Merge 10.4 into 10.5

18 files changed, 244 insertions, 88 deletions

diff --git a/sql/item_func.cc b/sql/item_func.cc
index dc1de8a8e9f..8a75d2c9946 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -2245,35 +2245,54 @@ bool Item_func_bit_neg::fix_length_and_dec()
 
 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);
   /*
-    The INT branch of this code should be revised.
-    It creates too large data types, e.g.
-      CREATE OR REPLACE TABLE t2 AS SELECT FLOOR(9999999.999) AS fa;
-    results in a BININT(10) column, while INT(7) should probably be enough.
+    FLOOR() for negative numbers can increase length:   floor(-9.9) -> -10
+    CEILING() for positive numbers can increase length:  ceil(9.9)  -> 10
   */
-  ulonglong tmp_max_length= (ulonglong ) args[0]->max_length - 
-    (args[0]->decimals ? args[0]->decimals + 1 : 0) + 2;
-  max_length= tmp_max_length > (ulonglong) UINT_MAX32 ?
-    (uint32) UINT_MAX32 : (uint32) tmp_max_length;
-  uint tmp= float_length(decimals);
-  set_if_smaller(max_length,tmp);
-  decimals= 0;
+  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);
 
   /*
-    -2 because in most high position can't be used any digit for longlong
-    and one position for increasing value during operation
+    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 (args[0]->max_length - args[0]->decimals >= DECIMAL_LONGLONG_DIGITS - 2)
+  if (precision > 18)
   {
+    unsigned_flag= args[0]->unsigned_flag;
     fix_char_length(
-      my_decimal_precision_to_length_no_truncation(
-        args[0]->decimal_int_part(), 0, false));
+      my_decimal_precision_to_length_no_truncation(precision, 0,
+                                                   unsigned_flag));
     set_handler(&type_handler_newdecimal);
   }
   else
   {
-    unsigned_flag= args[0]->unsigned_flag;
-    set_handler(type_handler_long_or_longlong());
+    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);
+    }
   }
 }
 
diff --git a/sql/item_func.h b/sql/item_func.h
index f39caa46ffd..5b4acdce1c6 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -1838,6 +1838,7 @@ public:
   Item_func_int_val(THD *thd, Item *a): Item_func_hybrid_field_type(thd, a) {}
   bool check_partition_func_processor(void *int_arg) { return FALSE; }
   bool check_vcol_func_processor(void *arg) { return FALSE; }
+  virtual decimal_round_mode round_mode() const= 0;
   void fix_length_and_dec_double();
   void fix_length_and_dec_int_or_decimal();
   void fix_length_and_dec_time()
@@ -1866,6 +1867,7 @@ class Item_func_ceiling :public Item_func_int_val
 public:
   Item_func_ceiling(THD *thd, Item *a): Item_func_int_val(thd, a) {}
   const char *func_name() const { return "ceiling"; }
+  decimal_round_mode round_mode() const { return CEILING; }
   longlong int_op();
   double real_op();
   my_decimal *decimal_op(my_decimal *);
@@ -1881,6 +1883,7 @@ class Item_func_floor :public Item_func_int_val
 public:
   Item_func_floor(THD *thd, Item *a): Item_func_int_val(thd, a) {}
   const char *func_name() const { return "floor"; }
+  decimal_round_mode round_mode() const { return FLOOR; }
   longlong int_op();
   double real_op();
   my_decimal *decimal_op(my_decimal *);
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 176a6e6efc9..58f41ecfbbc 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -2642,18 +2642,42 @@ String *Item_func_soundex::val_str(String *str)
   This should be 'internationalized' sometimes.
 */
 
