MDEV-9393 Split Copy_field::get_copy_func() into virtual methods in Field

Also fixes:
MDEV-9391 InnoDB does not produce warnings when doing WHERE int_column=varchar_column
MDEV-9337 ALTER from DECIMAL and INT to DATETIME returns a wrong result
MDEV-9340 Copying from INT/DOUBLE to ENUM is inconsistent
MDEV-9392 Copying from DECIMAL to YEAR is not consistent about warnings

18 files changed, 828 insertions, 127 deletions

diff --git a/mysql-test/r/join_cache.result b/mysql-test/r/join_cache.result
index 90d305fb384..d816b1acf92 100644
--- a/mysql-test/r/join_cache.result
+++ b/mysql-test/r/join_cache.result
@@ -4691,6 +4691,9 @@ FROM t1 LEFT JOIN
 (t2 LEFT OUTER JOIN t3 ON t2.b = t3.b) ON t2.a = t1.b
 WHERE t3.a BETWEEN 3 AND 11 OR t1.a <= t2.c;
 a
+Warnings:
+Warning	1292	Truncated incorrect INTEGER value: 'h'
+Warning	1292	Truncated incorrect INTEGER value: 'j'
 SET SESSION optimizer_switch = 'outer_join_with_cache=off';
 SET SESSION join_cache_level = DEFAULT;
 DROP TABLE t1,t2,t3;
diff --git a/mysql-test/r/subselect_sj2.result b/mysql-test/r/subselect_sj2.result
index 21d97b3faea..98a8907f741 100644
--- a/mysql-test/r/subselect_sj2.result
+++ b/mysql-test/r/subselect_sj2.result
@@ -937,6 +937,8 @@ SELECT d FROM t2, t1
 WHERE a = d AND ( pk < 2 OR d = 'z' )
 );
 a	b	c
+Warnings:
+Warning	1292	Truncated incorrect INTEGER value: 'x'
 DROP TABLE t1, t2;
 #
 # BUG#951937: Wrong result (missing rows) with semijoin+materialization, IN subquery, InnoDB, TEMPTABLE view
diff --git a/mysql-test/r/subselect_sj2_jcl6.result b/mysql-test/r/subselect_sj2_jcl6.result
index eb91fe6d61b..1b8c1fc1158 100644
--- a/mysql-test/r/subselect_sj2_jcl6.result
+++ b/mysql-test/r/subselect_sj2_jcl6.result
@@ -952,6 +952,8 @@ SELECT d FROM t2, t1
 WHERE a = d AND ( pk < 2 OR d = 'z' )
 );
 a	b	c
+Warnings:
+Warning	1292	Truncated incorrect INTEGER value: 'x'
 DROP TABLE t1, t2;
 #
 # BUG#951937: Wrong result (missing rows) with semijoin+materialization, IN subquery, InnoDB, TEMPTABLE view
diff --git a/mysql-test/r/subselect_sj2_mat.result b/mysql-test/r/subselect_sj2_mat.result
index 16e8f88168d..ac38e57d60a 100644
--- a/mysql-test/r/subselect_sj2_mat.result
+++ b/mysql-test/r/subselect_sj2_mat.result
@@ -939,6 +939,8 @@ SELECT d FROM t2, t1
 WHERE a = d AND ( pk < 2 OR d = 'z' )
 );
 a	b	c
+Warnings:
+Warning	1292	Truncated incorrect INTEGER value: 'x'
 DROP TABLE t1, t2;
 #
 # BUG#951937: Wrong result (missing rows) with semijoin+materialization, IN subquery, InnoDB, TEMPTABLE view
diff --git a/mysql-test/r/type_datetime.result b/mysql-test/r/type_datetime.result
index 155e9535a0a..d0cd2c97510 100644
--- a/mysql-test/r/type_datetime.result
+++ b/mysql-test/r/type_datetime.result
@@ -1141,3 +1141,54 @@ DROP TABLE t1;
 #
 # End of 10.1 tests
 #
+#
+# Start of 10.2 tests
+#
+#
+# MDEV-9337 ALTER from DECIMAL and INT to DATETIME returns a wrong result
+#
+CREATE TABLE t1 (a DATETIME);
+INSERT INTO t1 VALUES (1000);
+SELECT * FROM t1;
