, enum binlog_status_enum binlog_status_arg,
+                 on_check_function on_check_func,
+                 on_update_function on_update_func,
+                 const char *substitute) :
+  next(0), binlog_status(binlog_status_arg), value_origin(COMPILE_TIME),
+  flags(flags_arg), show_val_type(show_val_type_arg),
+  guard(lock), offset(off), on_check(on_check_func), on_update(on_update_func),
+  deprecation_substitute(substitute)
+{
+  /*
+    There is a limitation in handle_options() related to short options:
+    - either all short options should be declared when parsing in multiple stages,
+    - or none should be declared.
+    Because a lot of short options are used in the normal parsing phase
+    for mysqld, we enforce here that no short option is present
+    in the first (PARSE_EARLY) stage.
+    See handle_options() for details.
+  */
+  DBUG_ASSERT(!(flags & PARSE_EARLY) || getopt_id <= 0 || getopt_id >= 255);
+
+  name.str= name_arg;     // ER_NO_DEFAULT relies on 0-termination of name_arg
+  name.length= strlen(name_arg);                // and so does this.
+  DBUG_ASSERT(name.length <= NAME_CHAR_LEN);
+
+  bzero(&option, sizeof(option));
+  option.name= name_arg;
+  option.id= getopt_id;
+  option.comment= comment;
+  option.arg_type= getopt_arg_type;
+  option.value= (uchar **)global_var_ptr();
+  option.def_value= def_val;
+  option.app_type= this;
+  option.var_type= flags & AUTO_SET ? GET_AUTO : 0;
+
+  if (chain->last)
+    chain->last->next= this;
+  else
+    chain->first= this;
+  chain->last= this;
+
+  test_load= &static_test_load;
+}
+
+bool sys_var::update(THD *thd, set_var *var)
+{
+  enum_var_type type= var->type;
+  if (type == OPT_GLOBAL || scope() == GLOBAL)
+  {
+    /*
+      Yes, both locks need to be taken before an update, just as
+      both are taken to get a value. If we'll take only 'guard' here,
+      then value_ptr() for strings won't be safe in SHOW VARIABLES anymore,
+      to make it safe we'll need value_ptr_unlock().
+    */
+    AutoWLock lock1(&PLock_global_system_variables);
+    AutoWLock lock2(guard);
+    value_origin= SQL;
+    return global_update(thd, var) ||
+      (on_update && on_update(this, thd, OPT_GLOBAL));
+  }
+  else
+  {
+    bool ret= session_update(thd, var) ||
+      (on_update && on_update(this, thd, OPT_SESSION));
+
+    /*
+      Make sure we don't session-track variables that are not actually
+      part of the session. tx_isolation and and tx_read_only for example
+      exist as GLOBAL, SESSION, and one-shot ("for next transaction only").
+    */
+    if ((var->type == OPT_SESSION) && (!ret))
+    {
+      thd->session_tracker.sysvars.mark_as_changed(thd, var->var);
+      /*
+        Here MySQL sends variable name to avoid reporting change of
+        the tracker itself, but we decided that it is not needed
+      */
+      thd->session_tracker.state_change.mark_as_changed(thd);
+    }
+
+    return ret;
+  }
+}
+
+const uchar *sys_var::session_value_ptr(THD *thd, const LEX_CSTRING *base) const
+{
+  return session_var_ptr(thd);
+}
+
+const uchar *sys_var::global_value_ptr(THD *thd, const LEX_CSTRING *base) const
+{
+  return global_var_ptr();
+}
+
+bool sys_var::check(THD *thd, set_var *var)
+{
+  if (unlikely((var->value && do_check(thd, var)) ||
+               (on_check && on_check(this, thd, var))))
+  {
+    if (likely(!thd->is_error()))
+    {
+      char buff[STRING_BUFFER_USUAL_SIZE];
+      String str(buff, sizeof(buff), system_charset_info), *res;
+
+      if (!var->value)
+      {
+        str.set(STRING_WITH_LEN("DEFAULT"), &my_charset_latin1);
+        res= &str;
+      }
+      else if (!(res=var->value->val_str(&str)))
+      {
+        str.set(STRING_WITH_LEN("NULL"), &my_charset_latin1);
+        res= &str;
+      }
+      ErrConvString err(res);
+      my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), name.str, err.ptr());
+    }
+    return true;
+  }
+  return false;
+}
+
+const uchar *sys_var::value_ptr(THD *thd, enum_var_type type,
+                                const LEX_CSTRING *base) const
+{
+  DBUG_ASSERT(base);
+  if (type == OPT_GLOBAL || scope() == GLOBAL)
+  {
+    mysql_mutex_assert_owner(&LOCK_global_system_variables);
+    AutoRLock lock(guard);
+    return global_value_ptr(thd, base);
+  }
+  else
+    return session_value_ptr(thd, base);
+}
+
+bool sys_var::set_default(THD *thd, set_var* var)
+{
+  if (var->type == OPT_GLOBAL || scope() == GLOBAL)
+    global_save_default(thd, var);
+  else
+    session_save_default(thd, var);
+
+  return check(thd, var) || update(thd, var);
+}
+
+
+#define do_num_val(T,CMD)                           \
+do {                                                \
+  T val= *(T*) value;                               \
+  CMD;                                              \
