MDEV-5248 Serious incompatibility and data corruption of DATETIME and DATE types due to get_innobase_type_from_mysql_type refactor combined with InnoDB Online DDL

restore old innodb get_innobase_type_from_mysql_type() function,
record all mysql_type->innodb_type mapping
(as generated by mysql-5.6).
add safety code to disable online alter when internal types don't match

storage/innobase/dict/dict0stats.cc:
  revert to 5.6 state

8 files changed, 374 insertions, 98 deletions

diff --git a/mysql-test/suite/innodb/r/1byte_data_int.result b/mysql-test/suite/innodb/r/1byte_data_int.result
deleted file mode 100644
index 28cb85afcd8..00000000000
--- a/mysql-test/suite/innodb/r/1byte_data_int.result
+++ /dev/null
@@ -1,23 +0,0 @@
-# Create a table with a 1-byte ENUM, 1-byte SET, and TINYINT UNSIGNED.
-CREATE TABLE t1
-(
-t1_enum       ENUM("a", "b", "c"),
-t1_set        SET("a", "b", "c"),
-t1_tinyint_s  TINYINT,
-t1_tinyint_u  TINYINT UNSIGNED
-) ENGINE=InnoDB;
-# All t1 fields' mtypes should be 6 (DATA_INT).
-SELECT
-name,
-mtype,
-(prtype & 512) = 512 AS is_unsigned
-FROM information_schema.INNODB_SYS_COLUMNS
-WHERE name LIKE "t1\_%"
-ORDER BY name;
-name	mtype	is_unsigned
-t1_enum	6	1
-t1_set	6	1
-t1_tinyint_s	6	0
-t1_tinyint_u	6	1
-# Cleanup
-DROP TABLE t1;
diff --git a/mysql-test/suite/innodb/r/data_types.result b/mysql-test/suite/innodb/r/data_types.result
new file mode 100644
index 00000000000..c026d44eb79
--- /dev/null
+++ b/mysql-test/suite/innodb/r/data_types.result
@@ -0,0 +1,155 @@
+CREATE TABLE t1
+(
+t1_BIGINT BIGINT,
+t1_BIGINT_UNSIGNED BIGINT UNSIGNED,
+t1_BINARY_100 BINARY(100),
+t1_BIT_2 BIT(2),
+t1_BIT_20 BIT(20),
+t1_BLOB BLOB,
+t1_CHAR_100 CHAR(100),
+t1_CHAR_100_BINARY CHAR(100) BINARY,
+t1_DATE DATE,
+t1_DATETIME DATETIME,
+t1_DATETIME_6 DATETIME(6),
+t1_DECIMAL_10_3 DECIMAL(10,3),
+t1_DECIMAL_10_3_UNSIGNED DECIMAL(10,3) UNSIGNED,
+t1_DOUBLE DOUBLE,
+t1_DOUBLE_UNSIGNED DOUBLE UNSIGNED,
+t1_ENUM       ENUM('a', 'b', 'c'),
+t1_ENUM_BINARY ENUM('a','b') BINARY,
+t1_ENUM_256    ENUM('a1', 'a2', 'a3', 'a4', 'a5', 'a6', 'a7', 'a8', 'a9',
+'a10', 'a11', 'a12', 'a13', 'a14', 'a15', 'a16', 'a17', 'a18', 'a19',