+a
+2000-10-00 00:00:00
+DROP TABLE t1;
+CREATE TABLE t1 (a DATETIME);
+CREATE TABLE t2 (a INT);
+INSERT INTO t2 VALUES (1000);
+INSERT INTO t1 SELECT * FROM t2;
+SELECT * FROM t1;
+a
+2000-10-00 00:00:00
+DROP TABLE t1,t2;
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1000);
+ALTER TABLE t1 MODIFY a DATETIME;
+SELECT * FROM t1;
+a
+2000-10-00 00:00:00
+DROP TABLE t1;
+CREATE TABLE t1 (a DATETIME);
+INSERT INTO t1 VALUES (1000.0);
+SELECT * FROM t1;
+a
+2000-10-00 00:00:00
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 (a DATETIME);
+CREATE TABLE t2 (a DECIMAL(4,0));
+INSERT INTO t2 VALUES (1000);
+INSERT INTO t1 SELECT * FROM t2;
+SELECT * FROM t1;
+a
+2000-10-00 00:00:00
+DROP TABLE t1,t2;
+CREATE TABLE t1 (a DECIMAL(4,0));
+INSERT INTO t1 VALUES (1000);
+ALTER TABLE t1 MODIFY a DATETIME;
+SELECT * FROM t1;
+a
+2000-10-00 00:00:00
+DROP TABLE t1;
+#
+# End of 10.2 tests
+#
diff --git a/mysql-test/r/type_enum.result b/mysql-test/r/type_enum.result
index d901434fd6e..f0152d08c32 100644
--- a/mysql-test/r/type_enum.result
+++ b/mysql-test/r/type_enum.result
@@ -2134,3 +2134,84 @@ DROP TABLE t1;
 #
 # End of 10.1 tests
 #
+#
+# MDEV-9340 Copying from INT/DOUBLE to ENUM is inconsistent
+#
+CREATE TABLE t1 (a ENUM('9e200','9e100'));
+CREATE TABLE t2 (a DOUBLE);
+INSERT INTO t2 VALUES ('9e100');
+INSERT INTO t1 SELECT * FROM t2;
+Warnings:
+Warning	1265	Data truncated for column 'a' at row 1
+SELECT * FROM t1;
+a
+
+DROP TABLE t1,t2;
+CREATE TABLE t1 (a DOUBLE);
+INSERT INTO t1 VALUES (9e100);
+ALTER TABLE t1 MODIFY a ENUM('9e200','9e100');
+Warnings:
+Warning	1292	Truncated incorrect INTEGER value: '9e100'
+Warning	1265	Data truncated for column 'a' at row 1
+SELECT * FROM t1;
+a
+
+DROP TABLE t1;
+CREATE TABLE t1 (a ENUM('200','100'));
+CREATE TABLE t2 (a DOUBLE);
+INSERT INTO t2 VALUES ('100');
+INSERT INTO t1 SELECT * FROM t2;
+Warnings:
+Warning	1265	Data truncated for column 'a' at row 1
+SELECT * FROM t1;
+a
+
+DROP TABLE t1,t2;
+CREATE TABLE t1 (a ENUM('200','100'));
+CREATE TABLE t2 (a INT);
+INSERT INTO t2 VALUES ('100');
+INSERT INTO t1 SELECT * FROM t2;
+Warnings:
+Warning	1265	Data truncated for column 'a' at row 1
+SELECT * FROM t1;
+a
+
+DROP TABLE t1,t2;
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES ('200');
+ALTER TABLE t1 MODIFY a ENUM('200','100');
+Warnings:
+Warning	1265	Data truncated for column 'a' at row 1
+SELECT *FROM t1;
+a
+
+DROP TABLE t1;
+CREATE TABLE t1 (a ENUM('200','100'));
+CREATE TABLE t2 (a INT);
+INSERT INTO t2 VALUES ('100');
+INSERT INTO t1 SELECT * FROM t2;
+Warnings:
+Warning	1265	Data truncated for column 'a' at row 1
+SELECT * FROM t1;
+a
+
+DROP TABLE t1,t2;
+CREATE TABLE t1 (a ENUM('2001','2002'));
+CREATE TABLE t2 (a YEAR);
+INSERT INTO t2 VALUES ('2001');
+INSERT INTO t1 SELECT * FROM t2;
+Warnings:
+Warning	1265	Data truncated for column 'a' at row 1
+SELECT * FROM t1;
+a
+
+DROP TABLE t1,t2;
+CREATE TABLE t1 (a YEAR);
