Lots of small cleanups

- Simplified use_trans_cache() to return at once if is_transactional is set
- Indentation and spelling errors fixed
- Don't call signal_update() if update_binlog_end_pos() is called as the
  function already calls signal_update()
- Removed not used function wait_for_update_bin_log(), which would cause
  errors if ever used.
- Simplified handler::clone() by always allocating 'ref' in ha_open(). To do
  this I added an optional MEM_ROOT argument to ha_open() to be used when
  allocating 'ref'
- Changed arguments to get_system_var() from LEX_CSTRING to LEX_CSTRING*
- Added THD as argument to create_select_for_variable(). Changed also char*
  argument to LEX_CSTRING to avoid strlen() call.
- Change calls to append() to use LEX_CSTRING

33 files changed, 147 insertions, 144 deletions

diff --git a/extra/mariabackup/ds_archive.c b/extra/mariabackup/ds_archive.c
index 50afcce4bc7..ae473bc3385 100644
--- a/extra/mariabackup/ds_archive.c
+++ b/extra/mariabackup/ds_archive.c
@@ -18,6 +18,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 
 *******************************************************/
 
+#include <my_global.h>
 #include <my_base.h>
 #include <archive.h>
 #include <archive_entry.h>
diff --git a/extra/mariabackup/encryption_plugin.cc b/extra/mariabackup/encryption_plugin.cc
index 208a6b8e419..b88c149673b 100644
--- a/extra/mariabackup/encryption_plugin.cc
+++ b/extra/mariabackup/encryption_plugin.cc
@@ -1,3 +1,18 @@
+/* Copyright (c) 2017, MariaDB Corporation.
+
+   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 Street, Fifth Floor, Boston, MA  02110-1301, USA */
+
 #include <my_global.h>
 #include <mysqld.h>
 #include <mysql.h>
diff --git a/extra/mariabackup/fil_cur.cc b/extra/mariabackup/fil_cur.cc
index e00827076d6..fa6cad57016 100644
--- a/extra/mariabackup/fil_cur.cc
+++ b/extra/mariabackup/fil_cur.cc
@@ -24,7 +24,6 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 
 #include <my_global.h>
 #include <my_base.h>
-
 #include <fil0fil.h>
 #include <fsp0fsp.h>
 #include <srv0start.h>
diff --git a/extra/mariabackup/xtrabackup.cc b/extra/mariabackup/xtrabackup.cc
index 83c40a14bbd..4904d7b7b35 100644
--- a/extra/mariabackup/xtrabackup.cc
+++ b/extra/mariabackup/xtrabackup.cc
@@ -43,6 +43,7 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 
 //#define XTRABACKUP_TARGET_IS_PLUGIN
 
+#include <my_global.h>
 #include <my_config.h>
 #include <unireg.h>
 #include <mysql_version.h>
diff --git a/mysys/thr_mutex.c b/mysys/thr_mutex.c
index 9256af4aa98..49cb3ea600f 100644
--- a/mysys/thr_mutex.c
+++ b/mysys/thr_mutex.c
@@ -149,10 +149,11 @@ static inline void remove_from_active_list(safe_mutex_t *mp)
 }
 
 /*
-  We initialise the hashes for deadlock detection lazily.
-  This greatly helps with performance when lots of mutexes are initiased but
+  We initialize the hashes for deadlock detection lazily.
+  This greatly helps with performance when lots of mutexes are initialized but
   only a few of them are actually used (eg. InnoDB).
 */
+
 static int safe_mutex_lazy_init_deadlock_detection(safe_mutex_t *mp)
 {
   if (!my_multi_malloc(MY_FAE | MY_WME,
diff --git a/sql/event_data_objects.cc b/sql/event_data_objects.cc
index 631e3388084..02ac5633d65 100644
--- a/sql/event_data_objects.cc
+++ b/sql/event_data_objects.cc
@@ -1236,7 +1236,7 @@ Event_timed::get_create_event(THD *thd, String *buf)
     append_unescaped(buf, comment.str, comment.length);
   }
   buf->append(STRING_WITH_LEN(" DO "));
-  buf->append(body.str, body.length);
+  buf->append(&body);
 
   DBUG_RETURN(0);
 }
@@ -1284,7 +1284,7 @@ Event_job_data::construct_sp_sql(THD *thd, String *sp_sql)
   */
   sp_sql->append(C_STRING_WITH_LEN("() SQL SECURITY INVOKER "));
 
-  sp_sql->append(body.str, body.length);
+  sp_sql->append(&body);
 