+'a20', 'a21', 'a22', 'a23', 'a24', 'a25', 'a26', 'a27', 'a28', 'a29',
+'a30', 'a31', 'a32', 'a33', 'a34', 'a35', 'a36', 'a37', 'a38', 'a39',
+'a40', 'a41', 'a42', 'a43', 'a44', 'a45', 'a46', 'a47', 'a48', 'a49',
+'a50', 'a51', 'a52', 'a53', 'a54', 'a55', 'a56', 'a57', 'a58', 'a59',
+'a60', 'a61', 'a62', 'a63', 'a64', 'a65', 'a66', 'a67', 'a68', 'a69',
+'a70', 'a71', 'a72', 'a73', 'a74', 'a75', 'a76', 'a77', 'a78', 'a79',
+'a80', 'a81', 'a82', 'a83', 'a84', 'a85', 'a86', 'a87', 'a88', 'a89',
+'a90', 'a91', 'a92', 'a93', 'a94', 'a95', 'a96', 'a97', 'a98', 'a99',
+'a100', 'a101', 'a102', 'a103', 'a104', 'a105', 'a106', 'a107', 'a108',
+'a109', 'a110', 'a111', 'a112', 'a113', 'a114', 'a115', 'a116', 'a117',
+'a118', 'a119', 'a120', 'a121', 'a122', 'a123', 'a124', 'a125', 'a126',
+'a127', 'a128', 'a129', 'a130', 'a131', 'a132', 'a133', 'a134', 'a135',
+'a136', 'a137', 'a138', 'a139', 'a140', 'a141', 'a142', 'a143', 'a144',
+'a145', 'a146', 'a147', 'a148', 'a149', 'a150', 'a151', 'a152', 'a153',
+'a154', 'a155', 'a156', 'a157', 'a158', 'a159', 'a160', 'a161', 'a162',
+'a163', 'a164', 'a165', 'a166', 'a167', 'a168', 'a169', 'a170', 'a171',
+'a172', 'a173', 'a174', 'a175', 'a176', 'a177', 'a178', 'a179', 'a180',
+'a181', 'a182', 'a183', 'a184', 'a185', 'a186', 'a187', 'a188', 'a189',
+'a190', 'a191', 'a192', 'a193', 'a194', 'a195', 'a196', 'a197', 'a198',
+'a199', 'a200', 'a201', 'a202', 'a203', 'a204', 'a205', 'a206', 'a207',
+'a208', 'a209', 'a210', 'a211', 'a212', 'a213', 'a214', 'a215', 'a216',
+'a217', 'a218', 'a219', 'a220', 'a221', 'a222', 'a223', 'a224', 'a225',
+'a226', 'a227', 'a228', 'a229', 'a230', 'a231', 'a232', 'a233', 'a234',
+'a235', 'a236', 'a237', 'a238', 'a239', 'a240', 'a241', 'a242', 'a243',
+'a244', 'a245', 'a246', 'a247', 'a248', 'a249', 'a250', 'a251', 'a252',
+'a253', 'a254', 'a255', 'a256'), 
+t1_FLOAT FLOAT,
+t1_FLOAT_UNSIGNED FLOAT UNSIGNED,
+t1_INT INT,
+t1_INT_UNSIGNED INT UNSIGNED,
+t1_LONGBLOB LONGBLOB,
+t1_LONGTEXT LONGTEXT,
+t1_MEDIUMBLOB MEDIUMBLOB,
+t1_MEDIUMINT MEDIUMINT,
+t1_MEDIUMINT_UNSIGNED MEDIUMINT UNSIGNED,
+t1_MEDIUMTEXT MEDIUMTEXT,
+t1_SET        SET('a', 'b', 'c'),
+t1_SET_BINARY SET('a','b') BINARY,