+INSERT INTO t1 VALUES ('2001');
+ALTER TABLE t1 MODIFY a ENUM('2001','2002');
+Warnings:
+Warning	1265	Data truncated for column 'a' at row 1
+SELECT * FROM t1;
+a
+
+DROP TABLE t1;
diff --git a/mysql-test/r/type_int.result b/mysql-test/r/type_int.result
index 4e7b928ac07..530a4134f4a 100644
--- a/mysql-test/r/type_int.result
+++ b/mysql-test/r/type_int.result
@@ -36,3 +36,60 @@ DROP TABLE t1;
 #
 # End of 10.1 tests
 #
+#
+# Start of 10.2 tests
+#
+#
+# MDEV-9393 Split Copy_field::get_copy_func() into virtual methods in Field
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (10.1),(10.9);
+SELECT * FROM t1;
+a
+10
+11
+DROP TABLE t1;
+CREATE TABLE t1 (a INT);
+CREATE TABLE t2 (a DECIMAL(10,2));
+INSERT INTO t2 VALUES (10.1),(10.9);
+INSERT INTO t1 SELECT a FROM t2;
+SELECT * FROM t1;
+a
+10
+11
+DROP TABLE t1,t2;
+CREATE TABLE t1 (a DECIMAL(10,2));
+INSERT INTO t1 VALUES (10.1),(10.9);
+ALTER TABLE t1 MODIFY a INT;
+SELECT * FROM t1;
+a
+10
+11
+DROP TABLE t1;
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (TIME'00:00:10.1'),(TIME'00:00:10.9');
+SELECT * FROM t1;
+a
+10
+10
+DROP TABLE t1;
+CREATE TABLE t1 (a INT);
+CREATE TABLE t2 (a TIME(1));
+INSERT INTO t2 VALUES (10.1),(10.9);
+INSERT INTO t1 SELECT a FROM t2;
+SELECT * FROM t1;
+a
+10
+10
+DROP TABLE t1,t2;
+CREATE TABLE t1 (a TIME(1));
+INSERT INTO t1 VALUES (10.1),(10.9);
+ALTER TABLE t1 MODIFY a INT;
+SELECT * FROM t1;
+a
+10
+10
+DROP TABLE t1;
+#
+# End of 10.2 tests
+#
diff --git a/mysql-test/r/type_num_innodb.result b/mysql-test/r/type_num_innodb.result
new file mode 100644
index 00000000000..581a387b2e8
--- /dev/null
+++ b/mysql-test/r/type_num_innodb.result
@@ -0,0 +1,107 @@
+#
+# Start of 10.2 tests
+#
+#
+# MDEV-9391 InnoDB does not produce warnings when doing WHERE int_column=varchar_column
+#
+CREATE TABLE t1 (
+a DOUBLE, b VARCHAR(1), c INT,
+KEY(a), KEY(b)
+) ENGINE=InnoDB;
+INSERT INTO t1 VALUES
+(1,'v',9),(2,'v',8),(3,'c',7),(4,'m',6),(5,'x',5),
+(6,'i',4),(7,'e',3),(8,'p',2),(9,'s',1),(10,'j',9),
+(11,'z',8),(12,'c',7),(13,'a',6),(14,'q',5),(15,'y',4),
+(16,'n',3),(17,'r',2),(18,'v',1),(19,'p',0);
+CREATE TABLE t2 (
+pk INT, d VARCHAR(1), e INT,
+PRIMARY KEY(pk), KEY(d,e)
+) ENGINE=InnoDB;
+INSERT INTO t2 VALUES
+(1,'x',1),(2,'d',2),(3,'r',3),(4,'f',4),(5,'y',5),
+(6,'u',6),(7,'m',7),(8,'k',8),(9,'o',9),(10,'w',1),
+(11,'m',2),(12,'q',3),(13,'m',4),(14,'d',5),
+(15,'g',6),(16,'x',7),(17,'f',8);
+SELECT * FROM t1,t2 WHERE a=d;
+a	b	c	pk	d	e
+Warnings:
+Warning	1292	Truncated incorrect DOUBLE value: 'd'
+Warning	1292	Truncated incorrect DOUBLE value: 'd'
+Warning	1292	Truncated incorrect DOUBLE value: 'f'
+Warning	1292	Truncated incorrect DOUBLE value: 'f'
+Warning	1292	Truncated incorrect DOUBLE value: 'g'
+Warning	1292	Truncated incorrect DOUBLE value: 'k'
+Warning	1292	Truncated incorrect DOUBLE value: 'm'
+Warning	1292	Truncated incorrect DOUBLE value: 'm'
+Warning	1292	Truncated incorrect DOUBLE value: 'm'