   DBUG_RETURN(thd->is_fatal_error);
 }
diff --git a/sql/event_scheduler.cc b/sql/event_scheduler.cc
index a38425a7c4e..e8b586801d6 100644
--- a/sql/event_scheduler.cc
+++ b/sql/event_scheduler.cc
@@ -85,7 +85,7 @@ Event_worker_thread::print_warnings(THD *thd, Event_job_data *et)
   char prefix_buf[5 * STRING_BUFFER_USUAL_SIZE];
   String prefix(prefix_buf, sizeof(prefix_buf), system_charset_info);
   prefix.length(0);
-  prefix.append("Event Scheduler: [");
+  prefix.append(STRING_WITH_LEN("Event Scheduler: ["));
 
   prefix.append(et->definer.str, et->definer.length, system_charset_info);
   prefix.append("][", 2);
diff --git a/sql/handler.cc b/sql/handler.cc
index adff97c395b..926551fdd60 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -2360,6 +2360,18 @@ int ha_delete_table(THD *thd, handlerton *table_type, const char *path,
 /****************************************************************************
 ** General handler functions
 ****************************************************************************/
+
+
+/**
+   Clone a handler
+
+   @param name     name of new table instance
+   @param mem_root Where 'this->ref' should be allocated. It can't be
+                   in this->table->mem_root as otherwise we will not be
+                   able to reclaim that memory when the clone handler
+                   object is destroyed.
+*/
+
 handler *handler::clone(const char *name, MEM_ROOT *mem_root)
 {
   handler *new_handler= get_new_handler(table->s, mem_root, ht);
@@ -2370,16 +2382,6 @@ handler *handler::clone(const char *name, MEM_ROOT *mem_root)
     goto err;
 
   /*
-    Allocate handler->ref here because otherwise ha_open will allocate it
-    on this->table->mem_root and we will not be able to reclaim that memory 
-    when the clone handler object is destroyed.
-  */
-
-  if (!(new_handler->ref= (uchar*) alloc_root(mem_root,
-                                              ALIGN_SIZE(ref_length)*2)))
-    goto err;
-
-  /*
     TODO: Implement a more efficient way to have more than one index open for
     the same table instance. The ha_open call is not cachable for clone.
 
@@ -2387,7 +2389,7 @@ handler *handler::clone(const char *name, MEM_ROOT *mem_root)
     and should be able to use the original instance of the table.
   */
   if (new_handler->ha_open(table, name, table->db_stat,
-                           HA_OPEN_IGNORE_IF_LOCKED))
+                           HA_OPEN_IGNORE_IF_LOCKED, mem_root))
     goto err;
 
   return new_handler;
@@ -2465,7 +2467,7 @@ PSI_table_share *handler::ha_table_share_psi() const
     Don't wait for locks if not HA_OPEN_WAIT_IF_LOCKED is set
 */
 int handler::ha_open(TABLE *table_arg, const char *name, int mode,
-                     uint test_if_locked)
+                     uint test_if_locked, MEM_ROOT *mem_root)
 {
   int error;
   DBUG_ENTER("handler::ha_open");
@@ -2512,9 +2514,9 @@ int handler::ha_open(TABLE *table_arg, const char *name, int mode,
       table->db_stat|=HA_READ_ONLY;
     (void) extra(HA_EXTRA_NO_READCHECK);	// Not needed in SQL
 
-    /* ref is already allocated for us if we're called from handler::clone() */
-    if (!ref && !(ref= (uchar*) alloc_root(&table->mem_root, 
-                                          ALIGN_SIZE(ref_length)*2)))
+    /* Allocate ref in thd or on the table's mem_root */
+    if (!(ref= (uchar*) alloc_root(mem_root ? mem_root : &table->mem_root, 
+                                   ALIGN_SIZE(ref_length)*2)))
     {
       ha_close();
       error=HA_ERR_OUT_OF_MEM;
diff --git a/sql/handler.h b/sql/handler.h
index 75205dda957..86287596ca3 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -2832,7 +2832,8 @@ public:
   }
   /* ha_ methods: pubilc wrappers for private virtual API */
   
-  int ha_open(TABLE *table, const char *name, int mode, uint test_if_locked);
+  int ha_open(TABLE *table, const char *name, int mode, uint test_if_locked,
+              MEM_ROOT *mem_root= 0);
   int ha_index_init(uint idx, bool sorted)
   {
     DBUG_EXECUTE_IF("ha_index_init_fail", return HA_ERR_TABLE_DEF_CHANGED;);
diff --git a/sql/item.cc b/sql/item.cc
index d67301e8d04..fe20687bf51 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -1691,7 +1691,7 @@ Item_splocal::this_item_addr(THD *thd, Item **)
 void Item_splocal::print(String *str, enum_query_type)
 {
   str->reserve(m_name.length+8);
-  str->append(m_name.str, m_name.length);
+  str->append(&m_name);
   str->append('@');
   str->qs_append(m_var_idx);
 }
@@ -1816,9 +1816,9 @@ Item_splocal_row_field::this_item_addr(THD *thd, Item **)
 void Item_splocal_row_field::print(String *str, enum_query_type)
 {
   str->reserve(m_name.length + m_field_name.length + 8);
-  str->append(m_name.str, m_name.length);
+  str->append(&m_name);
   str->append('.');
-  str->append(m_field_name.str, m_field_name.length);
+  str->append(&m_field_name);
   str->append('@');
   str->qs_append(m_var_idx);
   str->append('[');
@@ -1854,13 +1854,13 @@ void Item_splocal_row_field_by_name::print(String *str, enum_query_type)
   // +16 should be enough for .NNN@[""]
   if (str->reserve(m_name.length + 2 * m_field_name.length + 16))
     return;
-  str->qs_append(m_name.str, m_name.length);
+  str->qs_append(&m_name);
   str->qs_append('.');
-  str->qs_append(m_field_name.str, m_field_name.length);
+  str->qs_append(&m_field_name);
   str->qs_append('@');
   str->qs_append(m_var_idx);
   str->qs_append("[\"", 2);
-  str->qs_append(m_field_name.str, m_field_name.length);
+  str->qs_append(&m_field_name);
   str->qs_append("\"]", 2);
 }
 