+} while (0)
+
+#define case_for_integers(CMD)                      \
+    case SHOW_SINT:     do_num_val (int,CMD);       \
+    case SHOW_SLONG:    do_num_val (long,CMD);      \
+    case SHOW_SLONGLONG:do_num_val (longlong,CMD);  \
+    case SHOW_UINT:     do_num_val (uint,CMD);      \
+    case SHOW_ULONG:    do_num_val (ulong,CMD);     \
+    case SHOW_ULONGLONG:do_num_val (ulonglong,CMD); \
+    case SHOW_HA_ROWS:  do_num_val (ha_rows,CMD);
+
+#define case_for_double(CMD)                        \
+    case SHOW_DOUBLE:   do_num_val (double,CMD)
+
+#define case_get_string_as_lex_string               \
+    case SHOW_CHAR:                                 \
+      sval.str= (char*) value;                      \
+      sval.length= sval.str ? strlen(sval.str) : 0; \
+      break;                                        \
+    case SHOW_CHAR_PTR:                             \
+      sval.str= *(char**) value;                    \
+      sval.length= sval.str ? strlen(sval.str) : 0; \
+      break;                                        \
+    case SHOW_LEX_STRING:                           \
+      sval= *(LEX_CSTRING *) value;                  \
+      break
+
+longlong sys_var::val_int(bool *is_null,
+                          THD *thd, enum_var_type type,
+                          const LEX_CSTRING *base)
+{
+  LEX_CSTRING sval;
+  AutoWLock lock(&PLock_global_system_variables);
+  const uchar *value= value_ptr(thd, type, base);
+  *is_null= false;
+
+  switch (show_type())
+  {
+    case_get_string_as_lex_string;
+    case_for_integers(return val);
+    case_for_double(return (longlong) val);
+    case SHOW_MY_BOOL:  return *(my_bool*)value;
+    default:            
+      my_error(ER_VAR_CANT_BE_READ, MYF(0), name.str); 
+      return 0;
+  }
+
+  longlong ret= 0;
+  if (!(*is_null= !sval.str))
+    ret= longlong_from_string_with_check(charset(thd),
+                                         sval.str, sval.str + sval.length);
+  return ret;
+}
+
+
+String *sys_var::val_str_nolock(String *str, THD *thd, const uchar *value)
+{
+  static LEX_CSTRING bools[]=
+  {
+    { STRING_WITH_LEN("OFF") },
+    { STRING_WITH_LEN("ON") }
+  };
+
+  LEX_CSTRING sval;
+  switch (show_type())
+  {
+    case_get_string_as_lex_string;
+    case_for_integers(return str->set(val, system_charset_info) ? 0 : str);
+    case_for_double(return str->set_real(val, 6, system_charset_info) ? 0 : str);
+    case SHOW_MY_BOOL:
+      sval= bools[(int)*(my_bool*)value];
+      break;
+    default:
+      my_error(ER_VAR_CANT_BE_READ, MYF(0), name.str);
+      return 0;
+  }
+
+  if (!sval.str || str->copy(sval.str, sval.length, charset(thd)))
+    str= NULL;
+  return str;
+}
+
+
+String *sys_var::val_str(String *str,
+                         THD *thd, enum_var_type type, const LEX_CSTRING *base)
+{
+  AutoWLock lock(&PLock_global_system_variables);
+  const uchar *value= value_ptr(thd, type, base);
+  return val_str_nolock(str, thd, value);
+}
+
+
+double sys_var::val_real(bool *is_null,
+                         THD *thd, enum_var_type type, const LEX_CSTRING *base)
+{
+  LEX_CSTRING sval;
+  AutoWLock lock(&PLock_global_system_variables);
+  const uchar *value= value_ptr(thd, type, base);
+  *is_null= false;
+
+  switch (show_type())
+  {
+    case_get_string_as_lex_string;
+    case_for_integers(return (double)val);
+    case_for_double(return val);
+    case SHOW_MY_BOOL:  return *(my_bool*)value;
+    default:            
+      my_error(ER_VAR_CANT_BE_READ, MYF(0), name.str); 
+      return 0;
+  }
+
+  double ret= 0;
+  if (!(*is_null= !sval.str))
+    ret= double_from_string_with_check(charset(thd),
+                                       sval.str, sval.str + sval.length);
+  return ret;
+}
+
+
+void sys_var::do_deprecated_warning(THD *thd)
+{
+  if (deprecation_substitute != NULL)
+  {
+    char buf1[NAME_CHAR_LEN + 3];
+    strxnmov(buf1, sizeof(buf1)-1, "@@", name.str, 0);
+
+    /* 
+       if deprecation_substitute is an empty string,
+       there is no replacement for the syntax
+    */
+    uint errmsg= deprecation_substitute[0] == '\0'
+      ? ER_WARN_DEPRECATED_SYNTAX_NO_REPLACEMENT
+      : ER_WARN_DEPRECATED_SYNTAX;
+    if (thd)
+      push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
+                          ER_WARN_DEPRECATED_SYNTAX, ER_THD(thd, errmsg),
+                          buf1, deprecation_substitute);
+    else
+      sql_print_warning(ER_DEFAULT(errmsg), buf1, deprecation_substitute);
+  }
+}
+
+/**
+  Throw warning (error in STRICT mode) if value for variable needed bounding.
+  Plug-in interface also uses this.
+
+  @param thd         thread handle
+  @param name        variable's name
+  @param fixed       did we have to correct the value? (throw warn/err if so)
+  @param is_unsigned is value's type unsigned?