+t1_SET_9      SET('a1', 'a2', 'a3', 'a4', 'a5', 'a6', 'a7', 'a8', 'a9'),
+t1_SMALLINT SMALLINT,
+t1_SMALLINT_UNSIGNED SMALLINT UNSIGNED,
+t1_TEXT TEXT,
+t1_TIME TIME,
+t1_TIME_4 TIME(4),
+t1_TIMESTAMP TIMESTAMP,
+t1_TIMESTAMP_5 TIMESTAMP(5),
+t1_TINYBLOB TINYBLOB,
+t1_TINYINT  TINYINT,
+t1_TINYINT_UNSIGNED TINYINT UNSIGNED,
+t1_TINYTEXT TINYTEXT,
+t1_VARBINARY_100 VARBINARY(100),
+t1_VARCHAR_10 VARCHAR(10),
+t1_VARCHAR_10_BINARY VARCHAR(10) BINARY,
+t1_VARCHAR_500 VARCHAR(500),
+t1_VARCHAR_500_BINARY VARCHAR(500) BINARY,
+t1_YEAR_2 YEAR(2),
+t1_YEAR_4 YEAR(4)
+) ENGINE=InnoDB;
+Warnings:
+Note	1287	'YEAR(2)' is deprecated and will be removed in a future release. Please use YEAR(4) instead
+SELECT
+name,
+CASE mtype
+WHEN 1 THEN "DATA_VARCHAR"
+    WHEN 2 THEN "DATA_CHAR"
+    WHEN 3 THEN "DATA_FIXBINARY"
+    WHEN 4 THEN "DATA_BINARY"
+    WHEN 5 THEN "DATA_BLOB"
+    WHEN 6 THEN "DATA_INT"
+    WHEN 7 THEN "DATA_SYS_CHILD"
+    WHEN 8 THEN "DATA_SYS"
+    WHEN 9 THEN "DATA_FLOAT"
+    WHEN 10 THEN "DATA_DOUBLE"
+    WHEN 11 THEN "DATA_DECIMAL"
+    WHEN 12 THEN "DATA_VARMYSQL"
+    WHEN 13 THEN "DATA_MYSQL"
+    WHEN 63 THEN "DATA_MTYPE_MAX"
+    ELSE mtype
+END AS mtype,
+IF((prtype & 512) = 512,"UNSIGNED","") AS is_unsigned
+FROM information_schema.INNODB_SYS_COLUMNS
+WHERE name LIKE "t1\_%"
+ORDER BY name;
+name	mtype	is_unsigned
+t1_BIGINT	DATA_INT	
+t1_BIGINT_UNSIGNED	DATA_INT	UNSIGNED
+t1_BINARY_100	DATA_FIXBINARY	
+t1_BIT_2	DATA_FIXBINARY	UNSIGNED
+t1_BIT_20	DATA_FIXBINARY	UNSIGNED
+t1_BLOB	DATA_BLOB	
+t1_CHAR_100	DATA_CHAR	
+t1_CHAR_100_BINARY	DATA_MYSQL	
+t1_DATE	DATA_INT	
+t1_DATETIME	DATA_INT	
+t1_DATETIME_6	DATA_FIXBINARY	
+t1_DECIMAL_10_3	DATA_FIXBINARY	
+t1_DECIMAL_10_3_UNSIGNED	DATA_FIXBINARY	UNSIGNED
+t1_DOUBLE	DATA_DOUBLE	
+t1_DOUBLE_UNSIGNED	DATA_DOUBLE	UNSIGNED
+t1_ENUM	DATA_INT	UNSIGNED
+t1_ENUM_256	DATA_INT	UNSIGNED
+t1_ENUM_BINARY	DATA_INT	UNSIGNED
+t1_FLOAT	DATA_FLOAT	
+t1_FLOAT_UNSIGNED	DATA_FLOAT	UNSIGNED
+t1_INT	DATA_INT	
+t1_INT_UNSIGNED	DATA_INT	UNSIGNED
+t1_LONGBLOB	DATA_BLOB	
+t1_LONGTEXT	DATA_BLOB	
+t1_MEDIUMBLOB	DATA_BLOB	
+t1_MEDIUMINT	DATA_INT	
+t1_MEDIUMINT_UNSIGNED	DATA_INT	UNSIGNED
+t1_MEDIUMTEXT	DATA_BLOB	
+t1_SET	DATA_INT	UNSIGNED