diff --git a/sql/item_func.cc b/sql/item_func.cc
index 4a91f9a4938..7d00e868bae 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -4995,7 +4995,7 @@ bool Item_func_set_user_var::is_null_result()
 void Item_func_set_user_var::print(String *str, enum_query_type query_type)
 {
   str->append(STRING_WITH_LEN("@"));
-  str->append(name.str, name.length);
+  str->append(&name);
   str->append(STRING_WITH_LEN(":="));
   args[0]->print_parenthesised(str, query_type, precedence());
 }
@@ -5005,7 +5005,7 @@ 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, name.length);
+  str->append(&name);
   str->append(STRING_WITH_LEN(":="));
   args[0]->print_parenthesised(str, query_type, precedence());
 }
@@ -5588,7 +5588,7 @@ void Item_func_get_system_var::fix_length_and_dec()
 void Item_func_get_system_var::print(String *str, enum_query_type query_type)
 {
   if (name.length)
-    str->append(name.str, name.length);
+    str->append(&name);
   else
   {
     str->append(STRING_WITH_LEN("@@"));
@@ -6122,39 +6122,41 @@ longlong Item_func_bit_xor::val_int()
 */
 
 
-Item *get_system_var(THD *thd, enum_var_type var_type, LEX_CSTRING name,
-		     LEX_CSTRING component)
+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;
+  LEX_CSTRING base_name, component_name;
 
-  if (component.str)
+  if (component->str)
   {
-    base_name= &component;
-    component_name= &name;
+    base_name= *component;
+    component_name= *name;
   }
   else
   {
-    base_name= &name;
-    component_name= &component;			// Empty string
+    base_name= *name;
+    component_name= *component;			// Empty string
   }
 
-  if (!(var= find_sys_var(thd, base_name->str, base_name->length)))
+  if (!(var= find_sys_var(thd, base_name.str, base_name.length)))
     return 0;
-  if (component.str)
+  if (component->str)
   {
     if (!var->is_struct())
     {
-      my_error(ER_VARIABLE_IS_NOT_STRUCT, MYF(0), base_name->str);
+      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);
+  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);
+  return new (thd->mem_root) Item_func_get_system_var(thd, var, var_type,
+                                                      &component_name,
+                                                      NULL, 0);
 }
 
 
diff --git a/sql/item_func.h b/sql/item_func.h
index 9a6254438f0..a25d9aed4d7 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -2975,8 +2975,8 @@ public:
 };
 
 
-Item *get_system_var(THD *thd, enum_var_type var_type, LEX_CSTRING name,
-                     LEX_CSTRING component);
+Item *get_system_var(THD *thd, enum_var_type var_type,
+                     const LEX_CSTRING *name, const LEX_CSTRING *component);
 extern bool check_reserved_words(const LEX_CSTRING *name);
 Item *find_date_time_item(Item **args, uint nargs, uint col);
 double my_double_round(double value, longlong dec, bool dec_unsigned,
diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc
index b184ba86ea4..cdcb5ed9421 100644
--- a/sql/item_subselect.cc
+++ b/sql/item_subselect.cc
@@ -949,7 +949,7 @@ void Item_subselect::print(String *str, enum_query_type query_type)
 {
   if (query_type & QT_ITEM_SUBSELECT_ID_ONLY)
   {
-    str->append("(subquery#");
+    str->append(STRING_WITH_LEN("(subquery#"));
     if (unit && unit->first_select())
     {
       char buf[64];
@@ -4358,7 +4358,6 @@ void subselect_union_engine::print(String *str, enum_query_type query_type)
 void subselect_uniquesubquery_engine::print(String *str,
                                             enum_query_type query_type)
 {
-  const char *table_name= tab->table->s->table_name.str;
   str->append(STRING_WITH_LEN("<primary_index_lookup>("));
   tab->ref.items[0]->print(str, query_type);
   str->append(STRING_WITH_LEN(" in "));
@@ -4371,7 +4370,7 @@ void subselect_uniquesubquery_engine::print(String *str,
     str->append(STRING_WITH_LEN("<temporary table>"));
   }
   else
-    str->append(table_name, tab->table->s->table_name.length);
+    str->append(&tab->table->s->table_name);
   KEY *key_info= tab->table->key_info+ tab->ref.key;
   str->append(STRING_WITH_LEN(" on "));
   str->append(key_info->name);
@@ -4395,7 +4394,7 @@ void subselect_uniquesubquery_engine::print(String *str)
   for (uint i= 0; i < key_info->user_defined_key_parts; i++)
     tab->ref.items[i]->print(str);
   str->append(STRING_WITH_LEN(" in "));
-  str->append(tab->table->s->table_name.str, tab->table->s->table_name.length);
+  str->append(&tab->table->s->table_name);
   str->append(STRING_WITH_LEN(" on "));
   str->append(key_info->name);
   if (cond)
diff --git a/sql/log.cc b/sql/log.cc
index 20ab472d04a..deba614d096 100644
--- a/sql/log.cc
+++ b/sql/log.cc
@@ -2887,27 +2887,27 @@ bool MYSQL_QUERY_LOG::write(time_t event_time, const char *user_host,
     DBUG_EXECUTE_IF("reset_log_last_time", last_time= 0;);
 
