MDEV-16542 Fix ALTER TABLE FORCE to upgrade temporal types

mysql-test/main/type_temporal_mysql56_debug.test

+--echo #
+--echo # Start of 10.4 tests
+--echo #
+
+--echo #
+--echo #  MDEV-16542 Fix ALTER TABLE FORCE to upgrade temporal types
+--echo #
+
+DELIMITER $$;
+CREATE PROCEDURE mdev16542_create_select()
+BEGIN
+  SELECT '# CREATE..SELECT and SHOW' AS ``;
+  CREATE TABLE t2 AS SELECT
+    a0, a1, a2, a3, a4, a5, a6,
+    COALESCE(a0),
+    COALESCE(a1),
+    COALESCE(a2),
+    COALESCE(a3),
+    COALESCE(a4),
+    COALESCE(a5),
+    COALESCE(a6)
+  FROM t1;
+  SHOW CREATE TABLE t2;
+  DROP TABLE t2;
+END;
+$$
+
+CREATE PROCEDURE mdev16542_alter_force_and_show()
+BEGIN
+  SELECT '# ALTER..FORCE and SHOW' AS ``;
+  ALTER TABLE t1 FORCE;
+  SHOW CREATE TABLE t1;
+END;
+$$
+
+CREATE PROCEDURE mdev16542()
+BEGIN
+  SET SESSION debug_dbug="+d,sql_type";
+  SELECT '# Original table' AS ``;
+  SHOW CREATE TABLE t1;
+  CALL mdev16542_create_select();
+  CALL mdev16542_alter_force_and_show();
+
+  SELECT '# Setting @@global.mysql56_temporal_format=false' AS ``;
+  SET @@global.mysql56_temporal_format=false;
+  CALL mdev16542_create_select();
+  CALL mdev16542_alter_force_and_show();
+
+  SELECT '# Setting @@global.mysql56_temporal_format=true' AS ``;
+  SET @@global.mysql56_temporal_format=true;
+  CALL mdev16542_create_select();
+  CALL mdev16542_alter_force_and_show();
+  SET SESSION debug_dbug="-d,sql_type";
+END;
+$$
+DELIMITER ;$$
+
+SET @@global.mysql56_temporal_format=true;
+
+CREATE TABLE t1 (
+  a0 TIME,
+  a1 TIME(1),
+  a2 TIME(2),
+  a3 TIME(3),
+  a4 TIME(4),
+  a5 TIME(5),
+  a6 TIME(6)
+);
+CALL mdev16542;
+DROP TABLE t1;
+
+
+CREATE TABLE t1 (
+  a0 DATETIME,
+  a1 DATETIME(1),
+  a2 DATETIME(2),
+  a3 DATETIME(3),
+  a4 DATETIME(4),
+  a5 DATETIME(5),
+  a6 DATETIME(6)
+);
+CALL mdev16542;
+DROP TABLE t1;
+
+
+CREATE TABLE t1 (
+  a0 TIMESTAMP,
+  a1 TIMESTAMP(1),
+  a2 TIMESTAMP(2),
+  a3 TIMESTAMP(3),
+  a4 TIMESTAMP(4),
+  a5 TIMESTAMP(5),
+  a6 TIMESTAMP(6)
+);
+CALL mdev16542;
+DROP TABLE t1;
+
+SET @@global.mysql56_temporal_format=DEFAULT;
+DROP PROCEDURE mdev16542;
+DROP PROCEDURE mdev16542_create_select;
+DROP PROCEDURE mdev16542_alter_force_and_show;
+
+--echo #
+--echo # End of 10.4 tests
+--echo #

sql/field.cc

@@ -10709,11 +10709,6 @@ Column_definition::Column_definition(THD *thd, Field *old_field,
     key_length/= charset->mbmaxlen;
     break;
   case MYSQL_TYPE_STRING:
-    /* Change CHAR -> VARCHAR if dynamic record length */
-    if (old_field->type() == MYSQL_TYPE_VAR_STRING)
-      set_handler(&type_handler_varchar);
-    /* fall through */
-
   case MYSQL_TYPE_ENUM:
   case MYSQL_TYPE_SET:
   case MYSQL_TYPE_VARCHAR:
@@ -10761,6 +10756,8 @@ Column_definition::Column_definition(THD *thd, Field *old_field,
 
   char_length= (uint)length;
 