+t1_SET_9	DATA_INT	UNSIGNED
+t1_SET_BINARY	DATA_INT	UNSIGNED
+t1_SMALLINT	DATA_INT	
+t1_SMALLINT_UNSIGNED	DATA_INT	UNSIGNED
+t1_TEXT	DATA_BLOB	
+t1_TIME	DATA_INT	
+t1_TIMESTAMP	DATA_INT	UNSIGNED
+t1_TIMESTAMP_5	DATA_FIXBINARY	UNSIGNED
+t1_TIME_4	DATA_FIXBINARY	
+t1_TINYBLOB	DATA_BLOB	
+t1_TINYINT	DATA_INT	
+t1_TINYINT_UNSIGNED	DATA_INT	UNSIGNED
+t1_TINYTEXT	DATA_BLOB	
+t1_VARBINARY_100	DATA_BINARY	
+t1_VARCHAR_10	DATA_VARCHAR	
+t1_VARCHAR_10_BINARY	DATA_VARMYSQL	
+t1_VARCHAR_500	DATA_VARCHAR	
+t1_VARCHAR_500_BINARY	DATA_VARMYSQL	
+t1_YEAR_2	DATA_INT	UNSIGNED
+t1_YEAR_4	DATA_INT	UNSIGNED
+DROP TABLE t1;
diff --git a/mysql-test/suite/innodb/t/1byte_data_int.test b/mysql-test/suite/innodb/t/1byte_data_int.test
deleted file mode 100644
index 26ca8a53283..00000000000
--- a/mysql-test/suite/innodb/t/1byte_data_int.test
+++ /dev/null
@@ -1,25 +0,0 @@
---source include/have_innodb.inc
-
---echo # Create a table with a 1-byte ENUM, 1-byte SET, and TINYINT UNSIGNED.
-
-CREATE TABLE t1
-(
-  t1_enum       ENUM("a", "b", "c"),
-  t1_set        SET("a", "b", "c"),
-  t1_tinyint_s  TINYINT,
-  t1_tinyint_u  TINYINT UNSIGNED
-) ENGINE=InnoDB;
-
---echo # All t1 fields' mtypes should be 6 (DATA_INT).
-
-SELECT
-  name,
-  mtype,
-  (prtype & 512) = 512 AS is_unsigned
-FROM information_schema.INNODB_SYS_COLUMNS
-WHERE name LIKE "t1\_%"
-ORDER BY name;
-
---echo # Cleanup
-
-DROP TABLE t1;
diff --git a/mysql-test/suite/innodb/t/1byte_data_int.opt b/mysql-test/suite/innodb/t/data_types.opt
index 3ad568c816e..3ad568c816e 100644
--- a/mysql-test/suite/innodb/t/1byte_data_int.opt
+++ b/mysql-test/suite/innodb/t/data_types.opt
diff --git a/mysql-test/suite/innodb/t/data_types.test b/mysql-test/suite/innodb/t/data_types.test
new file mode 100644
index 00000000000..0978146361c
--- /dev/null
+++ b/mysql-test/suite/innodb/t/data_types.test
@@ -0,0 +1,118 @@
+#
+# MDEV-5248 Serious incompatibility and data corruption of DATETIME and DATE types due to get_innobase_type_from_mysql_type refactor combined with InnoDB Online DDL
+#
+
+#
+# This test records what *internal type codes* innodb is using for every
+# MariaDB data type. THEY MUST ALWAYS BE THE SAME AND NEVER CHANGE!