     /* Note that my_b_write() assumes it knows the length for this */
-      if (event_time != last_time)
-      {
-        last_time= event_time;
+    if (event_time != last_time)
+    {
+      last_time= event_time;
 
-        localtime_r(&event_time, &start);
+      localtime_r(&event_time, &start);
 
-        time_buff_len= my_snprintf(local_time_buff, MAX_TIME_SIZE,
-                                   "%02d%02d%02d %2d:%02d:%02d\t",
-                                   start.tm_year % 100, start.tm_mon + 1,
-                                   start.tm_mday, start.tm_hour,
-                                   start.tm_min, start.tm_sec);
+      time_buff_len= my_snprintf(local_time_buff, MAX_TIME_SIZE,
+                                 "%02d%02d%02d %2d:%02d:%02d\t",
+                                 start.tm_year % 100, start.tm_mon + 1,
+                                 start.tm_mday, start.tm_hour,
+                                 start.tm_min, start.tm_sec);
 
-        if (my_b_write(&log_file, (uchar*) local_time_buff, time_buff_len))
-          goto err;
-      }
-      else
-        if (my_b_write(&log_file, (uchar*) "\t\t" ,2) < 0)
-          goto err;
+      if (my_b_write(&log_file, (uchar*) local_time_buff, time_buff_len))
+        goto err;
+    }
+    else
+      if (my_b_write(&log_file, (uchar*) "\t\t" ,2) < 0)
+        goto err;
 
-      /* command_type, thread_id */
-      size_t length= my_snprintf(buff, 32, "%6llu ", thread_id_arg);
+    /* command_type, thread_id */
+    size_t length= my_snprintf(buff, 32, "%6llu ", thread_id_arg);
 
     if (my_b_write(&log_file, (uchar*) buff, length))
       goto err;
@@ -5433,13 +5433,14 @@ stmt_has_updated_trans_table(const THD *thd)
 */
 bool use_trans_cache(const THD* thd, bool is_transactional)
 {
+  if (is_transactional)
+    return 1;
   binlog_cache_mngr *const cache_mngr=
     (binlog_cache_mngr*) thd_get_ha_data(thd, binlog_hton);
 
-  return
-    ((thd->is_current_stmt_binlog_format_row() ||
-     thd->variables.binlog_direct_non_trans_update) ? is_transactional :
-     (is_transactional || !cache_mngr->trx_cache.empty()));
+  return ((thd->is_current_stmt_binlog_format_row() ||
+           thd->variables.binlog_direct_non_trans_update) ? 0 :
+          !cache_mngr->trx_cache.empty());
 }
 
 /**
@@ -6360,7 +6361,6 @@ err:
              */
             update_binlog_end_pos(offset);
 
-            signal_update();
             if ((error= rotate(false, &check_purge)))
               check_purge= false;
           }
@@ -7675,7 +7675,6 @@ MYSQL_BIN_LOG::trx_group_commit_leader(group_commit_entry *leader)
     else
     {
       bool any_error= false;
-      bool all_error= true;
 
       mysql_mutex_assert_not_owner(&LOCK_prepare_ordered);
       mysql_mutex_assert_owner(&LOCK_log);
@@ -7697,8 +7696,6 @@ MYSQL_BIN_LOG::trx_group_commit_leader(group_commit_entry *leader)
           current->error_cache= NULL;
           any_error= true;
         }
-        else
-          all_error= false;
         first= false;
       }
 
@@ -7712,8 +7709,6 @@ MYSQL_BIN_LOG::trx_group_commit_leader(group_commit_entry *leader)
 
       if (any_error)
         sql_print_error("Failed to run 'after_flush' hooks");
-      if (!all_error)
-        signal_update();
     }
 