+Warning	1292	Truncated incorrect DOUBLE value: 'o'
+Warning	1292	Truncated incorrect DOUBLE value: 'q'
+Warning	1292	Truncated incorrect DOUBLE value: 'r'
+Warning	1292	Truncated incorrect DOUBLE value: 'u'
+Warning	1292	Truncated incorrect DOUBLE value: 'w'
+Warning	1292	Truncated incorrect DOUBLE value: 'x'
+Warning	1292	Truncated incorrect DOUBLE value: 'x'
+Warning	1292	Truncated incorrect DOUBLE value: 'y'
+ALTER TABLE t1 MODIFY a DECIMAL(10,0);
+SELECT * FROM t1,t2 WHERE a=d;
+a	b	c	pk	d	e
+Warnings:
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'd'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'd'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'f'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'f'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'g'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'k'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'm'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'm'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'm'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'o'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'q'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'r'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'u'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'w'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'x'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'x'
+Warning	1918	Encountered illegal value '' when converting to DECIMAL
+Warning	1292	Truncated incorrect DECIMAL value: 'y'
+ALTER TABLE t1 MODIFY a DOUBLE;
+SELECT * FROM t1,t2 WHERE a=d;
+a	b	c	pk	d	e
+Warnings:
+Warning	1292	Truncated incorrect DOUBLE value: 'd'
+Warning	1292	Truncated incorrect DOUBLE value: 'd'
+Warning	1292	Truncated incorrect DOUBLE value: 'f'
+Warning	1292	Truncated incorrect DOUBLE value: 'f'
+Warning	1292	Truncated incorrect DOUBLE value: 'g'
+Warning	1292	Truncated incorrect DOUBLE value: 'k'
+Warning	1292	Truncated incorrect DOUBLE value: 'm'
+Warning	1292	Truncated incorrect DOUBLE value: 'm'
+Warning	1292	Truncated incorrect DOUBLE value: 'm'
+Warning	1292	Truncated incorrect DOUBLE value: 'o'
+Warning	1292	Truncated incorrect DOUBLE value: 'q'
+Warning	1292	Truncated incorrect DOUBLE value: 'r'
+Warning	1292	Truncated incorrect DOUBLE value: 'u'
+Warning	1292	Truncated incorrect DOUBLE value: 'w'
+Warning	1292	Truncated incorrect DOUBLE value: 'x'
+Warning	1292	Truncated incorrect DOUBLE value: 'x'
+Warning	1292	Truncated incorrect DOUBLE value: 'y'
+DROP TABLE t1,t2;
+#
+# End of 10.2 tests
+#
diff --git a/mysql-test/r/type_time.result b/mysql-test/r/type_time.result
index bdcffc8d824..e4347509d5e 100644
--- a/mysql-test/r/type_time.result
+++ b/mysql-test/r/type_time.result
@@ -1217,3 +1217,32 @@ DROP TABLE t1;
 #
 # End of 10.1 tests
 #
+#
+# Start of 10.2 tests
+#
+#
+# MDEV-9393 Split Copy_field::get_copy_func() into virtual methods in Field
+#
+CREATE TABLE t1 (a YEAR, b TIME, c YEAR);