-const int FORMAT_MAX_DECIMALS= 30;
+/*
+  The maximum supported decimal scale:
+  38 - starting from 10.2.1
+  30 - before 10.2.1
+*/
+const int FORMAT_MAX_DECIMALS= 38;
 
 
 bool Item_func_format::fix_length_and_dec()
 {
   uint32 char_length= args[0]->type_handler()->Item_decimal_notation_int_digits(args[0]);
   uint dec= FORMAT_MAX_DECIMALS;
-  if (args[1]->const_item() && !args[1]->is_expensive() && !args[1]->null_value)
+  /*
+    Format can require one more integer digit if rounding happens:
+      FORMAT(9.9,0) -> '10'
+    Set need_extra_digit_for_rounding to true by default
+    if args[0] has some decimals: if args[1] is not
+    a constant, then format can potentially reduce
+    the number of decimals and round to the next integer.
+  */
+  bool need_extra_digit_for_rounding= args[0]->decimals > 0;
+  if (args[1]->const_item() && !args[1]->is_expensive())
   {
     Longlong_hybrid tmp= args[1]->to_longlong_hybrid();
-    dec= tmp.to_uint(FORMAT_MAX_DECIMALS);
+    if (!args[1]->null_value)
+    {
+      dec= tmp.to_uint(FORMAT_MAX_DECIMALS);
+      need_extra_digit_for_rounding= (dec < args[0]->decimals);
+    }
   }
+  /*
+    In case of a data type with zero integer digits, e.g. DECIMAL(4,4),
+    we'll print at least one integer digit.
+  */
+  if (need_extra_digit_for_rounding || !char_length)
+    char_length++;
   uint32 max_sep_count= (char_length / 3) + (dec ? 1 : 0) + /*sign*/1;
   collation.set(default_charset());
   fix_char_length(char_length + max_sep_count + dec);
@@ -2709,7 +2733,7 @@ String *Item_func_format::val_str_ascii(String *str)
     if ((null_value=args[0]->null_value))
       return 0; /* purecov: inspected */
     nr= my_double_round(nr, (longlong) dec, FALSE, FALSE);
-    str->set_real(nr, dec, &my_charset_numeric);
+    str->set_fcvt(nr, dec);
     if (!std::isfinite(nr))
       return str;
     str_length=str->length();
diff --git a/sql/item_subselect.h b/sql/item_subselect.h
index b5823dfb194..7e504d09565 100644
--- a/sql/item_subselect.h
+++ b/sql/item_subselect.h
@@ -149,6 +149,10 @@ public:
   Item_subselect(THD *thd);
 
   virtual subs_type substype() { return UNKNOWN_SUBS; }
+  bool is_exists_predicate()
+  {
+    return substype() == Item_subselect::EXISTS_SUBS;
+  }
   bool is_in_predicate()
   {
     return get_IN_subquery() != NULL;
diff --git a/sql/records.cc b/sql/records.cc
index e1766322e2f..900eacf5943 100644
--- a/sql/records.cc
+++ b/sql/records.cc
@@ -350,12 +350,9 @@ bool init_read_record(READ_RECORD *info,THD *thd, TABLE *table,
 
 
 void end_read_record(READ_RECORD *info)
-{                   /* free cache if used */
-  if (info->cache)
-  {
-    my_free_lock(info->cache);
-    info->cache=0;
-  }
+{
+  /* free cache if used */
+  free_cache(info);
   if (info->table)
   {
     if (info->table->is_created())
@@ -366,6 +363,17 @@ void end_read_record(READ_RECORD *info)
   }
 }
 
+
+void free_cache(READ_RECORD *info)
+{
+  if (info->cache)
+  {
+    my_free_lock(info->cache);
+    info->cache=0;
+  }
+}
+
+
 static int rr_handle_error(READ_RECORD *info, int error)
 {
   if (info->thd->killed)
diff --git a/sql/records.h b/sql/records.h
index 04dc06b3c74..272bbd0d9b5 100644
--- a/sql/records.h
+++ b/sql/records.h
@@ -31,6 +31,7 @@ class SORT_INFO;
 struct READ_RECORD;
 
 void end_read_record(READ_RECORD *info);
+void free_cache(READ_RECORD *info);
 