     /*
@@ -8117,23 +8112,6 @@ void MYSQL_BIN_LOG::wait_for_update_relay_log(THD* thd)
     LOCK_log is released by the caller.
 */
 
-int MYSQL_BIN_LOG::wait_for_update_bin_log(THD* thd,
-                                           const struct timespec *timeout)
-{
-  int ret= 0;
-  DBUG_ENTER("wait_for_update_bin_log");
-
-  thd_wait_begin(thd, THD_WAIT_BINLOG);
-  mysql_mutex_assert_owner(&LOCK_log);
-  if (!timeout)
-    mysql_cond_wait(&update_cond, &LOCK_log);
-  else
-    ret= mysql_cond_timedwait(&update_cond, &LOCK_log,
-                              const_cast<struct timespec *>(timeout));
-  thd_wait_end(thd);
-  DBUG_RETURN(ret);
-}
-
 int MYSQL_BIN_LOG::wait_for_update_binlog_end_pos(THD* thd,
                                                   struct timespec *timeout)
 {
diff --git a/sql/log.h b/sql/log.h
index f57693f9d2a..30829bdb33c 100644
--- a/sql/log.h
+++ b/sql/log.h
@@ -711,7 +711,6 @@ public:
   void wait_for_sufficient_commits();
   void binlog_trigger_immediate_group_commit();
   void wait_for_update_relay_log(THD* thd);
-  int  wait_for_update_bin_log(THD* thd, const struct timespec * timeout);
   void init(ulong max_size);
   void init_pthread_objects();
   void cleanup();
diff --git a/sql/log_event.cc b/sql/log_event.cc
index 2f02d1db2c8..b9d802f7927 100644
--- a/sql/log_event.cc
+++ b/sql/log_event.cc
@@ -319,7 +319,7 @@ public:
       LEX_STRING tmp_str;
       if (copy_event_cache_to_string_and_reinit(m_cache, &tmp_str))
         exit(1);
-      m_ev->output_buf.append(tmp_str.str, tmp_str.length);
+      m_ev->output_buf.append(&tmp_str);
       my_free(tmp_str.str);
     }
 #else /* MySQL_SERVER */
diff --git a/sql/session_tracker.cc b/sql/session_tracker.cc
index 61680fb17f6..8d64fb29332 100644
--- a/sql/session_tracker.cc
+++ b/sql/session_tracker.cc
@@ -1216,7 +1216,7 @@ bool Transaction_state_tracker::store(THD *thd, String *buf)
           tx_isolation_typelib as it hyphenates its items.
         */
         buf->append(STRING_WITH_LEN("SET TRANSACTION ISOLATION LEVEL "));
-        buf->append(isol[tx_isol_level - 1].str, isol[tx_isol_level - 1].length);
+        buf->append(&isol[tx_isol_level - 1]);
         buf->append(STRING_WITH_LEN("; "));
       }
 
diff --git a/sql/sp_head.cc b/sql/sp_head.cc
index 11f4a0dcfde..a199a181be2 100644
--- a/sql/sp_head.cc
+++ b/sql/sp_head.cc
@@ -3357,7 +3357,7 @@ sp_instr_set::print(String *str)
   str->qs_append(STRING_WITH_LEN("set "));
   if (var)
   {
-    str->qs_append(var->name.str, var->name.length);
+    str->qs_append(&var->name);
     str->qs_append('@');
   }
   str->qs_append(m_offset);
@@ -3403,9 +3403,9 @@ sp_instr_set_row_field::print(String *str)
   if (str->reserve(rsrv))
     return;
   str->qs_append(STRING_WITH_LEN("set "));
-    str->qs_append(var->name.str, var->name.length);
+  str->qs_append(&var->name);
   str->qs_append('.');
-  str->qs_append(def->field_name.str, def->field_name.length);
+  str->qs_append(&def->field_name);
   str->qs_append('@');
   str->qs_append(m_offset);
   str->qs_append('[');
@@ -3461,13 +3461,13 @@ sp_instr_set_row_field_by_name::print(String *str)
   if (str->reserve(rsrv))
     return;
   str->qs_append(STRING_WITH_LEN("set "));
-    str->qs_append(var->name.str, var->name.length);
+  str->qs_append(&var->name);
   str->qs_append('.');
-  str->qs_append(m_field_name.str, m_field_name.length);
+  str->qs_append(&m_field_name);
   str->qs_append('@');
   str->qs_append(m_offset);
   str->qs_append("[\"",2);
-  str->qs_append(m_field_name.str, m_field_name.length);
+  str->qs_append(&m_field_name);
   str->qs_append("\"]",2);
   str->qs_append(' ');
   m_value->print(str, enum_query_type(QT_ORDINARY |
@@ -4120,7 +4120,7 @@ sp_instr_cfetch::print(String *str)
     if (str->reserve(pv->name.length+SP_INSTR_UINT_MAXLEN+2))
       return;
     str->qs_append(' ');
-    str->qs_append(pv->name.str, pv->name.length);
+    str->qs_append(&pv->name);
     str->qs_append('@');
     str->qs_append(pv->offset);
   }
diff --git a/sql/sql_acl.cc b/sql/sql_acl.cc
index faadcb3dcf1..15c55ccaef0 100644
--- a/sql/sql_acl.cc
+++ b/sql/sql_acl.cc
@@ -8381,18 +8381,18 @@ static void add_user_parameters(String *result, ACL_USER* acl_user,
     {
       DBUG_ASSERT(acl_user->salt_len);
       result->append(STRING_WITH_LEN(" IDENTIFIED BY PASSWORD '"));
-      result->append(acl_user->auth_string.str, acl_user->auth_string.length);
+      result->append(&acl_user->auth_string);
       result->append('\'');
     }
   }
   else
   {
     result->append(STRING_WITH_LEN(" IDENTIFIED VIA "));
-    result->append(acl_user->plugin.str, acl_user->plugin.length);
+    result->append(&acl_user->plugin);
     if (acl_user->auth_string.length)
     {
       result->append(STRING_WITH_LEN(" USING '"));
-      result->append(acl_user->auth_string.str, acl_user->auth_string.length);
+      result->append(&acl_user->auth_string);
       result->append('\'');
     }
   }
diff --git a/sql/sql_load.cc b/sql/sql_load.cc
index 8550fc187c1..e3c46515c4d 100644
--- a/sql/sql_load.cc
+++ b/sql/sql_load.cc
@@ -837,7 +837,7 @@ static bool write_execute_load_query_log_event(THD *thd, sql_exchange* ex,
       if (n++)
         query_str.append(STRING_WITH_LEN(", "));
       append_identifier(thd, &query_str, item->name.str, item->name.length);
-      query_str.append(val->name.str, val->name.length);
+      query_str.append(&val->name);
     }
   }
 
