MDEV-33442 REPAIR TABLE corrupts UUIDs

Problem:
REPAIR TABLE executed for a pre-MDEV-29959 table (with the old UUID format)
updated the server version in the FRM file without rewriting the data,
so it created a new FRM for old UUIDs. After that MariaDB could not
read UUIDs correctly.

Fix:

- Adding a new virtual method in class Type_handler:

      virtual bool type_handler_for_implicit_upgrade() const;

  * For the up-to-date data types it returns "this".
  * For the data types which need to be implicitly upgraded
    during REPAIR TABLE or ALTER TABLE, it returns a pointer
    to a new replacement data type handler.

    Old VARCHAR and old UUID type handlers override this method.
    See more comments below.

- Changing the semantics of the method

    Type_handler::Column_definition_implicit_upgrade(Column_definition *c)

  to the opposite, so now:
    * c->type_handler() references the old data type (to upgrade from)
    * "this" references the new data type (to upgrade to).

  Before this change Column_definition_implicit_upgrade() was supposed
  to be called with the old data type handler (to upgrade from).

  Renaming the method to Column_definition_implicit_upgrade_to_this(),
  to avoid automatic merges in this method.

  Reflecting this change in Create_field::upgrade_data_types().

- Replacing the hard-coded data type tests inside handler::check_old_types()
  to a call for the new virtual method
  Type_handler::type_handler_for_implicit_upgrade()

- Overriding Type_handler_fbt::type_handler_for_implicit_upgrade()
  to call a new method FbtImpl::type_handler_for_implicit_upgrade().

  Reasoning:

  Type_handler_fbt is a template, so it has access only to "this".
  So in case of UUID data types, the type handler for old UUID
  knows nothing about the type handler of new UUID inside sql_type_fixedbin.h.
  So let's have Type_handler_fbt delegate type_handler_for_implicit_upgrade()
  to its Type_collection, which knows both new UUID and old UUID.

- Adding Type_collection_uuid::type_handler_for_implicit_upgrade().
  It returns a pointer to the new UUID type handler.

- Overriding Type_handler_var_string::type_handler_for_implicit_upgrade()
  to return a pointer to type_handler_varchar (true VARCHAR).

- Cleanup: these two methods:
    handler::check_old_types()
    handler::ha_check_for_upgrade()
  were always called consequently.
  So moving the call for check_old_types() inside ha_check_for_upgrade(),
  and making check_old_types() private.

- Cleanup: removing the "bool varchar" parameter from fill_alter_inplace_info(),
  as its not used any more.

mysql-test/main/type_decimal.result

@@ -1323,3 +1323,176 @@ SET sql_mode=DEFAULT;
 #
 # End of 10.4 tests
 #
+#
+# Start of 10.11 tests
+#
+#
+# MDEV-33442 REPAIR TABLE corrupts UUIDs
+#
+CREATE PROCEDURE show_table()
+BEGIN
+SHOW CREATE TABLE t1;
+SELECT VERSION FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME='t1' AND TABLE_SCHEMA='test';
+SELECT * FROM t1 ORDER BY a;
+END;
+$$
+# Upgrade using REPAIR
+CALL show_table;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(10,2)/*old*/ DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+VERSION
+9
+a
+123.45
+123.46
+123.47
+CHECK TABLE t1 FOR UPGRADE;
+Table	Op	Msg_type	Msg_text
+test.t1	check	error	Upgrade required. Please do "REPAIR TABLE `t1`" or dump/reload to fix it!
+CALL show_table;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(10,2)/*old*/ DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+VERSION
+9
+a
+123.45
+123.46
+123.47
+CHECK TABLE t1 FOR UPGRADE;
+Table	Op	Msg_type	Msg_text
+test.t1	check	error	Upgrade required. Please do "REPAIR TABLE `t1`" or dump/reload to fix it!
+CALL show_table;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(10,2)/*old*/ DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+VERSION
+9
+a
+123.45
+123.46
+123.47
+REPAIR TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	repair	status	OK
+# Expect old decimal, as it does not implicitly upgrade to new decimal
+CALL show_table;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(10,2)/*old*/ DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+VERSION
+10
+a
+123.45
+123.46
+123.47
+CHECK TABLE t1 FOR UPGRADE;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+CALL show_table;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(10,2)/*old*/ DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+VERSION
+10
+a
+123.45
+123.46
+123.47
+DROP TABLE t1;
+# Upgrade using ALTER, adding a table COMMENT
+# Upgrade a 10.11.4 table using ALTER, adding a table COMMENT
+CALL show_table;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(10,2)/*old*/ DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+VERSION
+9
+a
+123.45
+123.46
+123.47
+# ALTER..INPLACE should fail - the FRM file is too old and needs upgrade
+ALTER IGNORE TABLE t1 ALGORITHM=INPLACE, COMMENT 'test10';
+ERROR 0A000: ALGORITHM=INPLACE is not supported for this operation. Try ALGORITHM=COPY
+ALTER IGNORE TABLE t1 COMMENT 'test11';
+# Expect old decimal, as it does not implicitly upgrade to new decimal
+CALL show_table;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(10,2)/*old*/ DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci COMMENT='test11'
+VERSION
+10
+a
+123.45
+123.46
+123.47
+# Now ALTER..INPLACE should work
+ALTER IGNORE TABLE t1 ALGORITHM=INPLACE, COMMENT 'test12';
+CALL show_table;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(10,2)/*old*/ DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci COMMENT='test12'
+VERSION
+10
+a
+123.45
+123.46
+123.47
+DROP TABLE t1;
+# Upgrade using ALTER, adding a column DEFAULT
+# Upgrade a 10.11.4 table using ALTER, adding a table COMMENT
+CALL show_table;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(10,2)/*old*/ DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+VERSION
+9
+a
+123.45
+123.46
+123.47
+# ALTER..INPLACE should fail - the FRM file is too old and needs upgrade
+ALTER IGNORE TABLE t1 ALGORITHM=INPLACE, MODIFY a DECIMAL(10,2) DEFAULT 10;
+ERROR 0A000: ALGORITHM=INPLACE is not supported for this operation. Try ALGORITHM=COPY
+ALTER IGNORE TABLE t1 MODIFY a DECIMAL(10,2) DEFAULT 11;
+# Expect new decimal, as we explicitly redefined the data type
+CALL show_table;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(10,2) DEFAULT 11.00
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+VERSION
+10
+a
+123.45
+123.46
+123.47
+# Now ALTER..INPLACE should work
+ALTER IGNORE TABLE t1 ALGORITHM=INPLACE, MODIFY a DECIMAL(10,2) DEFAULT 12;
+CALL show_table;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` decimal(10,2) DEFAULT 12.00
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+VERSION
+10
+a
+123.45
+123.46
+123.47
+DROP TABLE t1;
+DROP PROCEDURE show_table;
+#
+# End of 10.11 tests
+#