+  type_handler()->Column_definition_implicit_upgrade(this);
+
   /*
     Copy the default (constant/function) from the column object orig_field, if
     supplied. We do this if all these conditions are met:

sql/sql_show.cc

@@ -2184,6 +2184,12 @@ int show_create_table(THD *thd, TABLE_LIST *table_list, String *packet,
     field->sql_type(type);
     packet->append(type.ptr(), type.length(), system_charset_info);
 
+    DBUG_EXECUTE_IF("sql_type",
+                    packet->append(" /* ");
+                    packet->append(field->type_handler()->version().ptr());
+                    packet->append(" */ ");
+                    );
+
     if (field->has_charset() && !(sql_mode & (MODE_MYSQL323 | MODE_MYSQL40)))
     {
       if (field->charset() != share->table_charset)

sql/sql_type.cc

@@ -472,6 +472,11 @@ const Name
   Type_handler_datetime_common::m_name_datetime(STRING_WITH_LEN("datetime")),
   Type_handler_timestamp_common::m_name_timestamp(STRING_WITH_LEN("timestamp"));
 
+const Name
+  Type_handler::m_version_default(STRING_WITH_LEN("")),
+  Type_handler::m_version_mariadb53(STRING_WITH_LEN("mariadb-5.3")),
+  Type_handler::m_version_mysql56(STRING_WITH_LEN("mysql-5.6"));
+
 
 const Type_limits_int
   Type_handler_tiny::m_limits_sint8=      Type_limits_sint8(),
@@ -6532,3 +6537,40 @@ bool Type_handler_decimal_result::Item_eq_value(THD *thd,
 }
 
 /***************************************************************************/
+
+void Type_handler_var_string::
+  Column_definition_implicit_upgrade(Column_definition *c) const
+{
+  // Change old VARCHAR to new VARCHAR
+  c->set_handler(&type_handler_varchar);
+}
+
+
+void Type_handler_time_common::
+  Column_definition_implicit_upgrade(Column_definition *c) const
+{
+  if (opt_mysql56_temporal_format)
+    c->set_handler(&type_handler_time2);
+  else
+    c->set_handler(&type_handler_time);
+}
+
+
+void Type_handler_datetime_common::
+  Column_definition_implicit_upgrade(Column_definition *c) const
+{
+  if (opt_mysql56_temporal_format)
+    c->set_handler(&type_handler_datetime2);
+  else
+    c->set_handler(&type_handler_datetime);
+}
+
+
+void Type_handler_timestamp_common::
+  Column_definition_implicit_upgrade(Column_definition *c) const
+{
+  if (opt_mysql56_temporal_format)
+    c->set_handler(&type_handler_timestamp2);
+  else
+    c->set_handler(&type_handler_timestamp);
+}

sql/sql_type.h

@@ -1031,6 +1031,9 @@ class Information_schema_character_attributes
 class Type_handler
 {
 protected:
+  static const Name m_version_default;
+  static const Name m_version_mysql56;
+  static const Name m_version_mariadb53;
   String *print_item_value_csstr(THD *thd, Item *item, String *str) const;
   String *print_item_value_temporal(THD *thd, Item *item, String *str,
                                      const Name &type_name, String *buf) const;
@@ -1096,6 +1099,7 @@ class Type_handler
                                                  const Type_handler *h2);
 