 /**
   A context for reading through a single table using a chosen access method:
diff --git a/sql/share/errmsg-utf8.txt b/sql/share/errmsg-utf8.txt
index 63df3a6b956..79c27a37e6d 100644
--- a/sql/share/errmsg-utf8.txt
+++ b/sql/share/errmsg-utf8.txt
@@ -3244,25 +3244,25 @@ ER_NONEXISTING_GRANT 42000
         swe "Det finns inget privilegium definierat för användare '%-.48s' på '%-.64s'"
         ukr "Повноважень не визначено для користувача '%-.48s' з хосту '%-.64s'"
 ER_TABLEACCESS_DENIED_ERROR 42000 
-        cze "%-.32s příkaz nepřístupný pro uživatele: '%s'@'%s' pro tabulku '%-.192s'"
-        dan "%-.32s-kommandoen er ikke tilladt for brugeren '%s'@'%s' for tabellen '%-.192s'"
-        nla "%-.32s commando geweigerd voor gebruiker: '%s'@'%s' voor tabel '%-.192s'"
-        eng "%-.32s command denied to user '%s'@'%s' for table '%-.192s'"
-        jps "コマンド %-.32s は ユーザー '%s'@'%s' ,テーブル '%-.192s' に対して許可されていません",
-        est "%-.32s käsk ei ole lubatud kasutajale '%s'@'%s' tabelis '%-.192s'"
-        fre "La commande '%-.32s' est interdite à l'utilisateur: '%s'@'%s' sur la table '%-.192s'"
-        ger "%-.32s Befehl nicht erlaubt für Benutzer '%s'@'%s' auf Tabelle '%-.192s'"
-        hun "%-.32s parancs a '%s'@'%s' felhasznalo szamara nem engedelyezett a '%-.192s' tablaban"
-        ita "Comando %-.32s negato per l'utente: '%s'@'%s' sulla tabella '%-.192s'"
-        jpn "コマンド %-.32s は ユーザー '%s'@'%s' ,テーブル '%-.192s' に対して許可されていません"
-        kor "'%-.32s' 명령은 다음 사용자에게 거부되었습니다. : '%s'@'%s' for 테이블 '%-.192s'"
-        por "Comando '%-.32s' negado para o usuário '%s'@'%s' na tabela '%-.192s'"
-        rum "Comanda %-.32s interzisa utilizatorului: '%s'@'%s' pentru tabela '%-.192s'"
-        rus "Команда %-.32s запрещена пользователю '%s'@'%s' для таблицы '%-.192s'"
-        serbian "%-.32s komanda zabranjena za korisnika '%s'@'%s' za tabelu '%-.192s'"
-        spa "%-.32s comando negado para usuario: '%s'@'%s' para tabla '%-.192s'"
-        swe "%-.32s ej tillåtet för '%s'@'%s' för tabell '%-.192s'"
-        ukr "%-.32s команда заборонена користувачу: '%s'@'%s' у таблиці '%-.192s'"
+        cze "%-.100T příkaz nepřístupný pro uživatele: '%s'@'%s' pro tabulku '%-.192s'"
+        dan "%-.100T-kommandoen er ikke tilladt for brugeren '%s'@'%s' for tabellen '%-.192s'"
+        nla "%-.100T commando geweigerd voor gebruiker: '%s'@'%s' voor tabel '%-.192s'"
+        eng "%-.100T command denied to user '%s'@'%s' for table '%-.192s'"
+        jps "コマンド %-.100T は ユーザー '%s'@'%s' ,テーブル '%-.192s' に対して許可されていません",
+        est "%-.100T käsk ei ole lubatud kasutajale '%s'@'%s' tabelis '%-.192s'"
+        fre "La commande '%-.100T' est interdite à l'utilisateur: '%s'@'%s' sur la table '%-.192s'"
+        ger "%-.100T Befehl nicht erlaubt für Benutzer '%s'@'%s' auf Tabelle '%-.192s'"
+        hun "%-.100T parancs a '%s'@'%s' felhasznalo szamara nem engedelyezett a '%-.192s' tablaban"
+        ita "Comando %-.100T negato per l'utente: '%s'@'%s' sulla tabella '%-.192s'"
+        jpn "コマンド %-.100T は ユーザー '%s'@'%s' ,テーブル '%-.192s' に対して許可されていません"
+        kor "'%-.100T' 명령은 다음 사용자에게 거부되었습니다. : '%s'@'%s' for 테이블 '%-.192s'"
+        por "Comando '%-.100T' negado para o usuário '%s'@'%s' na tabela '%-.192s'"
+        rum "Comanda %-.100T interzisa utilizatorului: '%s'@'%s' pentru tabela '%-.192s'"
+        rus "Команда %-.100T запрещена пользователю '%s'@'%s' для таблицы '%-.192s'"
+        serbian "%-.100T komanda zabranjena za korisnika '%s'@'%s' za tabelu '%-.192s'"
+        spa "%-.100T comando negado para usuario: '%s'@'%s' para tabla '%-.192s'"
+        swe "%-.100T ej tillåtet för '%s'@'%s' för tabell '%-.192s'"
+        ukr "%-.100T команда заборонена користувачу: '%s'@'%s' у таблиці '%-.192s'"
 ER_COLUMNACCESS_DENIED_ERROR 42000 
         cze "%-.32s příkaz nepřístupný pro uživatele: '%s'@'%s' pro sloupec '%-.192s' v tabulce '%-.192s'"
         dan "%-.32s-kommandoen er ikke tilladt for brugeren '%s'@'%s' for kolonne '%-.192s' in tabellen '%-.192s'"
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index a65acc2c87e..37def6df7ed 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -2812,8 +2812,17 @@ int Lex_input_stream::scan_ident_delimited(THD *thd,
   uchar c;
   DBUG_ASSERT(m_ptr == m_tok_start + 1);
 