+# Otherwise we create a compatibility problem and possible silent data
+# corruption too, see MDEV-5248
+#
+
+--source include/have_innodb.inc
+
+CREATE TABLE t1
+(
+  t1_BIGINT BIGINT,
+  t1_BIGINT_UNSIGNED BIGINT UNSIGNED,
+  t1_BINARY_100 BINARY(100),
+  t1_BIT_2 BIT(2),
+  t1_BIT_20 BIT(20),
+  t1_BLOB BLOB,
+  t1_CHAR_100 CHAR(100),
+  t1_CHAR_100_BINARY CHAR(100) BINARY,
+  t1_DATE DATE,
+  t1_DATETIME DATETIME,
+  t1_DATETIME_6 DATETIME(6),
+  t1_DECIMAL_10_3 DECIMAL(10,3),
+  t1_DECIMAL_10_3_UNSIGNED DECIMAL(10,3) UNSIGNED,
+  t1_DOUBLE DOUBLE,
+  t1_DOUBLE_UNSIGNED DOUBLE UNSIGNED,
+  t1_ENUM       ENUM('a', 'b', 'c'),
+  t1_ENUM_BINARY ENUM('a','b') BINARY,
+  t1_ENUM_256    ENUM('a1', 'a2', 'a3', 'a4', 'a5', 'a6', 'a7', 'a8', 'a9',
+    'a10', 'a11', 'a12', 'a13', 'a14', 'a15', 'a16', 'a17', 'a18', 'a19',
+    'a20', 'a21', 'a22', 'a23', 'a24', 'a25', 'a26', 'a27', 'a28', 'a29',
+    'a30', 'a31', 'a32', 'a33', 'a34', 'a35', 'a36', 'a37', 'a38', 'a39',
+    'a40', 'a41', 'a42', 'a43', 'a44', 'a45', 'a46', 'a47', 'a48', 'a49',
+    'a50', 'a51', 'a52', 'a53', 'a54', 'a55', 'a56', 'a57', 'a58', 'a59',
+    'a60', 'a61', 'a62', 'a63', 'a64', 'a65', 'a66', 'a67', 'a68', 'a69',
+    'a70', 'a71', 'a72', 'a73', 'a74', 'a75', 'a76', 'a77', 'a78', 'a79',
+    'a80', 'a81', 'a82', 'a83', 'a84', 'a85', 'a86', 'a87', 'a88', 'a89',
+    'a90', 'a91', 'a92', 'a93', 'a94', 'a95', 'a96', 'a97', 'a98', 'a99',
+    'a100', 'a101', 'a102', 'a103', 'a104', 'a105', 'a106', 'a107', 'a108',
+    'a109', 'a110', 'a111', 'a112', 'a113', 'a114', 'a115', 'a116', 'a117',
+    'a118', 'a119', 'a120', 'a121', 'a122', 'a123', 'a124', 'a125', 'a126',
+    'a127', 'a128', 'a129', 'a130', 'a131', 'a132', 'a133', 'a134', 'a135',
+    'a136', 'a137', 'a138', 'a139', 'a140', 'a141', 'a142', 'a143', 'a144',
+    'a145', 'a146', 'a147', 'a148', 'a149', 'a150', 'a151', 'a152', 'a153',
+    'a154', 'a155', 'a156', 'a157', 'a158', 'a159', 'a160', 'a161', 'a162',
+    'a163', 'a164', 'a165', 'a166', 'a167', 'a168', 'a169', 'a170', 'a171',
+    'a172', 'a173', 'a174', 'a175', 'a176', 'a177', 'a178', 'a179', 'a180',
+    'a181', 'a182', 'a183', 'a184', 'a185', 'a186', 'a187', 'a188', 'a189',
+    'a190', 'a191', 'a192', 'a193', 'a194', 'a195', 'a196', 'a197', 'a198',
+    'a199', 'a200', 'a201', 'a202', 'a203', 'a204', 'a205', 'a206', 'a207',
+    'a208', 'a209', 'a210', 'a211', 'a212', 'a213', 'a214', 'a215', 'a216',
+    'a217', 'a218', 'a219', 'a220', 'a221', 'a222', 'a223', 'a224', 'a225',
+    'a226', 'a227', 'a228', 'a229', 'a230', 'a231', 'a232', 'a233', 'a234',
+    'a235', 'a236', 'a237', 'a238', 'a239', 'a240', 'a241', 'a242', 'a243',
+    'a244', 'a245', 'a246', 'a247', 'a248', 'a249', 'a250', 'a251', 'a252',