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 3e29853d703..00f009feb4a 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -7644,28 +7644,23 @@ mysql_new_select(LEX *lex, bool move_down, SELECT_LEX *select_lex)
   @param var_name		Variable name
 */
 
-void create_select_for_variable(const char *var_name)
+void create_select_for_variable(THD *thd, LEX_CSTRING *var_name)
 {
-  THD *thd;
   LEX *lex;
-  LEX_CSTRING tmp;
   Item *var;
   char buff[MAX_SYS_VAR_LENGTH*2+4+8], *end;
   DBUG_ENTER("create_select_for_variable");
 
-  thd= current_thd;
   lex= thd->lex;
   mysql_init_select(lex);
   lex->sql_command= SQLCOM_SELECT;
-  tmp.str= var_name;
-  tmp.length=strlen(var_name);
   /*
     We set the name of Item to @@session.var_name because that then is used
     as the column name in the output.
   */
-  if ((var= get_system_var(thd, OPT_SESSION, tmp, null_clex_str)))
+  if ((var= get_system_var(thd, OPT_SESSION, var_name, &null_clex_str)))
   {
-    end= strxmov(buff, "@@session.", var_name, NullS);
+    end= strxmov(buff, "@@session.", var_name->str, NullS);
     var->set_name(thd, buff, end-buff, system_charset_info);
     add_item_to_list(thd, var);
   }
diff --git a/sql/sql_parse.h b/sql/sql_parse.h
index 02318442686..b0371a2cb81 100644
--- a/sql/sql_parse.h
+++ b/sql/sql_parse.h
@@ -93,7 +93,7 @@ void mysql_parse(THD *thd, char *rawbuf, uint length,
                  Parser_state *parser_state, bool is_com_multi,
                  bool is_next_command);
 bool mysql_new_select(LEX *lex, bool move_down, SELECT_LEX *sel);
-void create_select_for_variable(const char *var_name);
+void create_select_for_variable(THD *thd, LEX_CSTRING *var_name);
 void create_table_set_open_action_and_adjust_tables(LEX *lex);
 void mysql_init_multi_delete(LEX *lex);
 bool multi_delete_set_locks_and_link_aux_tables(LEX *lex);
diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index 7e29d7867b9..6d9f3f23138 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -1773,7 +1773,7 @@ static void append_create_options(THD *thd, String *packet,
     if (opt->quoted_value)
       append_unescaped(packet, opt->value.str, opt->value.length);
     else
-      packet->append(opt->value.str, opt->value.length);
+      packet->append(&opt->value);
   }
   if (in_comment)
     packet->append(STRING_WITH_LEN(" */"));
@@ -7089,7 +7089,7 @@ static int get_schema_partitions_record(THD *thd, TABLE_LIST *tables,
         tmp_res.length(0);
         if (part_elem->has_null_value)
         {
-          tmp_str.append("NULL");
+          tmp_str.append(STRING_WITH_LEN("NULL"));
           if (num_items > 0)
             tmp_str.append(",");
         }
@@ -7098,7 +7098,7 @@ static int get_schema_partitions_record(THD *thd, TABLE_LIST *tables,
           if (part_info->column_list)
           {
             if (part_info->part_field_list.elements > 1U)
-              tmp_str.append("(");
+              tmp_str.append(STRING_WITH_LEN("("));
             if (get_partition_column_description(thd,
                                                  part_info,
                                                  list_value,
diff --git a/sql/sql_string.h b/sql/sql_string.h
index 1551ef361f3..5dbb110135f 100644
--- a/sql/sql_string.h
+++ b/sql/sql_string.h
@@ -575,6 +575,10 @@ public:
   {
     qs_append(str, (uint32)strlen(str));
   }
+  void qs_append(const LEX_CSTRING *str)
+  {
+    qs_append(str->str, str->length);
+  }
   void qs_append(const char *str, uint32 len);
   void qs_append_hex(const char *str, uint32 len);
   void qs_append(double d);
diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc
index 502d151a60a..7e3f047ef91 100644
--- a/sql/sql_trigger.cc
+++ b/sql/sql_trigger.cc
@@ -688,7 +688,7 @@ static void build_trig_stmt_query(THD *thd, TABLE_LIST *tables,
 