-  while ((c= yyGet()))
+  for ( ; ; )
   {
+    if (!(c= yyGet()))
+    {
+      /*
+        End-of-query or straight 0x00 inside a delimited identifier.
+        Return the quote character, to have the parser fail on syntax error.
+      */
+      m_ptr= (char *) m_tok_start + 1;
+      return quote_char;
+    }
     int var_length= cs->charlen(get_ptr() - 1, get_end_of_query());
     if (var_length == 1)
     {
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index b0c4db47494..5dbe01c5044 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -13885,24 +13885,7 @@ void JOIN::cleanup(bool full)
       for (tab= first_linear_tab(this, WITH_BUSH_ROOTS, WITH_CONST_TABLES); tab;
            tab= next_linear_tab(this, tab, WITH_BUSH_ROOTS))
       {
-        if (!tab->table)
-          continue;
-        DBUG_PRINT("info", ("close index: %s.%s  alias: %s",
-                            tab->table->s->db.str,
-                            tab->table->s->table_name.str,
-                            tab->table->alias.c_ptr()));
-	if (tab->table->is_created())
-        {
-          tab->table->file->ha_index_or_rnd_end();
-          if (tab->aggr)
-          {
-            int tmp= 0;
-            if ((tmp= tab->table->file->extra(HA_EXTRA_NO_CACHE)))
-              tab->table->file->print_error(tmp, MYF(0));
-          }
-        }
-        delete tab->filesort_result;
-        tab->filesort_result= NULL;
+        tab->partial_cleanup();
       }
     }
   }
@@ -29035,6 +29018,40 @@ void JOIN::handle_implicit_grouping_with_window_funcs()
 }
 