+CREATE TABLE t2 (a YEAR);
+INSERT INTO t2 VALUES (0),(1999),(2000),(2030),(2050),(2070);
+INSERT INTO t1 (a,b,c) SELECT a,a,a FROM t2;
+Warnings:
+Warning	1265	Data truncated for column 'b' at row 2
+Warning	1265	Data truncated for column 'b' at row 6
+ALTER TABLE t1 MODIFY c TIME;
+Warnings:
+Warning	1265	Data truncated for column 'c' at row 2
+Warning	1265	Data truncated for column 'c' at row 6
+SELECT * FROM t1;
+a	b	c
+0000	00:00:00	00:00:00
+1999	00:00:00	00:00:00
+2000	00:20:00	00:20:00
+2030	00:20:30	00:20:30
+2050	00:20:50	00:20:50
+2070	00:00:00	00:00:00
+DROP TABLE t1,t2;
+#
+# End of 10.2 tests
+#
diff --git a/mysql-test/r/type_year.result b/mysql-test/r/type_year.result
index 842a16e3b4a..4d28a7b8d25 100644
--- a/mysql-test/r/type_year.result
+++ b/mysql-test/r/type_year.result
@@ -438,3 +438,48 @@ DROP TABLE t1;
 #
 # End of 10.1 tests
 #
+#
+# Start of 10.2 tests
+#
+#
+# MDEV-9392 Copying from DECIMAL to YEAR is not consistent about warnings
+#
+CREATE TABLE t1 (a YEAR);
+INSERT INTO t1 VALUES (-0.1);
+Warnings:
+Warning	1264	Out of range value for column 'a' at row 1
+DROP TABLE t1;
+CREATE TABLE t1 (a YEAR);
+CREATE TABLE t2 (a DECIMAL(10,1));
+INSERT INTO t2 VALUES (-0.1);
+INSERT INTO t1 SELECT * FROM t2;
+Warnings:
+Warning	1264	Out of range value for column 'a' at row 1
+DROP TABLE t1,t2;
+CREATE TABLE t1 (a DECIMAL(10,1));
+INSERT INTO t1 VALUES (-0.1);
+ALTER TABLE t1 MODIFY a YEAR;
+Warnings:
+Warning	1264	Out of range value for column 'a' at row 1
+DROP TABLE t1;
+CREATE TABLE t1 (a YEAR);
+INSERT INTO t1 VALUES (-0.1e0);
+Warnings:
+Warning	1264	Out of range value for column 'a' at row 1
+DROP TABLE t1;
+CREATE TABLE t1 (a YEAR);
+CREATE TABLE t2 (a DOUBLE);
+INSERT INTO t2 VALUES (-0.1);
+INSERT INTO t1 SELECT * FROM t2;
+Warnings:
+Warning	1264	Out of range value for column 'a' at row 1
+DROP TABLE t1,t2;
+CREATE TABLE t1 (a DOUBLE);
+INSERT INTO t1 VALUES (-0.1);
+ALTER TABLE t1 MODIFY a YEAR;
+Warnings:
+Warning	1264	Out of range value for column 'a' at row 1
+DROP TABLE t1;
+#
+# End of 10.2 tests
+#
diff --git a/mysql-test/t/type_datetime.test b/mysql-test/t/type_datetime.test
index 444ab02d223..7c9d56a0780 100644
--- a/mysql-test/t/type_datetime.test
+++ b/mysql-test/t/type_datetime.test
@@ -695,3 +695,51 @@ DROP TABLE t1;
 --echo #
 --echo # End of 10.1 tests
 --echo #
+
+--echo #
+--echo # Start of 10.2 tests
+--echo #
+
+--echo #
+--echo # MDEV-9337 ALTER from DECIMAL and INT to DATETIME returns a wrong result
+--echo #
+CREATE TABLE t1 (a DATETIME);
+INSERT INTO t1 VALUES (1000);
+SELECT * FROM t1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a DATETIME);
+CREATE TABLE t2 (a INT);
+INSERT INTO t2 VALUES (1000);
+INSERT INTO t1 SELECT * FROM t2;
+SELECT * FROM t1;
+DROP TABLE t1,t2;
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1000);
+ALTER TABLE t1 MODIFY a DATETIME;
+SELECT * FROM t1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a DATETIME);