+  @param v           variable's value
+
+  @retval         true on error, false otherwise (warning or ok)
+ */
+
+
+bool throw_bounds_warning(THD *thd, const char *name,const char *v)
+{
+  if (thd->variables.sql_mode & MODE_STRICT_ALL_TABLES)
+  {
+    my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), name, v);
+    return true;
+  }
+  push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
+                      ER_TRUNCATED_WRONG_VALUE,
+                      ER_THD(thd, ER_TRUNCATED_WRONG_VALUE), name, v);
+  return false;
+}
+
+
+bool throw_bounds_warning(THD *thd, const char *name,
+                          bool fixed, bool is_unsigned, longlong v)
+{
+  if (fixed)
+  {
+    char buf[22];
+
+    if (is_unsigned)
+      ullstr((ulonglong) v, buf);
+    else
+      llstr(v, buf);
+
+    if (thd->variables.sql_mode & MODE_STRICT_ALL_TABLES)
+    {
+      my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), name, buf);
+      return true;
+    }
+    return throw_bounds_warning(thd, name, buf);
+  }
+  return false;
+}
+
+bool throw_bounds_warning(THD *thd, const char *name, bool fixed, double v)
+{
+  if (fixed)
+  {
+    char buf[64];
+
+    my_gcvt(v, MY_GCVT_ARG_DOUBLE, sizeof(buf) - 1, buf, NULL);
+
+    if (thd->variables.sql_mode & MODE_STRICT_ALL_TABLES)
+    {
+      my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), name, buf);
+      return true;
+    }
+    return throw_bounds_warning(thd, name, buf);
+  }
+  return false;
+}
+
+
+typedef struct old_names_map_st
+{
+  const char *old_name;
+  const char *new_name;
+} my_old_conv;
+
+static my_old_conv old_conv[]=
+{
+  {     "cp1251_koi8"           ,       "cp1251"        },
+  {     "cp1250_latin2"         ,       "cp1250"        },
+  {     "kam_latin2"            ,       "keybcs2"       },
+  {     "mac_latin2"            ,       "MacRoman"      },
+  {     "macce_latin2"          ,       "MacCE"         },
+  {     "pc2_latin2"            ,       "pclatin2"      },
+  {     "vga_latin2"            ,       "pclatin1"      },
+  {     "koi8_cp1251"           ,       "koi8r"         },
+  {     "win1251ukr_koi8_ukr"   ,       "win1251ukr"    },
+  {     "koi8_ukr_win1251ukr"   ,       "koi8u"         },
+  {     NULL                    ,       NULL            }
+};
+
+CHARSET_INFO *get_old_charset_by_name(const char *name)
+{
+  my_old_conv *conv;
+  for (conv= old_conv; conv->old_name; conv++)
+  {
+    if (!my_strcasecmp(&my_charset_latin1, name, conv->old_name))
+      return get_charset_by_csname(conv->new_name, MY_CS_PRIMARY, MYF(0));
+  }
+  return NULL;
+}
+
+/****************************************************************************
+  Main handling of variables:
+  - Initialisation
+  - Searching during parsing
+  - Update loop
+****************************************************************************/
+
+/**
+  Add variables to the dynamic hash of system variables
+
+  @param first       Pointer to first system variable to add
+
+  @retval
+    0           SUCCESS
+  @retval
+    otherwise   FAILURE
+*/
+
+
+int mysql_add_sys_var_chain(sys_var *first)
+{
+  sys_var *var;
+
+  /* A write lock should be held on LOCK_system_variables_hash */
+
+  for (var= first; var; var= var->next)
+  {
+    /* this fails if there is a conflicting variable name. see HASH_UNIQUE */
+    if (my_hash_insert(&system_variable_hash, (uchar*) var))
+    {
+      fprintf(stderr, "*** duplicate variable name '%s' ?\n", var->name.str);
+      goto error;
+    }
+  }
+  /* Update system_variable_hash version. */
+  system_variable_hash_version++;
+  return 0;
+
+error:
+  for (; first != var; first= first->next)
+    my_hash_delete(&system_variable_hash, (uchar*) first);
+  return 1;
+}
+
+
+/*
+  Remove variables to the dynamic hash of system variables
+
+  SYNOPSIS
+    mysql_del_sys_var_chain()
+    first       Pointer to first system variable to remove
+
+  RETURN VALUES
+    0           SUCCESS
+    otherwise   FAILURE
+*/
+
+int mysql_del_sys_var_chain(sys_var *first)
+{
+  int result= 0;
+
+  mysql_prlock_wrlock(&LOCK_system_variables_hash);
+  for (sys_var *var= first; var; var= var->next)
+    result|= my_hash_delete(&system_variable_hash, (uchar*) var);
+  mysql_prlock_unlock(&LOCK_system_variables_hash);
+
+  /* Update system_variable_hash version. */
+  system_variable_hash_version++;
+  return result;
+}
+
+
+static int show_cmp(SHOW_VAR *a, SHOW_VAR *b)
+{
+  return strcmp(a->name, b->name);
+}
+
+
+/*
+  Number of records in the system_variable_hash.
+  Requires lock on LOCK_system_variables_hash.
+*/
+ulong get_system_variable_hash_records(void)
+{
+  return system_variable_hash.records;
+}
+
+
+/**
+  Constructs an array of system variables for display to the user.
+
+  @param thd       current thread
+  @param sorted    If TRUE, the system variables should be sorted
+  @param scope     OPT_GLOBAL or OPT_SESSION for SHOW GLOBAL|SESSION VARIABLES
+
+  @retval
+    pointer     Array of SHOW_VAR elements for display
+  @retval
+    NULL        FAILURE
+*/
+
+SHOW_VAR* enumerate_sys_vars(THD *thd, bool sorted, enum enum_var_type scope)
+{
+  int count= system_variable_hash.records, i;
+  int size= sizeof(SHOW_VAR) * (count + 1);
+  SHOW_VAR *result= (SHOW_VAR*) thd->alloc(size);
+
+  if (result)
+  {
+    SHOW_VAR *show= result;
+
+    for (i= 0; i < count; i++)
+    {
+      sys_var *var= (sys_var*) my_hash_element(&system_variable_hash, i);
+
+      // don't show session-only variables in SHOW GLOBAL VARIABLES
+      if (scope == OPT_GLOBAL && var->check_type(scope))
+        continue;
+
+      show->name= var->name.str;
+      show->value= (char*) var;
+      show->type= SHOW_SYS;
+      show++;
+    }
+
+    /* sort into order */
+    if (sorted)
+      my_qsort(result, show-result, sizeof(SHOW_VAR),
+               (qsort_cmp) show_cmp);
+
+    /* make last element empty */
+    bzero(show, sizeof(SHOW_VAR));
+  }
+  return result;
+}
+
+/**
+  Find a user set-table variable.