   /* Create statement for storing trigger (without trigger order) */
   if (lex->trg_chistics.ordering_clause == TRG_ORDER_NONE)
-    trigger_def->append(stmt_definition.str, stmt_definition.length);
+    trigger_def->append(&stmt_definition);
   else
   {
     /* Copy data before FOLLOWS/PRECEDES trigger_name */
@@ -923,8 +923,8 @@ err_without_cleanup:
   if (trigger_dropped)
   {
     String drop_trg_query;
-    drop_trg_query.append("DROP TRIGGER /* generated by failed CREATE TRIGGER */ ");
-    drop_trg_query.append(lex->spname->m_name.str);
+    drop_trg_query.append(STRING_WITH_LEN("DROP TRIGGER /* generated by failed CREATE TRIGGER */ "));
+    drop_trg_query.append(&lex->spname->m_name);
     /*
       We dropped an existing trigger and was not able to recreate it because
       of an internal error. Ensure it's also dropped on the slave.
diff --git a/sql/sql_view.cc b/sql/sql_view.cc
index d6b972d2d73..0547a3cb343 100644
--- a/sql/sql_view.cc
+++ b/sql/sql_view.cc
@@ -647,8 +647,7 @@ bool mysql_create_view(THD *thd, TABLE_LIST *views,
        { C_STRING_WITH_LEN("ALTER ") },
        { C_STRING_WITH_LEN("CREATE OR REPLACE ") }};
 
-    buff.append(command[thd->lex->create_view->mode].str,
-                command[thd->lex->create_view->mode].length);
+    buff.append(&command[thd->lex->create_view->mode]);
     view_store_options(thd, views, &buff);
     buff.append(STRING_WITH_LEN("VIEW "));
 
@@ -680,7 +679,7 @@ bool mysql_create_view(THD *thd, TABLE_LIST *views,
       buff.append(')');
     }
     buff.append(STRING_WITH_LEN(" AS "));
-    buff.append(views->source.str, views->source.length);
+    buff.append(&views->source);
 