+INSERT INTO t1 VALUES (1000.0);
+SELECT * FROM t1;
+DROP TABLE IF EXISTS t1;
+
+CREATE TABLE t1 (a DATETIME);
+CREATE TABLE t2 (a DECIMAL(4,0));
+INSERT INTO t2 VALUES (1000);
+INSERT INTO t1 SELECT * FROM t2;
+SELECT * FROM t1;
+DROP TABLE t1,t2;
+
+CREATE TABLE t1 (a DECIMAL(4,0));
+INSERT INTO t1 VALUES (1000);
+ALTER TABLE t1 MODIFY a DATETIME;
+SELECT * FROM t1;
+DROP TABLE t1;
+
+
+--echo #
+--echo # End of 10.2 tests
+--echo #
diff --git a/mysql-test/t/type_enum.test b/mysql-test/t/type_enum.test
index 314cb237dd3..63e9e9e7b09 100644
--- a/mysql-test/t/type_enum.test
+++ b/mysql-test/t/type_enum.test
@@ -388,3 +388,65 @@ DROP TABLE t1;
 --echo #
 --echo # End of 10.1 tests
 --echo #
+
+
+--echo #
+--echo # MDEV-9340 Copying from INT/DOUBLE to ENUM is inconsistent
+--echo #
+
+# DOUBLE -> ENUM
+CREATE TABLE t1 (a ENUM('9e200','9e100'));
+CREATE TABLE t2 (a DOUBLE);
+INSERT INTO t2 VALUES ('9e100');
+INSERT INTO t1 SELECT * FROM t2;
+SELECT * FROM t1;
+DROP TABLE t1,t2;
+
+CREATE TABLE t1 (a DOUBLE);
+INSERT INTO t1 VALUES (9e100);
+ALTER TABLE t1 MODIFY a ENUM('9e200','9e100');
+SELECT * FROM t1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a ENUM('200','100'));
+CREATE TABLE t2 (a DOUBLE);
+INSERT INTO t2 VALUES ('100');
+INSERT INTO t1 SELECT * FROM t2;
+SELECT * FROM t1;
+DROP TABLE t1,t2;
+
+# INT -> ENUM
+CREATE TABLE t1 (a ENUM('200','100'));
+CREATE TABLE t2 (a INT);
+INSERT INTO t2 VALUES ('100');
+INSERT INTO t1 SELECT * FROM t2;
+SELECT * FROM t1;
+DROP TABLE t1,t2;
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES ('200');
+ALTER TABLE t1 MODIFY a ENUM('200','100');
+SELECT *FROM t1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a ENUM('200','100'));
+CREATE TABLE t2 (a INT);
+INSERT INTO t2 VALUES ('100');
+INSERT INTO t1 SELECT * FROM t2;
+SELECT * FROM t1;
+DROP TABLE t1,t2;
+
+
+# YEAR -> ENUM
+CREATE TABLE t1 (a ENUM('2001','2002'));
+CREATE TABLE t2 (a YEAR);
+INSERT INTO t2 VALUES ('2001');
+INSERT INTO t1 SELECT * FROM t2;
+SELECT * FROM t1;
+DROP TABLE t1,t2;
+
+CREATE TABLE t1 (a YEAR);
+INSERT INTO t1 VALUES ('2001');
+ALTER TABLE t1 MODIFY a ENUM('2001','2002');
+SELECT * FROM t1;
+DROP TABLE t1;
diff --git a/mysql-test/t/type_int.test b/mysql-test/t/type_int.test
index e8b9b2cffcd..271b4d5862a 100644
--- a/mysql-test/t/type_int.test
+++ b/mysql-test/t/type_int.test
@@ -26,3 +26,53 @@ DROP TABLE t1;
 --echo #
 --echo # End of 10.1 tests
 --echo #
+
+--echo #
+--echo # Start of 10.2 tests
+--echo #
+
+--echo #
+--echo # MDEV-9393 Split Copy_field::get_copy_func() into virtual methods in Field
+--echo #
+
+# DECIMAL -> INT
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (10.1),(10.9);
+SELECT * FROM t1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a INT);
+CREATE TABLE t2 (a DECIMAL(10,2));
+INSERT INTO t2 VALUES (10.1),(10.9);
+INSERT INTO t1 SELECT a FROM t2;
+SELECT * FROM t1;
+DROP TABLE t1,t2;
+
+CREATE TABLE t1 (a DECIMAL(10,2));
+INSERT INTO t1 VALUES (10.1),(10.9);