+
+  @param str       Name of system variable to find
+  @param length    Length of variable.  zero means that we should use strlen()
+                   on the variable
+
+  @retval
+    pointer     pointer to variable definitions
+  @retval
+    0           Unknown variable (error message is given)
+*/
+
+sys_var *intern_find_sys_var(const char *str, size_t length)
+{
+  sys_var *var;
+
+  /*
+    This function is only called from the sql_plugin.cc.
+    A lock on LOCK_system_variable_hash should be held
+  */
+  var= (sys_var*) my_hash_search(&system_variable_hash,
+                              (uchar*) str, length ? length : strlen(str));
+
+  return var;
+}
+
+
+/**
+  Execute update of all variables.
+
+  First run a check of all variables that all updates will go ok.
+  If yes, then execute all updates, returning an error if any one failed.
+
+  This should ensure that in all normal cases none all or variables are
+  updated.
+
+  @param THD            Thread id
+  @param var_list       List of variables to update
+
+  @retval
+    0   ok
+  @retval
+    1   ERROR, message sent (normally no variables was updated)
+  @retval
+    -1  ERROR, message not sent
+*/
+
+int sql_set_variables(THD *thd, List<set_var_base> *var_list, bool free)
+{
+  int error= 0;
+  bool was_error= thd->is_error();
+  List_iterator_fast<set_var_base> it(*var_list);
+  DBUG_ENTER("sql_set_variables");
+
+  set_var_base *var;
+  while ((var=it++))
+  {
+    if (unlikely((error= var->check(thd))))
+      goto err;
+  }
+  if (unlikely(was_error) || likely(!(error= MY_TEST(thd->is_error()))))
+  {
+    it.rewind();
+    while ((var= it++))
+      error|= var->update(thd);         // Returns 0, -1 or 1
+  }
+
+err:
+  if (free)
+    free_underlaid_joins(thd, thd->lex->first_select_lex());
+  DBUG_RETURN(error);
+}
+
+/*****************************************************************************
+  Functions to handle SET mysql_internal_variable=const_expr
+*****************************************************************************/
+
+bool sys_var::on_check_access_global(THD *thd) const
+{
+  return check_global_access(thd, PRIV_SET_GLOBAL_SYSTEM_VARIABLE);
+}
+
+/**
+  Verify that the supplied value is correct.
+
+  @param thd Thread handler
+
+  @return status code
+   @retval -1 Failure
+   @retval 0 Success
+ */
+
+int set_var::check(THD *thd)
+{
+  var->do_deprecated_warning(thd);
+  if (var->is_readonly())
+  {
+    my_error(ER_INCORRECT_GLOBAL_LOCAL_VAR, MYF(0), var->name.str, "read only");
+    return -1;
+  }
+  if (var->check_type(type))
+  {
+    int err= type == OPT_GLOBAL ? ER_LOCAL_VARIABLE : ER_GLOBAL_VARIABLE;
+    my_error(err, MYF(0), var->name.str);
+    return -1;
+  }
+  if (type == OPT_GLOBAL && var->on_check_access_global(thd))
+    return 1;
+  /* value is a NULL pointer if we are using SET ... = DEFAULT */
+  if (!value)
+    return 0;
+
+  if (value->fix_fields_if_needed_for_scalar(thd, &value))
+    return -1;
+  if (var->check_update_type(value))
+  {
+    my_error(ER_WRONG_TYPE_FOR_VAR, MYF(0), var->name.str);
+    return -1;
+  }
+  switch (type) {
+  case SHOW_OPT_DEFAULT:
+  case SHOW_OPT_SESSION:
+    DBUG_ASSERT(var->scope() != sys_var::GLOBAL);
+    if (var->on_check_access_session(thd))
+      return -1;
+    break;
+  case SHOW_OPT_GLOBAL:  // Checked earlier
+    break;
+  }
+  return var->check(thd, this) ? -1 : 0;
+}
+
+
+/**
+  Check variable, but without assigning value (used by PS).
+
+  @param thd            thread handler
+
+  @retval
+    0   ok
+  @retval
+    1   ERROR, message sent (normally no variables was updated)
+  @retval
+    -1   ERROR, message not sent
+*/
+int set_var::light_check(THD *thd)
+{
+  if (var->is_readonly())
+  {
+    my_error(ER_INCORRECT_GLOBAL_LOCAL_VAR, MYF(0), var->name.str, "read only");
+    return -1;
+  }
+  if (var->check_type(type))
+  {
+    int err= type == OPT_GLOBAL ? ER_LOCAL_VARIABLE : ER_GLOBAL_VARIABLE;
+    my_error(err, MYF(0), var->name.str);
+    return -1;
+  }
+
+  if (type == OPT_GLOBAL && var->on_check_access_global(thd))
+      return 1;
+
+  if (value && value->fix_fields_if_needed_for_scalar(thd, &value))
+    return -1;
+  return 0;
+}
+
+/**
+  Update variable
+
+  @param   thd    thread handler
+  @returns 0|1    ok or ERROR
+
+  @note ERROR can be only due to abnormal operations involving
+  the server's execution evironment such as
+  out of memory, hard disk failure or the computer blows up.
+  Consider set_var::check() method if there is a need to return
+  an error due to logics.