 
+
+/*
+  @brief
+    Perform a partial cleanup for the JOIN_TAB structure
+
+  @note
+    this is used to cleanup resources for the re-execution of correlated
+    subqueries.
+*/
+void JOIN_TAB::partial_cleanup()
+{
+  if (!table)
+    return;
+
+  if (table->is_created())
+  {
+    table->file->ha_index_or_rnd_end();
+    DBUG_PRINT("info", ("close index: %s.%s  alias: %s",
+               table->s->db.str,
+               table->s->table_name.str,
+               table->alias.c_ptr()));
+    if (aggr)
+    {
+      int tmp= 0;
+      if ((tmp= table->file->extra(HA_EXTRA_NO_CACHE)))
+        table->file->print_error(tmp, MYF(0));
+    }
+  }
+  delete filesort_result;
+  filesort_result= NULL;
+  free_cache(&read_record);
+}
+
+
 /**
   @brief
     Look for provision of the select_handler interface by a foreign engine
diff --git a/sql/sql_select.h b/sql/sql_select.h
index 545db41798c..7c8908302cd 100644
--- a/sql/sql_select.h
+++ b/sql/sql_select.h
@@ -673,6 +673,8 @@ typedef struct st_join_table {
   bool use_order() const; ///< Use ordering provided by chosen index?
   bool sort_table();
   bool remove_duplicates();
+
+  void partial_cleanup();
   void add_keyuses_for_splitting();
   SplM_plan_info *choose_best_splitting(double record_count,
                                         table_map remaining_tables);
diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index 6dd013d929e..0d41857aaf5 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -4620,7 +4620,7 @@ fill_schema_table_by_open(THD *thd, MEM_ROOT *mem_root,
     Again we don't do this for SHOW COLUMNS/KEYS because
     of backward compatibility.
   */
-  if (!is_show_fields_or_keys && result &&
+  if (!is_show_fields_or_keys && result && thd->is_error() &&
       (thd->get_stmt_da()->sql_errno() == ER_NO_SUCH_TABLE ||
        thd->get_stmt_da()->sql_errno() == ER_WRONG_OBJECT ||
        thd->get_stmt_da()->sql_errno() == ER_NOT_SEQUENCE))
@@ -5932,12 +5932,12 @@ static int get_schema_column_record(THD *thd, TABLE_LIST *tables,
         I.e. we are in SELECT FROM INFORMATION_SCHEMA.COLUMS
         rather than in SHOW COLUMNS
       */
-      convert_error_to_warning(thd);
+      if (thd->is_error())
+        convert_error_to_warning(thd);
       res= 0;
     }
     DBUG_RETURN(res);
   }
-
   show_table= tables->table;
   count= 0;
   ptr= show_table->field;
diff --git a/sql/sql_string.cc b/sql/sql_string.cc
index 030075aa793..e2defba434d 100644
--- a/sql/sql_string.cc
+++ b/sql/sql_string.cc
@@ -183,6 +183,17 @@ bool Binary_string::set_hex(const char *str, uint32 len)
 }
 
 
+bool Binary_string::set_fcvt(double num, uint decimals)
+{
+  // Assert that `decimals` is small enough to fit into FLOATING_POINT_BUFFER
+  DBUG_ASSERT(decimals < DECIMAL_NOT_SPECIFIED);
+  if (alloc(FLOATING_POINT_BUFFER))
+    return true;
+  length(my_fcvt(num, decimals, Ptr, NULL));
+  return false;
+}
+
+
 bool String::set_real(double num,uint decimals, CHARSET_INFO *cs)
 {
   char buff[FLOATING_POINT_BUFFER];
diff --git a/sql/sql_string.h b/sql/sql_string.h
index 37e9c40db61..2ef817ea0ad 100644
--- a/sql/sql_string.h
+++ b/sql/sql_string.h
@@ -524,6 +524,7 @@ public:
 
   bool set_hex(ulonglong num);
   bool set_hex(const char *str, uint32 len);
+  bool set_fcvt(double num, uint decimals);
 
   bool copy();                                  // Alloc string if not alloced
   bool copy(const Binary_string &s);            // Allocate new string
@@ -781,6 +782,11 @@ public:
   bool set(longlong num, CHARSET_INFO *cs) { return set_int(num, false, cs); }
   bool set(ulonglong num, CHARSET_INFO *cs) { return set_int((longlong)num, true, cs); }
   bool set_real(double num,uint decimals, CHARSET_INFO *cs);
+  bool set_fcvt(double num, uint decimals)
+  {
+    set_charset(&my_charset_latin1);
+    return Binary_string::set_fcvt(num, decimals);
+  }
 