   virtual const Name name() const= 0;
+  virtual const Name version() const { return m_version_default; }
   virtual enum_field_types field_type() const= 0;
   virtual enum_field_types real_field_type() const { return field_type(); }
   /**
@@ -1253,6 +1257,9 @@ class Type_handler
   virtual Field *make_conversion_table_field(TABLE *TABLE,
                                              uint metadata,
                                              const Field *target) const= 0;
+  // Automatic upgrade, e.g. for ALTER TABLE t1 FORCE
+  virtual void Column_definition_implicit_upgrade(Column_definition *c) const
+  { }
   virtual bool Column_definition_fix_attributes(Column_definition *c) const= 0;
   virtual bool Column_definition_prepare_stage1(THD *thd,
                                                 MEM_ROOT *mem_root,
@@ -2878,6 +2885,7 @@ class Type_handler_time_common: public Type_handler_temporal_result
     return Item_divisor_precision_increment_with_seconds(item);
   }
   const Type_handler *type_handler_for_comparison() const;
+  void Column_definition_implicit_upgrade(Column_definition *c) const;
   bool Column_definition_fix_attributes(Column_definition *c) const;
   bool Item_save_in_value(Item *item, st_value *value) const;
   bool Item_send(Item *item, Protocol *protocol, st_value *buf) const
@@ -2923,6 +2931,7 @@ class Type_handler_time: public Type_handler_time_common
 public:
   static uint hires_bytes(uint dec) { return m_hires_bytes[dec]; }
   virtual ~Type_handler_time() {}
+  const Name version() const { return m_version_mariadb53; }
   uint32 calc_pack_length(uint32 length) const;
   Field *make_conversion_table_field(TABLE *, uint metadata,
                                      const Field *target) const;
@@ -2948,6 +2957,7 @@ class Type_handler_time2: public Type_handler_time_common
 {
 public:
   virtual ~Type_handler_time2() {}
+  const Name version() const { return m_version_mysql56; }
   enum_field_types real_field_type() const { return MYSQL_TYPE_TIME2; }
   uint32 calc_pack_length(uint32 length) const;
   Field *make_conversion_table_field(TABLE *, uint metadata,
@@ -3082,6 +3092,7 @@ class Type_handler_datetime_common: public Type_handler_temporal_with_date
   }
   Item *create_typecast_item(THD *thd, Item *item,
                              const Type_cast_attributes &attr) const;
+  void Column_definition_implicit_upgrade(Column_definition *c) const;
   bool Column_definition_fix_attributes(Column_definition *c) const;
   uint Item_decimal_scale(const Item *item) const
   {
@@ -3115,6 +3126,7 @@ class Type_handler_datetime: public Type_handler_datetime_common
 public:
   static uint hires_bytes(uint dec) { return m_hires_bytes[dec]; }
   virtual ~Type_handler_datetime() {}
+  const Name version() const { return m_version_mariadb53; }
   uint32 calc_pack_length(uint32 length) const;
   Field *make_conversion_table_field(TABLE *, uint metadata,
                                      const Field *target) const;
@@ -3140,6 +3152,7 @@ class Type_handler_datetime2: public Type_handler_datetime_common
 {
 public:
   virtual ~Type_handler_datetime2() {}
+  const Name version() const { return m_version_mysql56; }
   enum_field_types real_field_type() const { return MYSQL_TYPE_DATETIME2; }
   uint32 calc_pack_length(uint32 length) const;
   Field *make_conversion_table_field(TABLE *, uint metadata,
@@ -3178,6 +3191,7 @@ class Type_handler_timestamp_common: public Type_handler_temporal_with_date
   {
     return true;
   }
+  void Column_definition_implicit_upgrade(Column_definition *c) const;
   bool Column_definition_fix_attributes(Column_definition *c) const;
   uint Item_decimal_scale(const Item *item) const
   {
@@ -3211,6 +3225,7 @@ class Type_handler_timestamp: public Type_handler_timestamp_common
 public:
   static uint sec_part_bytes(uint dec) { return m_sec_part_bytes[dec]; }
   virtual ~Type_handler_timestamp() {}
+  const Name version() const { return m_version_mariadb53; }
   uint32 calc_pack_length(uint32 length) const;
   Field *make_conversion_table_field(TABLE *, uint metadata,
                                      const Field *target) const;
@@ -3236,6 +3251,7 @@ class Type_handler_timestamp2: public Type_handler_timestamp_common
 {
 public:
   virtual ~Type_handler_timestamp2() {}
+  const Name version() const { return m_version_mysql56; }
   enum_field_types real_field_type() const { return MYSQL_TYPE_TIMESTAMP2; }
   uint32 calc_pack_length(uint32 length) const;
   Field *make_conversion_table_field(TABLE *, uint metadata,
@@ -3436,6 +3452,7 @@ class Type_handler_var_string: public Type_handler_string
   {
     return varstring_type_handler(item);
   }
+  void Column_definition_implicit_upgrade(Column_definition *c) const;
   bool Column_definition_fix_attributes(Column_definition *c) const;
   bool Column_definition_prepare_stage2(Column_definition *c,
                                         handler *file,