+*/
+
+int set_var::update(THD *thd)
+{
+  return value ? var->update(thd, this) : var->set_default(thd, this);
+}
+
+
+set_var::set_var(THD *thd, enum_var_type type_arg, sys_var *var_arg,
+                 const LEX_CSTRING *base_name_arg, Item *value_arg)
+  :var(var_arg), type(type_arg), base(*base_name_arg)
+{
+  /*
+    If the set value is a field, change it to a string to allow things like
+    SET table_type=MYISAM;
+  */
+  if (value_arg && value_arg->type() == Item::FIELD_ITEM)
+  {
+    Item_field *item= (Item_field*) value_arg;
+    // names are utf8
+    if (!(value= new (thd->mem_root) Item_string_sys(thd,
+                                                     item->field_name.str,
+                                                     (uint)item->field_name.length)))
+      value=value_arg;                        /* Give error message later */
+  }
+  else
+    value=value_arg;
+}
+
+
+/*****************************************************************************
+  Functions to handle SET @user_variable=const_expr
+*****************************************************************************/
+
+int set_var_user::check(THD *thd)
+{
+  /*
+    Item_func_set_user_var can't substitute something else on its place =>
+    0 can be passed as last argument (reference on item)
+  */
+  return (user_var_item->fix_fields(thd, (Item**) 0) ||
+          user_var_item->check(0)) ? -1 : 0;
+}
+
+
+/**
+  Check variable, but without assigning value (used by PS).
+
+  @param thd            thread handler
+
+  @retval
+    0   ok
+  @retval
+    1   ERROR, message sent (normally no variables was updated)
+  @retval
+    -1   ERROR, message not sent
+*/
+int set_var_user::light_check(THD *thd)
+{
+  /*
+    Item_func_set_user_var can't substitute something else on its place =>
+    0 can be passed as last argument (reference on item)
+  */
+  return (user_var_item->fix_fields(thd, (Item**) 0));
+}
+
+
+int set_var_user::update(THD *thd)
+{
+  if (user_var_item->update())
+  {
+    /* Give an error if it's not given already */
+    my_message(ER_SET_CONSTANTS_ONLY, ER_THD(thd, ER_SET_CONSTANTS_ONLY),
+               MYF(0));
+    return -1;
+  }
+
+  thd->session_tracker.state_change.mark_as_changed(thd);
+  return 0;
+}
+
+
+/*****************************************************************************
+  Functions to handle SET PASSWORD
+*****************************************************************************/
+
+int set_var_password::check(THD *thd)
+{
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+  return check_change_password(thd, user);
+#else
+  return 0;
+#endif
+}
+
+int set_var_password::update(THD *thd)
+{
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+  Reprepare_observer *save_reprepare_observer= thd->m_reprepare_observer;
+  thd->m_reprepare_observer= 0;
+  int res= change_password(thd, user);
+  thd->m_reprepare_observer= save_reprepare_observer;
+  return res;
+#else
+  return 0;
+#endif
+}
+
+/*****************************************************************************
+  Functions to handle SET ROLE
+*****************************************************************************/
+
+int set_var_role::check(THD *thd)
+{
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+  int status= acl_check_setrole(thd, role.str, &access);
+  return status;
+#else
+  return 0;
+#endif
+}
+
+int set_var_role::update(THD *thd)
+{
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+  int res= acl_setrole(thd, role.str, access);
+  if (!res)
+    thd->session_tracker.state_change.mark_as_changed(thd);
+  return res;
+#else
+  return 0;
+#endif
+}
+
+/*****************************************************************************
+  Functions to handle SET DEFAULT ROLE
+*****************************************************************************/
+
+int set_var_default_role::check(THD *thd)
+{
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+  real_user= get_current_user(thd, user);
+  real_role= role.str;
+  if (role.str == current_role.str)
+  {
+    if (!thd->security_ctx->priv_role[0])
+      real_role= "NONE";
+    else
+      real_role= thd->security_ctx->priv_role;
+  }
+
+  return acl_check_set_default_role(thd, real_user->host.str,
+                                    real_user->user.str, real_role);
+#else
+  return 0;
+#endif
+}
+
+int set_var_default_role::update(THD *thd)
+{
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+  Reprepare_observer *save_reprepare_observer= thd->m_reprepare_observer;
+  thd->m_reprepare_observer= 0;
+  int res= acl_set_default_role(thd, real_user->host.str, real_user->user.str,
+                                real_role);
+  thd->m_reprepare_observer= save_reprepare_observer;
+  return res;
+#else
+  return 0;
+#endif
+}
+
+/*****************************************************************************
+  Functions to handle SET NAMES and SET CHARACTER SET
+*****************************************************************************/
+
+int set_var_collation_client::check(THD *thd)
+{
+  /* Currently, UCS-2 cannot be used as a client character set */
+  if (!is_supported_parser_charset(character_set_client))
+  {
+    my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), "character_set_client",
+             character_set_client->cs_name.str);
+    return 1;
+  }
+  return 0;
+}
+
+int set_var_collation_client::update(THD *thd)
+{
+  thd->update_charset(character_set_client, collation_connection,