   bool set_hex(ulonglong num)
   {
diff --git a/sql/sql_type.cc b/sql/sql_type.cc
index 593062646ce..9e0f9b013c0 100644
--- a/sql/sql_type.cc
+++ b/sql/sql_type.cc
@@ -4647,6 +4647,7 @@ bool Type_handler_temporal_result::
        Item_func_min_max_fix_attributes(THD *thd, Item_func_min_max *func,
                                         Item **items, uint nitems) const
 {
+  DBUG_ASSERT(func->field_type() != MYSQL_TYPE_DATE);
   bool rc= Type_handler::Item_func_min_max_fix_attributes(thd, func,
                                                           items, nitems);
   bool is_time= func->field_type() == MYSQL_TYPE_TIME;
@@ -4701,7 +4702,6 @@ bool Type_handler_temporal_result::
         DATETIME             DATETIME       no conversion
         DATETIME             TIMESTAMP      safe conversion
         DATETIME             DATE           safe conversion
-        DATE                 DATE           no conversion
         TIME                 TIME           no conversion
 
         Note, a function cannot return TIMESTAMP if it has non-TIMESTAMP
@@ -4718,9 +4718,6 @@ bool Type_handler_temporal_result::
       -------------------- ------------- -------
       TIMESTAMP            TIME          Not possible
       DATETIME             TIME          depends on OLD_MODE_ZERO_DATE_TIME_CAST
-      DATE                 TIMESTAMP     Not possible
-      DATE                 DATETIME      Not possible
-      DATE                 TIME          Not possible
       TIME                 TIMESTAMP     Not possible
       TIME                 DATETIME      Not possible
       TIME                 DATE          Not possible
@@ -4743,6 +4740,30 @@ bool Type_handler_temporal_result::
 }
 
 
+bool Type_handler_date_common::
+       Item_func_min_max_fix_attributes(THD *thd, Item_func_min_max *func,
+                                        Item **items, uint nitems) const
+{
+  func->fix_attributes_date();
+  if (func->maybe_null)
+    return false;
+  /*
+    We cannot trust the generic maybe_null value calculated during fix_fields().
+    If a conversion from non-temoral types to DATE happens,
+    then the result can be NULL (even if all arguments are not NULL).
+  */
+  for (uint i= 0; i < nitems; i++)
+  {
+    if (items[i]->type_handler()->cmp_type() != TIME_RESULT)
+    {
+      func->maybe_null= true;
+      break;
+    }
+  }
+  return false;
+}
+
+
 bool Type_handler_real_result::
        Item_func_min_max_fix_attributes(THD *thd, Item_func_min_max *func,
                                         Item **items, uint nitems) const
diff --git a/sql/sql_type.h b/sql/sql_type.h
index 02abd55680d..a6d85b5bb47 100644
--- a/sql/sql_type.h
+++ b/sql/sql_type.h
@@ -6145,8 +6145,11 @@ public:
                                        const char *name,
                                        Type_handler_hybrid_field_type *,
                                        Type_all_attributes *atrr,
-                                       Item **items, uint nitems)
-                                       const override;
+                                       Item **items, uint nitems) const
+    override;
+  bool Item_func_min_max_fix_attributes(THD *thd, Item_func_min_max *func,
+                                        Item **items, uint nitems) const
+    override;
   void Item_param_set_param_func(Item_param *param,
                                  uchar **pos, ulong len) const override;
 };
diff --git a/sql/sql_union.cc b/sql/sql_union.cc
index 3360c3c18cb..f1df76508d7 100644
--- a/sql/sql_union.cc
+++ b/sql/sql_union.cc
@@ -1,5 +1,5 @@
 /* Copyright (c) 2000, 2017, Oracle and/or its affiliates.
-   Copyright (c) 2010, 2017, Corporation
+   Copyright (c) 2010, 2020, 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
@@ -1364,6 +1364,25 @@ bool st_select_lex_unit::prepare(TABLE_LIST *derived_arg,
   found_rows_for_union= first_sl->options & OPTION_FOUND_ROWS;
   is_union_select= is_unit_op() || fake_select_lex || single_tvc;
 