+    'a253', 'a254', 'a255', 'a256'), 
+  t1_FLOAT FLOAT,
+  t1_FLOAT_UNSIGNED FLOAT UNSIGNED,
+  t1_INT INT,
+  t1_INT_UNSIGNED INT UNSIGNED,
+  t1_LONGBLOB LONGBLOB,
+  t1_LONGTEXT LONGTEXT,
+  t1_MEDIUMBLOB MEDIUMBLOB,
+  t1_MEDIUMINT MEDIUMINT,
+  t1_MEDIUMINT_UNSIGNED MEDIUMINT UNSIGNED,
+  t1_MEDIUMTEXT MEDIUMTEXT,
+  t1_SET        SET('a', 'b', 'c'),
+  t1_SET_BINARY SET('a','b') BINARY,
+  t1_SET_9      SET('a1', 'a2', 'a3', 'a4', 'a5', 'a6', 'a7', 'a8', 'a9'),
+  t1_SMALLINT SMALLINT,
+  t1_SMALLINT_UNSIGNED SMALLINT UNSIGNED,
+  t1_TEXT TEXT,
+  t1_TIME TIME,
+  t1_TIME_4 TIME(4),
+  t1_TIMESTAMP TIMESTAMP,
+  t1_TIMESTAMP_5 TIMESTAMP(5),
+  t1_TINYBLOB TINYBLOB,
+  t1_TINYINT  TINYINT,
+  t1_TINYINT_UNSIGNED TINYINT UNSIGNED,
+  t1_TINYTEXT TINYTEXT,
+  t1_VARBINARY_100 VARBINARY(100),
+  t1_VARCHAR_10 VARCHAR(10),
+  t1_VARCHAR_10_BINARY VARCHAR(10) BINARY,
+  t1_VARCHAR_500 VARCHAR(500),
+  t1_VARCHAR_500_BINARY VARCHAR(500) BINARY,
+  t1_YEAR_2 YEAR(2),
+  t1_YEAR_4 YEAR(4)
+) ENGINE=InnoDB;
+
+SELECT
+  name,
+  CASE mtype
+    WHEN 1 THEN "DATA_VARCHAR"
+    WHEN 2 THEN "DATA_CHAR"
+    WHEN 3 THEN "DATA_FIXBINARY"
+    WHEN 4 THEN "DATA_BINARY"
+    WHEN 5 THEN "DATA_BLOB"
+    WHEN 6 THEN "DATA_INT"
+    WHEN 7 THEN "DATA_SYS_CHILD"
+    WHEN 8 THEN "DATA_SYS"
+    WHEN 9 THEN "DATA_FLOAT"
+    WHEN 10 THEN "DATA_DOUBLE"
+    WHEN 11 THEN "DATA_DECIMAL"
+    WHEN 12 THEN "DATA_VARMYSQL"
+    WHEN 13 THEN "DATA_MYSQL"
+    WHEN 63 THEN "DATA_MTYPE_MAX"
+    ELSE mtype
+  END AS mtype,
+  IF((prtype & 512) = 512,"UNSIGNED","") AS is_unsigned
+FROM information_schema.INNODB_SYS_COLUMNS
+WHERE name LIKE "t1\_%"
+ORDER BY name;
+
+DROP TABLE t1;
diff --git a/storage/innobase/dict/dict0stats.cc b/storage/innobase/dict/dict0stats.cc
index ed10525b07d..25bcc87d93c 100644
--- a/storage/innobase/dict/dict0stats.cc
+++ b/storage/innobase/dict/dict0stats.cc
@@ -176,7 +176,7 @@ dict_stats_persistent_storage_check(
 			DATA_NOT_NULL, 192},
 
 		{"last_update", DATA_INT,
-			DATA_NOT_NULL | DATA_UNSIGNED, 4},
+			DATA_NOT_NULL, 4},
 
 		{"n_rows", DATA_INT,
 			DATA_NOT_NULL | DATA_UNSIGNED, 8},
@@ -207,7 +207,7 @@ dict_stats_persistent_storage_check(
 			DATA_NOT_NULL, 192},
 
 		{"last_update", DATA_INT,
-			DATA_NOT_NULL | DATA_UNSIGNED, 4},
+			DATA_NOT_NULL, 4},
 
 		{"stat_name", DATA_VARMYSQL,
 			DATA_NOT_NULL, 64*3},
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index 9b6c96078ac..82421d2d725 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -5745,67 +5745,92 @@ get_innobase_type_from_mysql_type(
 	8 bits: this is used in ibuf and also when DATA_NOT_NULL is ORed to
 	the type */
 