+                      character_set_results);
+
+  /* Mark client collation variables as changed */
+  thd->session_tracker.sysvars.mark_as_changed(thd,
+                                               Sys_character_set_client_ptr);
+  thd->session_tracker.sysvars.mark_as_changed(thd,
+                                               Sys_character_set_results_ptr);
+  thd->session_tracker.sysvars.mark_as_changed(thd,
+                                               Sys_character_set_connection_ptr);
+  thd->session_tracker.state_change.mark_as_changed(thd);
+
+  thd->protocol_text.init(thd);
+  thd->protocol_binary.init(thd);
+  return 0;
+}
+
+/*****************************************************************************
+ INFORMATION_SCHEMA.SYSTEM_VARIABLES
+*****************************************************************************/
+static void store_value_ptr(Field *field, sys_var *var, String *str,
+                            const uchar *value_ptr)
+{
+  field->set_notnull();
+  str= var->val_str_nolock(str, field->table->in_use, value_ptr);
+  if (str)
+    field->store(str->ptr(), str->length(), str->charset());
+}
+
+static void store_var(Field *field, sys_var *var, enum_var_type scope,
+                      String *str)
+{
+  if (var->check_type(scope))
+    return;
+
+  store_value_ptr(field, var, str,
+                  var->value_ptr(field->table->in_use, scope, &null_clex_str));
+}
+
+int fill_sysvars(THD *thd, TABLE_LIST *tables, COND *cond)
+{
+  char name_buffer[NAME_CHAR_LEN];
+  bool res= 1;
+  CHARSET_INFO *scs= system_charset_info;
+  StringBuffer<STRING_BUFFER_USUAL_SIZE> strbuf(scs);
+  const char *wild= thd->lex->wild ? thd->lex->wild->ptr() : 0;
+  Field **fields=tables->table->field;
+  bool has_file_acl= !check_access(thd, FILE_ACL, any_db.str, NULL,NULL,0,1);
+
+  DBUG_ASSERT(tables->table->in_use == thd);
+
+  cond= make_cond_for_info_schema(thd, cond, tables);
+  mysql_prlock_rdlock(&LOCK_system_variables_hash);
+
+  for (uint i= 0; i < system_variable_hash.records; i++)
+  {
+    sys_var *var= (sys_var*) my_hash_element(&system_variable_hash, i);
+
+    strmake_buf(name_buffer, var->name.str);
+    my_caseup_str(system_charset_info, name_buffer);
+
+    /* this must be done before evaluating cond */
+    restore_record(tables->table, s->default_values);
+    fields[0]->store(name_buffer, strlen(name_buffer), scs);
+
+    if ((wild && wild_case_compare(system_charset_info, name_buffer, wild))
+        || (cond && !cond->val_int()))
+      continue;
+
+    mysql_mutex_lock(&LOCK_global_system_variables);
+
+    // SESSION_VALUE
+    store_var(fields[1], var, OPT_SESSION, &strbuf);
+
+    // GLOBAL_VALUE
+    store_var(fields[2], var, OPT_GLOBAL, &strbuf);
+
+    // GLOBAL_VALUE_ORIGIN
+    static const LEX_CSTRING origins[]=
+    {
+      { STRING_WITH_LEN("CONFIG") },
+      { STRING_WITH_LEN("COMMAND-LINE") },
+      { STRING_WITH_LEN("AUTO") },
+      { STRING_WITH_LEN("SQL") },
+      { STRING_WITH_LEN("COMPILE-TIME") },
+      { STRING_WITH_LEN("ENVIRONMENT") }
+    };
+    const LEX_CSTRING *origin= origins + var->value_origin;
+    fields[3]->store(origin->str, origin->length, scs);
+
+    // DEFAULT_VALUE
+    const uchar *def= var->is_readonly() && var->option.id < 0
+                      ? 0 : var->default_value_ptr(thd);
+    if (def)
+      store_value_ptr(fields[4], var, &strbuf, def);
+
+    mysql_mutex_unlock(&LOCK_global_system_variables);
+
+    // VARIABLE_SCOPE
+    static const LEX_CSTRING scopes[]=
+    {
+      { STRING_WITH_LEN("GLOBAL") },
+      { STRING_WITH_LEN("SESSION") },
+      { STRING_WITH_LEN("SESSION ONLY") }
+    };
+    const LEX_CSTRING *scope= scopes + var->scope();
+    fields[5]->store(scope->str, scope->length, scs);
+
+    // VARIABLE_TYPE
+#if SIZEOF_LONG == SIZEOF_INT
+#define LONG_TYPE "INT"
+#else
+#define LONG_TYPE "BIGINT"
+#endif
+
+    static const LEX_CSTRING types[]=
+    {
+      { 0, 0 },                                      // unused         0
+      { 0, 0 },                                      // GET_NO_ARG     1
+      { STRING_WITH_LEN("BOOLEAN") },                // GET_BOOL       2
+      { STRING_WITH_LEN("INT") },                    // GET_INT        3
+      { STRING_WITH_LEN("INT UNSIGNED") },           // GET_UINT       4
+      { STRING_WITH_LEN(LONG_TYPE) },                // GET_LONG       5
+      { STRING_WITH_LEN(LONG_TYPE " UNSIGNED") },    // GET_ULONG      6
+      { STRING_WITH_LEN("BIGINT") },                 // GET_LL         7
+      { STRING_WITH_LEN("BIGINT UNSIGNED") },        // GET_ULL        8
+      { STRING_WITH_LEN("VARCHAR") },                // GET_STR        9
+      { STRING_WITH_LEN("VARCHAR") },                // GET_STR_ALLOC 10
+      { 0, 0 },                                      // GET_DISABLED  11
+      { STRING_WITH_LEN("ENUM") },                   // GET_ENUM      12
+      { STRING_WITH_LEN("SET") },                    // GET_SET       13
+      { STRING_WITH_LEN("DOUBLE") },                 // GET_DOUBLE    14
+      { STRING_WITH_LEN("FLAGSET") },                // GET_FLAGSET   15
+      { STRING_WITH_LEN("BOOLEAN") },                // GET_BIT       16
+    };
+    const ulong vartype= (var->option.var_type & GET_TYPE_MASK);
+    const LEX_CSTRING *type= types + vartype;
+    fields[6]->store(type->str, type->length, scs);
+
+    // VARIABLE_COMMENT
+    fields[7]->store(var->option.comment, strlen(var->option.comment),
+                           scs);