+ALTER TABLE t1 MODIFY a INT;
+SELECT * FROM t1;
+DROP TABLE t1;
+
+# TIME -> INT
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (TIME'00:00:10.1'),(TIME'00:00:10.9');
+SELECT * FROM t1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a INT);
+CREATE TABLE t2 (a TIME(1));
+INSERT INTO t2 VALUES (10.1),(10.9);
+INSERT INTO t1 SELECT a FROM t2;
+SELECT * FROM t1;
+DROP TABLE t1,t2;
+
+CREATE TABLE t1 (a TIME(1));
+INSERT INTO t1 VALUES (10.1),(10.9);
+ALTER TABLE t1 MODIFY a INT;
+SELECT * FROM t1;
+DROP TABLE t1;
+
+--echo #
+--echo # End of 10.2 tests
+--echo #
diff --git a/mysql-test/t/type_num_innodb.test b/mysql-test/t/type_num_innodb.test
new file mode 100644
index 00000000000..04bdd4c63b0
--- /dev/null
+++ b/mysql-test/t/type_num_innodb.test
@@ -0,0 +1,41 @@
+--source include/have_innodb.inc
+
+--echo #
+--echo # Start of 10.2 tests
+--echo #
+
+--echo #
+--echo # MDEV-9391 InnoDB does not produce warnings when doing WHERE int_column=varchar_column
+--echo #
+
+CREATE TABLE t1 (
+  a DOUBLE, b VARCHAR(1), c INT,
+  KEY(a), KEY(b)
+) ENGINE=InnoDB;
+INSERT INTO t1 VALUES
+(1,'v',9),(2,'v',8),(3,'c',7),(4,'m',6),(5,'x',5),
+(6,'i',4),(7,'e',3),(8,'p',2),(9,'s',1),(10,'j',9),
+(11,'z',8),(12,'c',7),(13,'a',6),(14,'q',5),(15,'y',4),
+(16,'n',3),(17,'r',2),(18,'v',1),(19,'p',0);
+CREATE TABLE t2 (
+  pk INT, d VARCHAR(1), e INT,
+  PRIMARY KEY(pk), KEY(d,e)
+) ENGINE=InnoDB;
+INSERT INTO t2 VALUES
+(1,'x',1),(2,'d',2),(3,'r',3),(4,'f',4),(5,'y',5),
+(6,'u',6),(7,'m',7),(8,'k',8),(9,'o',9),(10,'w',1),
+(11,'m',2),(12,'q',3),(13,'m',4),(14,'d',5),
+(15,'g',6),(16,'x',7),(17,'f',8);
+SELECT * FROM t1,t2 WHERE a=d;
+
+ALTER TABLE t1 MODIFY a DECIMAL(10,0);
+SELECT * FROM t1,t2 WHERE a=d;
+
+ALTER TABLE t1 MODIFY a DOUBLE;
+SELECT * FROM t1,t2 WHERE a=d;
+
+DROP TABLE t1,t2;
+
+--echo #
+--echo # End of 10.2 tests
+--echo #
diff --git a/mysql-test/t/type_time.test b/mysql-test/t/type_time.test
index 27679b9ec5a..c4b93d6dbb2 100644
--- a/mysql-test/t/type_time.test
+++ b/mysql-test/t/type_time.test
@@ -726,3 +726,25 @@ DROP TABLE t1;
 --echo #
 --echo # End of 10.1 tests
 --echo #
+
+--echo #
+--echo # Start of 10.2 tests
+--echo #
+
+
+--echo #
+--echo # MDEV-9393 Split Copy_field::get_copy_func() into virtual methods in Field
+--echo #
+
+CREATE TABLE t1 (a YEAR, b TIME, c YEAR);
+CREATE TABLE t2 (a YEAR);
+INSERT INTO t2 VALUES (0),(1999),(2000),(2030),(2050),(2070);
+INSERT INTO t1 (a,b,c) SELECT a,a,a FROM t2;
+ALTER TABLE t1 MODIFY c TIME;
+SELECT * FROM t1;
+DROP TABLE t1,t2;
+
+
+--echo #
+--echo # End of 10.2 tests
+--echo #
diff --git a/mysql-test/t/type_year.test b/mysql-test/t/type_year.test
index d9fa2af1eb4..22f164a757c 100644
--- a/mysql-test/t/type_year.test
+++ b/mysql-test/t/type_year.test
@@ -210,3 +210,45 @@ DROP TABLE t1;
 --echo #
 --echo # End of 10.1 tests
 --echo #
+
+--echo #
+--echo # Start of 10.2 tests
+--echo #
+
+--echo #