     int errcode= query_error_code(thd, TRUE);
     /*
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index e337b624e4c..e02e5f9d5f1 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -10726,7 +10726,7 @@ variable_aux:
               thd->parse_error();
               MYSQL_YYABORT;
             }
-            if (!($$= get_system_var(thd, $2, $3, $4)))
+            if (!($$= get_system_var(thd, $2, &$3, &$4)))
               MYSQL_YYABORT;
             if (!((Item_func_get_system_var*) $$)->is_written_to_binlog())
               Lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_SYSTEM_VARIABLE);
@@ -13035,9 +13035,15 @@ show_param:
             lex->sql_command= SQLCOM_SHOW_PRIVILEGES;
           }
         | COUNT_SYM '(' '*' ')' WARNINGS
-          { (void) create_select_for_variable("warning_count"); }
+          {
+            LEX_CSTRING var= {STRING_WITH_LEN("warning_count")};
+            (void) create_select_for_variable(thd, &var);
+          }
         | COUNT_SYM '(' '*' ')' ERRORS
-          { (void) create_select_for_variable("error_count"); }
+          {
+            LEX_CSTRING var= {STRING_WITH_LEN("error_count")};
+            (void) create_select_for_variable(thd, &var);
+          }
         | WARNINGS opt_limit_clause
           { Lex->sql_command = SQLCOM_SHOW_WARNS;}
         | ERRORS opt_limit_clause
diff --git a/sql/sql_yacc_ora.yy b/sql/sql_yacc_ora.yy
index 4a093373b49..b25baab22fb 100644
--- a/sql/sql_yacc_ora.yy
+++ b/sql/sql_yacc_ora.yy
@@ -10781,7 +10781,7 @@ variable_aux:
               thd->parse_error();
               MYSQL_YYABORT;
             }
-            if (!($$= get_system_var(thd, $2, $3, $4)))
+            if (!($$= get_system_var(thd, $2, &$3, &$4)))
               MYSQL_YYABORT;
             if (!((Item_func_get_system_var*) $$)->is_written_to_binlog())
               Lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_SYSTEM_VARIABLE);
@@ -13123,9 +13123,15 @@ show_param:
             lex->sql_command= SQLCOM_SHOW_PRIVILEGES;
           }
         | COUNT_SYM '(' '*' ')' WARNINGS
-          { (void) create_select_for_variable("warning_count"); }
+          {
+            LEX_CSTRING var= {STRING_WITH_LEN("warning_count")};
+            (void) create_select_for_variable(thd, &var);
+          }
         | COUNT_SYM '(' '*' ')' ERRORS
-          { (void) create_select_for_variable("error_count"); }
+          {
+            LEX_CSTRING var= {STRING_WITH_LEN("error_count")};
+            (void) create_select_for_variable(thd, &var);
+          }
         | WARNINGS opt_limit_clause
           { Lex->sql_command = SQLCOM_SHOW_WARNS;}
         | ERRORS opt_limit_clause
diff --git a/sql/unireg.cc b/sql/unireg.cc
index cc5e19d1104..5b970b3c555 100644
--- a/sql/unireg.cc
+++ b/sql/unireg.cc
@@ -539,7 +539,7 @@ static bool pack_expression(String *buf, Virtual_column_info *vcol,
   size_t len_off= buf->length();
   buf->q_append2b(0); // to be added later
   buf->q_append((char)vcol->name.length);
-  buf->q_append(vcol->name.str, vcol->name.length);
+  buf->q_append(&vcol->name);
   size_t expr_start= buf->length();
   vcol->print(buf);
   size_t expr_len= buf->length() - expr_start;
diff --git a/sql/wsrep_mysqld.cc b/sql/wsrep_mysqld.cc
index 05ec182b318..e64ce00cd47 100644
--- a/sql/wsrep_mysqld.cc
+++ b/sql/wsrep_mysqld.cc
@@ -1325,22 +1325,17 @@ create_view_query(THD *thd, uchar** buf, size_t* buf_len)
     SELECT_LEX *select_lex= &lex->select_lex;
     TABLE_LIST *first_table= select_lex->table_list.first;
     TABLE_LIST *views = first_table;
-
+    LEX_USER *definer;
     String buff;
     const LEX_STRING command[3]=
       {{ C_STRING_WITH_LEN("CREATE ") },
        { C_STRING_WITH_LEN("ALTER ") },
        { C_STRING_WITH_LEN("CREATE OR REPLACE ") }};
 
-    buff.append(command[thd->lex->create_view->mode].str,
-                command[thd->lex->create_view->mode].length);
-
-    LEX_USER *definer;
+    buff.append(&command[thd->lex->create_view->mode]);
 
     if (lex->definer)
-    {
       definer= get_current_user(thd, lex->definer);
-    }
     else
     {
       /*
diff --git a/storage/connect/json.h b/storage/connect/json.h
index 685c1dddcf2..de3288b1b58 100644
--- a/storage/connect/json.h
+++ b/storage/connect/json.h
@@ -52,6 +52,8 @@ PSZ   Serialize(PGLOBAL g, PJSON jsp, char *fn, int pretty);
 bool  SerializeArray(JOUT *js, PJAR jarp, bool b);
 bool  SerializeObject(JOUT *js, PJOB jobp);
 bool  SerializeValue(JOUT *js, PJVAL jvp);
+bool IsNum(PSZ s);
+char *NextChr(PSZ s, char sep);
 
 /***********************************************************************/
 /* Class JOUT. Used by Serialize.                                      */
diff --git a/storage/connect/jsonudf.cpp b/storage/connect/jsonudf.cpp
index b44e9c1309b..00139b4b820 100644
--- a/storage/connect/jsonudf.cpp
+++ b/storage/connect/jsonudf.cpp
@@ -1815,7 +1815,7 @@ char *json_make_array(UDF_INIT *initid, UDF_ARGS *args, char *result,
   return str;
 } // end of json_make_array
 
-void json_array_deinit(UDF_INIT* initid)
+static void json_array_deinit(UDF_INIT* initid)
 {
   JsonFreeMem((PGLOBAL)initid->ptr);
 } // end of json_make_array_deinit
diff --git a/storage/connect/tabjson.cpp b/storage/connect/tabjson.cpp
index 823c82b9ceb..84c3947b68b 100644
--- a/storage/connect/tabjson.cpp
+++ b/storage/connect/tabjson.cpp
@@ -53,8 +53,6 @@
 /*  External functions.                                                */
 /***********************************************************************/
 USETEMP UseTemp(void);
-bool    IsNum(PSZ s);
-char   *NextChr(PSZ s, char sep);
 
 typedef struct _jncol {
   struct _jncol *Next;