-	compile_time_assert((ulint)MYSQL_TYPE_STRING < 256);
-	compile_time_assert((ulint)MYSQL_TYPE_VAR_STRING < 256);
-	compile_time_assert((ulint)MYSQL_TYPE_DOUBLE < 256);
-	compile_time_assert((ulint)MYSQL_TYPE_FLOAT < 256);
-	compile_time_assert((ulint)MYSQL_TYPE_DECIMAL < 256);
+	DBUG_ASSERT((ulint)MYSQL_TYPE_STRING < 256);
+	DBUG_ASSERT((ulint)MYSQL_TYPE_VAR_STRING < 256);
+	DBUG_ASSERT((ulint)MYSQL_TYPE_DOUBLE < 256);
+	DBUG_ASSERT((ulint)MYSQL_TYPE_FLOAT < 256);
+	DBUG_ASSERT((ulint)MYSQL_TYPE_DECIMAL < 256);
 
-	*unsigned_flag = 0;
+	if (field->flags & UNSIGNED_FLAG) {
 
-	switch (field->key_type()) {
-	case HA_KEYTYPE_USHORT_INT:
-	case HA_KEYTYPE_ULONG_INT:
-	case HA_KEYTYPE_UINT24:
-	case HA_KEYTYPE_ULONGLONG:
 		*unsigned_flag = DATA_UNSIGNED;
-		/* fall through */
-	case HA_KEYTYPE_SHORT_INT:
-	case HA_KEYTYPE_LONG_INT:
-	case HA_KEYTYPE_INT24:
-	case HA_KEYTYPE_INT8:
-	case HA_KEYTYPE_LONGLONG:
+	} else {
+		*unsigned_flag = 0;
+	}
+
+	if (field->real_type() == MYSQL_TYPE_ENUM
+		|| field->real_type() == MYSQL_TYPE_SET) {
+
+		/* MySQL has field->type() a string type for these, but the
+		data is actually internally stored as an unsigned integer
+		code! */
+
+		*unsigned_flag = DATA_UNSIGNED; /* MySQL has its own unsigned
+						flag set to zero, even though
+						internally this is an unsigned
+						integer type */
 		return(DATA_INT);
-	case HA_KEYTYPE_FLOAT:
-		return(DATA_FLOAT);
-	case HA_KEYTYPE_DOUBLE:
-		return(DATA_DOUBLE);
-	case HA_KEYTYPE_BINARY:
-                if (field->type() == MYSQL_TYPE_TINY ||
-                    field->real_type() == MYSQL_TYPE_ENUM ||
-                    field->real_type() == MYSQL_TYPE_SET
-                    )
-                { // compatibility workaround
-                	*unsigned_flag= DATA_UNSIGNED;
-                	return DATA_INT;
-                }
-		return(DATA_FIXBINARY);
-	case HA_KEYTYPE_VARBINARY2:
-		if (field->type() != MYSQL_TYPE_VARCHAR)
-			return(DATA_BLOB);
-		/* fall through */
-	case HA_KEYTYPE_VARBINARY1:
-		return(DATA_BINARY);
-	case HA_KEYTYPE_VARTEXT2:
-		if (field->type() != MYSQL_TYPE_VARCHAR)
-			return(DATA_BLOB);
-		/* fall through */
-	case HA_KEYTYPE_VARTEXT1:
-		if (field->charset() == &my_charset_latin1) {
+	}
+
+	switch (field->type()) {
+		/* NOTE that we only allow string types in DATA_MYSQL and
+		DATA_VARMYSQL */
+	case MYSQL_TYPE_VAR_STRING:	/* old <= 4.1 VARCHAR */
+	case MYSQL_TYPE_VARCHAR:	/* new >= 5.0.3 true VARCHAR */
+		if (field->binary()) {
+			return(DATA_BINARY);
+		} else if (strcmp(field->charset()->name,
+				  "latin1_swedish_ci") == 0) {
 			return(DATA_VARCHAR);
 		} else {
 			return(DATA_VARMYSQL);
 		}
-	case HA_KEYTYPE_TEXT:
-		if (field->charset() == &my_charset_latin1) {