+
+    // NUMERIC_MIN_VALUE
+    // NUMERIC_MAX_VALUE
+    // NUMERIC_BLOCK_SIZE
+    bool is_unsigned= true;
+    switch (vartype)
+    {
+    case GET_INT:
+    case GET_LONG:
+    case GET_LL:
+      is_unsigned= false;
+      /* fall through */
+    case GET_UINT:
+    case GET_ULONG:
+    case GET_ULL:
+      fields[8]->set_notnull();
+      fields[9]->set_notnull();
+      fields[10]->set_notnull();
+      fields[8]->store(var->option.min_value, is_unsigned);
+      fields[9]->store(var->option.max_value, is_unsigned);
+      fields[10]->store(var->option.block_size, is_unsigned);
+      break;
+    case GET_DOUBLE:
+      fields[8]->set_notnull();
+      fields[9]->set_notnull();
+      fields[8]->store(getopt_ulonglong2double(var->option.min_value));
+      fields[9]->store(getopt_ulonglong2double(var->option.max_value));
+    }
+
+    // ENUM_VALUE_LIST
+    TYPELIB *tl= var->option.typelib;
+    if (tl)
+    {
+      uint i;
+      strbuf.length(0);
+      for (i=0; i < tl->count; i++)
+      {
+        const char *name= tl->type_names[i];
+        strbuf.append(name, strlen(name));
+        strbuf.append(',');
+      }
+      if (!strbuf.is_empty())
+        strbuf.chop();
+      fields[11]->set_notnull();
+      fields[11]->store(strbuf.ptr(), strbuf.length(), scs);
+    }
+
+    // READ_ONLY
+    static const LEX_CSTRING yesno[]=
+    {
+      { STRING_WITH_LEN("NO") },
+      { STRING_WITH_LEN("YES") }
+    };
+    const LEX_CSTRING *yn = yesno + var->is_readonly();
+    fields[12]->store(yn->str, yn->length, scs);
+
+    // COMMAND_LINE_ARGUMENT
+    if (var->option.id >= 0)
+    {
+      static const LEX_CSTRING args[]=
+      {
+        { STRING_WITH_LEN("NONE") },          // NO_ARG
+        { STRING_WITH_LEN("OPTIONAL") },      // OPT_ARG
+        { STRING_WITH_LEN("REQUIRED") }       // REQUIRED_ARG
+      };
+      const LEX_CSTRING *arg= args + var->option.arg_type;
+      fields[13]->set_notnull();
+      fields[13]->store(arg->str, arg->length, scs);
+    }
+
+    // GLOBAL_VALUE_PATH
+    if (var->value_origin == sys_var::CONFIG && has_file_acl)
+    {
+      fields[14]->set_notnull();
+      fields[14]->store(var->origin_filename, strlen(var->origin_filename),
+                        files_charset_info);
+    }
+
+    if (schema_table_store_record(thd, tables->table))
+      goto end;
+    thd->get_stmt_da()->inc_current_row_for_warning();
+  }
+  res= 0;
+end:
+  mysql_prlock_unlock(&LOCK_system_variables_hash);
+  return res;
+}
+
+/*
+  This is a simple and inefficient helper that sets sys_var::value_origin
+  for a specific sysvar.
+  It should *only* be used on server startup, if you need to do this later,
+  get yourself a pointer to your sysvar (see e.g. Sys_autocommit_ptr)
+  and update it directly.
+*/
+
+void set_sys_var_value_origin(void *ptr, enum sys_var::where here,
+                              const char *filename)
+{
+  bool found __attribute__((unused))= false;
+  DBUG_ASSERT(!mysqld_server_started); // only to be used during startup
+
+  for (uint i= 0; i < system_variable_hash.records; i++)
+  {
+    sys_var *var= (sys_var*) my_hash_element(&system_variable_hash, i);
+    if (var->option.value == ptr)
+    {
+      found= true;
+      var->origin_filename= filename;
+      var->value_origin= here;
+      /* don't break early, search for all matches */
+    }
+  }
+
+  DBUG_ASSERT(found); // variable must have been found
+}
+
+enum sys_var::where get_sys_var_value_origin(void *ptr)
+{
+  DBUG_ASSERT(!mysqld_server_started); // only to be used during startup
+
+  for (uint i= 0; i < system_variable_hash.records; i++)
+  {
+    sys_var *var= (sys_var*) my_hash_element(&system_variable_hash, i);
+    if (var->option.value == ptr)
+    {
+      return var->value_origin; //first match
+    }
+  }
+
+  DBUG_ASSERT(0); // variable must have been found
+  return sys_var::CONFIG;
+}
+
+
+/*
+  Find the next item in string of comma-separated items.
+  END_POS points at the end of the string.
+  ITEM_START and ITEM_END return the limits of the next item.
+  Returns true while items are available, false at the end.
+*/
+static bool
+engine_list_next_item(const char **pos, const char *end_pos,
+                      const char **item_start, const char **item_end)
+{
+  if (*pos >= end_pos)
+    return false;
+  *item_start= *pos;
+  while (*pos < end_pos && **pos != ',')
+    ++*pos;
+  *item_end= *pos;
+  ++*pos;
+  return true;
+}
+
+
+static bool
+resolve_engine_list_item(THD *thd, plugin_ref *list, uint32 *idx,
+                         const char *pos, const char *pos_end,
+                         bool error_on_unknown_engine, bool temp_copy)
+{
+  LEX_CSTRING item_str;
+  plugin_ref ref;
+  uint32 i;
+  THD *thd_or_null = (temp_copy ? thd : NULL);
+
+  item_str.str= pos;
+  item_str.length= pos_end-pos;
+  ref= ha_resolve_by_name(thd_or_null, &item_str, false);
+  if (!ref)
+  {
+    if (error_on_unknown_engine)
+    {
+      ErrConvString err(pos, pos_end-pos, system_charset_info);
+      my_error(ER_UNKNOWN_STORAGE_ENGINE, MYF(0), err.ptr());
+      return true;
+    }
+    return false;
+  }
+  /* Ignore duplicates, like --plugin-load does. */
+  for (i= 0; i < *idx; ++i)
+  {
+    if (plugin_hton(list[i]) == plugin_hton(ref))
+    {
+      if (!temp_copy)
+        plugin_unlock(NULL, ref);
+      return false;
+    }
+  }
+  list[*idx]= ref;
+  ++*idx;
+  return false;
+}
+
+
+/*
+  Helper for class Sys_var_pluginlist.