+  /*
+    If we are reading UNION output and the UNION is in the
+    IN/ANY/ALL/EXISTS subquery, then ORDER BY is redundant and hence should
+    be removed.
+    Example:
+     select ... col IN (select col2 FROM t1 union select col3 from t2 ORDER BY 1)
+
+    (as for ORDER BY ... LIMIT, it currently not supported inside
+     IN/ALL/ANY subqueries)
+    (For non-UNION this removal of ORDER BY clause is done in
+     check_and_do_in_subquery_rewrites())
+  */
+  if (item && is_unit_op() &&
+      (item->is_in_predicate() || item->is_exists_predicate()))
+  {
+    global_parameters()->order_list.first= NULL;
+    global_parameters()->order_list.elements= 0;
+  }
+
   /* will only optimize once */
   if (!bag_set_op_optimized && !is_recursive)
   {
@@ -1390,6 +1409,7 @@ bool st_select_lex_unit::prepare(TABLE_LIST *derived_arg,
       break;
     }
   }
+
   /* Global option */
 
   if (is_union_select || is_recursive)
diff --git a/sql/table.h b/sql/table.h
index 7ce6db5b193..7edf1e68a0b 100644
--- a/sql/table.h
+++ b/sql/table.h
@@ -1388,9 +1388,16 @@ public:
   /* number of select if it is derived table */
   uint          derived_select_number;
   /*
-    0 or JOIN_TYPE_{LEFT|RIGHT}. Currently this is only compared to 0.
-    If maybe_null !=0, this table is inner w.r.t. some outer join operation,
-    and null_row may be true.
+    Possible values:
+     - 0 by default
+     - JOIN_TYPE_{LEFT|RIGHT} if the table is inner w.r.t an outer join
+       operation
+     - 1 if the SELECT has mixed_implicit_grouping=1. example:
+       select max(col1), col2 from t1. In this case, the query produces
+       one row with all columns having NULL values.
+
+    Interpetation: If maybe_null!=0, all fields of the table are considered
+    NULLable (and have NULL values when null_row=true)
   */
   uint maybe_null;
   int		current_lock;           /* Type of lock on table */
diff --git a/sql/tztime.cc b/sql/tztime.cc
index b1c0c79d5d7..4546f2291cd 100644
--- a/sql/tztime.cc
+++ b/sql/tztime.cc
@@ -2719,6 +2719,7 @@ main(int argc, char **argv)
   }
 
   if (opt_skip_write_binlog)
+  {
     /* If skip_write_binlog is set and wsrep is compiled in we disable
        sql_log_bin and wsrep_on to avoid Galera replicating below
        truncate table clauses. This will allow user to set different
@@ -2726,15 +2727,9 @@ main(int argc, char **argv)
     printf("set @prep1=if((select count(*) from information_schema.global_variables where variable_name='wsrep_on' and variable_value='ON'), 'SET SESSION SQL_LOG_BIN=?, WSREP_ON=OFF;', 'do ?');\n"
            "prepare set_wsrep_write_binlog from @prep1;\n"
            "set @toggle=0; execute set_wsrep_write_binlog using @toggle;\n");
-
-  if (argc == 1 && !opt_leap)
+  }
+  else
   {
-    /* Argument is timezonedir */
-
-    root_name_end= strmake_buf(fullname, argv[0]);
-
-    if(!opt_skip_write_binlog)
-    {
       // Alter time zone tables to InnoDB if wsrep_on is enabled
       // to allow changes to them to replicate with Galera
       printf("\\d |\n"
@@ -2746,7 +2741,13 @@ main(int argc, char **argv)
         "ALTER TABLE time_zone_transition_type ENGINE=InnoDB;\n"
         "END IF|\n"
         "\\d ;\n");
-    }
+  }
+
+  if (argc == 1 && !opt_leap)
+  {
+    /* Argument is timezonedir */
+
+    root_name_end= strmake_buf(fullname, argv[0]);
 
     printf("TRUNCATE TABLE time_zone;\n");
     printf("TRUNCATE TABLE time_zone_name;\n");