mysql-test/main/type_decimal.test

@@ -826,3 +826,93 @@ SET sql_mode=DEFAULT;
 --echo #
 --echo # End of 10.4 tests
 --echo #
+
+--echo #
+--echo # Start of 10.11 tests
+--echo #
+
+--echo #
+--echo # MDEV-33442 REPAIR TABLE corrupts UUIDs
+--echo #
+
+DELIMITER $$;
+CREATE PROCEDURE show_table()
+BEGIN
+  SHOW CREATE TABLE t1;
+  SELECT VERSION FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME='t1' AND TABLE_SCHEMA='test';
+  SELECT * FROM t1 ORDER BY a;
+END;
+$$
+DELIMITER ;$$
+
+--echo # Upgrade using REPAIR
+
+--copy_file std_data/old_decimal/t1dec102.frm $MYSQLD_DATADIR/test/t1.frm
+--copy_file std_data/old_decimal/t1dec102.MYD $MYSQLD_DATADIR/test/t1.MYD
+--copy_file std_data/old_decimal/t1dec102.MYI $MYSQLD_DATADIR/test/t1.MYI
+CALL show_table;
+
+CHECK TABLE t1 FOR UPGRADE;
+CALL show_table;
+
+CHECK TABLE t1 FOR UPGRADE;
+CALL show_table;
+
+REPAIR TABLE t1;
+--echo # Expect old decimal, as it does not implicitly upgrade to new decimal
+CALL show_table;
+
+CHECK TABLE t1 FOR UPGRADE;
+CALL show_table;
+DROP TABLE t1;
+
+
+--echo # Upgrade using ALTER, adding a table COMMENT
+
+--echo # Upgrade a 10.11.4 table using ALTER, adding a table COMMENT
+--copy_file std_data/old_decimal/t1dec102.frm $MYSQLD_DATADIR/test/t1.frm
+--copy_file std_data/old_decimal/t1dec102.MYD $MYSQLD_DATADIR/test/t1.MYD
+--copy_file std_data/old_decimal/t1dec102.MYI $MYSQLD_DATADIR/test/t1.MYI
+CALL show_table;
+
+--echo # ALTER..INPLACE should fail - the FRM file is too old and needs upgrade
+--error ER_ALTER_OPERATION_NOT_SUPPORTED
+ALTER IGNORE TABLE t1 ALGORITHM=INPLACE, COMMENT 'test10';
+ALTER IGNORE TABLE t1 COMMENT 'test11';
+-- echo # Expect old decimal, as it does not implicitly upgrade to new decimal
+CALL show_table;
+
+--echo # Now ALTER..INPLACE should work
+ALTER IGNORE TABLE t1 ALGORITHM=INPLACE, COMMENT 'test12';
+CALL show_table;
+
+DROP TABLE t1;
+
+
+--echo # Upgrade using ALTER, adding a column DEFAULT
+
+--echo # Upgrade a 10.11.4 table using ALTER, adding a table COMMENT
+--copy_file std_data/old_decimal/t1dec102.frm $MYSQLD_DATADIR/test/t1.frm
+--copy_file std_data/old_decimal/t1dec102.MYD $MYSQLD_DATADIR/test/t1.MYD
+--copy_file std_data/old_decimal/t1dec102.MYI $MYSQLD_DATADIR/test/t1.MYI
+CALL show_table;
+
+--echo # ALTER..INPLACE should fail - the FRM file is too old and needs upgrade
+--error ER_ALTER_OPERATION_NOT_SUPPORTED
+ALTER IGNORE TABLE t1 ALGORITHM=INPLACE, MODIFY a DECIMAL(10,2) DEFAULT 10;
+ALTER IGNORE TABLE t1 MODIFY a DECIMAL(10,2) DEFAULT 11;
+--echo # Expect new decimal, as we explicitly redefined the data type
+CALL show_table;
+
+--echo # Now ALTER..INPLACE should work
+ALTER IGNORE TABLE t1 ALGORITHM=INPLACE, MODIFY a DECIMAL(10,2) DEFAULT 12;
+CALL show_table;
+
+DROP TABLE t1;
+
+DROP PROCEDURE show_table;
+
+
+--echo #
+--echo # End of 10.11 tests
+--echo #