+  Resolve a comma-separated list of storage engine names to a null-terminated
+  array of plugin_ref.
+
+  If TEMP_COPY is true, a THD must be given as well. In this case, the
+  allocated memory and locked plugins are registered in the THD and will
+  be freed / unlocked automatically. If TEMP_COPY is true, THD can be
+  passed as NULL, and resources must be freed explicitly later with
+  free_engine_list().
+*/
+plugin_ref *
+resolve_engine_list(THD *thd, const char *str_arg, size_t str_arg_len,
+                    bool error_on_unknown_engine, bool temp_copy)
+{
+  uint32 count, idx;
+  const char *pos, *item_start, *item_end;
+  const char *str_arg_end= str_arg + str_arg_len;
+  plugin_ref *res;
+
+  count= 0;
+  pos= str_arg;
+  for (;;)
+  {
+    if (!engine_list_next_item(&pos, str_arg_end, &item_start, &item_end))
+      break;
+    ++count;
+  }
+
+  if (temp_copy)
+    res= (plugin_ref *)thd->calloc((count+1)*sizeof(*res));
+  else
+    res= (plugin_ref *)my_malloc(PSI_INSTRUMENT_ME, (count+1)*sizeof(*res), MYF(MY_ZEROFILL|MY_WME));
+  if (!res)
+  {
+    my_error(ER_OUTOFMEMORY, MYF(0), (int)((count+1)*sizeof(*res)));
+    goto err;
+  }
+
+  idx= 0;
+  pos= str_arg;
+  for (;;)
+  {
+    if (!engine_list_next_item(&pos, str_arg_end, &item_start, &item_end))
+      break;
+    DBUG_ASSERT(idx < count);
+    if (idx >= count)
+      break;
+    if (resolve_engine_list_item(thd, res, &idx, item_start, item_end,
+                                 error_on_unknown_engine, temp_copy))
+      goto err;
+  }
+
+  return res;
+
+err:
+  if (!temp_copy)
+    free_engine_list(res);
+  return NULL;
+}
+
+
+void
+free_engine_list(plugin_ref *list)
+{
+  plugin_ref *p;
+
+  if (!list)
+    return;
+  for (p= list; *p; ++p)
+    plugin_unlock(NULL, *p);
+  my_free(list);
+}
+
+
+plugin_ref *
+copy_engine_list(plugin_ref *list)
+{
+  plugin_ref *p;
+  uint32 count, i;
+
+  for (p= list, count= 0; *p; ++p, ++count)
+    ;
+  p= (plugin_ref *)my_malloc(PSI_INSTRUMENT_ME, (count+1)*sizeof(*p), MYF(0));
+  if (!p)
+  {
+    my_error(ER_OUTOFMEMORY, MYF(0), (int)((count+1)*sizeof(*p)));
+    return NULL;
+  }
+  for (i= 0; i < count; ++i)
+    p[i]= my_plugin_lock(NULL, list[i]);
+  p[i] = NULL;
+  return p;
+}
+
+
+/*
+  Create a temporary copy of an engine list. The memory will be freed
+  (and the plugins unlocked) automatically, on the passed THD.
+*/
+plugin_ref *
+temp_copy_engine_list(THD *thd, plugin_ref *list)
+{
+  plugin_ref *p;
+  uint32 count, i;
+
+  for (p= list, count= 0; *p; ++p, ++count)
+    ;
+  p= (plugin_ref *)thd->alloc((count+1)*sizeof(*p));
+  if (!p)
+  {
+    my_error(ER_OUTOFMEMORY, MYF(0), (int)((count+1)*sizeof(*p)));
+    return NULL;
+  }
+  for (i= 0; i < count; ++i)
+    p[i]= my_plugin_lock(thd, list[i]);
+  p[i] = NULL;
+  return p;
+}
+
+
+char *
+pretty_print_engine_list(THD *thd, plugin_ref *list)
+{
+  plugin_ref *p;
+  size_t size;
+  char *buf, *pos;
+
+  if (!list || !*list)
+    return thd->strmake("", 0);
+
+  size= 0;
+  for (p= list; *p; ++p)
+    size+= plugin_name(*p)->length + 1;
+  buf= static_cast<char *>(thd->alloc(size));
+  if (!buf)
+    return NULL;
+  pos= buf;
+  for (p= list; *p; ++p)
+  {
+    LEX_CSTRING *name;
+    size_t remain;
+
+    remain= buf + size - pos;
+    DBUG_ASSERT(remain > 0);
+    if (remain <= 1)
+      break;
+    if (pos != buf)
+    {
+      pos= strmake(pos, ",", remain-1);
+      --remain;
+    }
+    name= plugin_name(*p);
+    pos= strmake(pos, name->str, MY_MIN(name->length, remain-1));
+  }
+  *pos= '\0';
+  return buf;
+}
+
+/*
+  Current version of the system_variable_hash.
+  Requires lock on LOCK_system_variables_hash.
+*/
+ulonglong get_system_variable_hash_version(void)
+{
+  return system_variable_hash_version;
+}
+