+	case MYSQL_TYPE_BIT:
+	case MYSQL_TYPE_STRING: if (field->binary()) {
+
+			return(DATA_FIXBINARY);
+		} else if (strcmp(field->charset()->name,
+				  "latin1_swedish_ci") == 0) {
 			return(DATA_CHAR);
 		} else {
 			return(DATA_MYSQL);
 		}
-	case HA_KEYTYPE_NUM:
+	case MYSQL_TYPE_NEWDECIMAL:
+		return(DATA_FIXBINARY);
+	case MYSQL_TYPE_LONG:
+	case MYSQL_TYPE_LONGLONG:
+	case MYSQL_TYPE_TINY:
+	case MYSQL_TYPE_SHORT:
+	case MYSQL_TYPE_INT24:
+	case MYSQL_TYPE_DATE:
+	case MYSQL_TYPE_YEAR:
+	case MYSQL_TYPE_NEWDATE:
+		return(DATA_INT);
+	case MYSQL_TYPE_TIMESTAMP:
+	case MYSQL_TYPE_TIME:
+	case MYSQL_TYPE_DATETIME:
+		if (field->key_type() == HA_KEYTYPE_BINARY)
+			return(DATA_FIXBINARY);
+                else
+			return(DATA_INT);
+	case MYSQL_TYPE_FLOAT:
+		return(DATA_FLOAT);
+	case MYSQL_TYPE_DOUBLE:
+		return(DATA_DOUBLE);
+	case MYSQL_TYPE_DECIMAL:
 		return(DATA_DECIMAL);
-	case HA_KEYTYPE_BIT:
-	case HA_KEYTYPE_END:
+	case MYSQL_TYPE_GEOMETRY:
+	case MYSQL_TYPE_TINY_BLOB:
+	case MYSQL_TYPE_MEDIUM_BLOB:
+	case MYSQL_TYPE_BLOB:
+	case MYSQL_TYPE_LONG_BLOB:
+		return(DATA_BLOB);
+	case MYSQL_TYPE_NULL:
+		/* MySQL currently accepts "NULL" datatype, but will
+		reject such datatype in the next release. We will cope
+		with it and not trigger assertion failure in 5.1 */
+		break;
+	default:
 		ut_error;
 	}
 
diff --git a/storage/innobase/handler/handler0alter.cc b/storage/innobase/handler/handler0alter.cc
index dd6525ae7c0..a120534b36d 100644
--- a/storage/innobase/handler/handler0alter.cc
+++ b/storage/innobase/handler/handler0alter.cc
@@ -347,6 +347,32 @@ ha_innobase::check_if_supported_inplace_alter(
 		}
 	}
 
+	/*
+	  InnoDB in different MariaDB versions was generating different mtype
+	  codes for certain types. In some cases the signed/unsigned bit was
+	  generated differently too.
+
+	  Online ALTER would change the mtype/unsigned_flag (to what the
+	  current code generates) without changing the underlying data
+	  represenation, and it might result in data corruption.
+
+	  Don't do online ALTER if mtype/unsigned_flag are wrong.
+	*/
+	for (ulint i = 0; i < table->s->fields; i++) {
+		const Field*		field = table->field[i];
+		const dict_col_t*	col = dict_table_get_nth_col(prebuilt->table, i);
+		ulint		unsigned_flag;
+		if (col->mtype != get_innobase_type_from_mysql_type(&unsigned_flag, field)) {
+
+			DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED);
+		}
+
+		if ((col->prtype & DATA_UNSIGNED) != unsigned_flag) {
+
+			DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED);
+		}
+	}
+
 	/* We should be able to do the operation in-place.
 	See if we can do it online (LOCK=NONE). */
 	bool	online = true;