+--echo # MDEV-9392 Copying from DECIMAL to YEAR is not consistent about warnings
+--echo #
+CREATE TABLE t1 (a YEAR);
+INSERT INTO t1 VALUES (-0.1);
+DROP TABLE t1;
+
+CREATE TABLE t1 (a YEAR);
+CREATE TABLE t2 (a DECIMAL(10,1));
+INSERT INTO t2 VALUES (-0.1);
+INSERT INTO t1 SELECT * FROM t2;
+DROP TABLE t1,t2;
+
+CREATE TABLE t1 (a DECIMAL(10,1));
+INSERT INTO t1 VALUES (-0.1);
+ALTER TABLE t1 MODIFY a YEAR;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a YEAR);
+INSERT INTO t1 VALUES (-0.1e0);
+DROP TABLE t1;
+
+CREATE TABLE t1 (a YEAR);
+CREATE TABLE t2 (a DOUBLE);
+INSERT INTO t2 VALUES (-0.1);
+INSERT INTO t1 SELECT * FROM t2;
+DROP TABLE t1,t2;
+
+CREATE TABLE t1 (a DOUBLE);
+INSERT INTO t1 VALUES (-0.1);
+ALTER TABLE t1 MODIFY a YEAR;
+DROP TABLE t1;
+
+
+--echo #
+--echo # End of 10.2 tests
+--echo #
diff --git a/sql/field.h b/sql/field.h
index 7daf7da01cb..435ea20825a 100644
--- a/sql/field.h
+++ b/sql/field.h
@@ -33,6 +33,7 @@
 #include "compat56.h"
 
 class Send_field;
+class Copy_field;
 class Protocol;
 class Create_field;
 class Relay_log_info;
@@ -621,6 +622,11 @@ protected:
     val_str(&result);
     return to->store(result.ptr(), result.length(), charset());
   }
+  static void do_field_int(Copy_field *copy);
+  static void do_field_real(Copy_field *copy);
+  static void do_field_string(Copy_field *copy);
+  static void do_field_temporal(Copy_field *copy);
+  static void do_field_decimal(Copy_field *copy);
 public:
   static void *operator new(size_t size, MEM_ROOT *mem_root) throw ()
   { return alloc_root(mem_root, size); }
@@ -733,6 +739,12 @@ public:
         uchar null_bit_arg, utype unireg_check_arg,
         const char *field_name_arg);
   virtual ~Field() {}
+  /**
+    Convenience definition of a copy function returned by
+    Field::get_copy_func()
+  */
+  typedef void Copy_func(Copy_field*);
+  virtual Copy_func *get_copy_func(const Field *from) const= 0;
   /* Store functions returns 1 on overflow and -1 on fatal error */
   virtual int  store_field(Field *from) { return from->save_in_field(this); }
   virtual int  save_in_field(Field *to)= 0;
@@ -1265,6 +1277,7 @@ protected:
     return (op_result == E_DEC_OVERFLOW);
   }
   int warn_if_overflow(int op_result);
+  Copy_func *get_identical_copy_func() const;
 public:
   void set_table_name(String *alias)
   {
@@ -1528,6 +1541,10 @@ public:
   uint decimals() const { return (uint) dec; }
   uint size_of() const { return sizeof(*this); }
   bool eq_def(const Field *field) const;
+  Copy_func *get_copy_func(const Field *from) const
+  {
+    return do_field_int;
+  }
   int save_in_field(Field *to)
   {
     return to->store(val_int(), MY_TEST(flags & UNSIGNED_FLAG));
@@ -1678,6 +1695,10 @@ public:
     not_fixed(dec_arg >= NOT_FIXED_DEC)
     {}
   Item_result result_type () const { return REAL_RESULT; }
+  Copy_func *get_copy_func(const Field *from) const
+  {
+    return do_field_real;
+  }
   int save_in_field(Field *to) { return to->store(val_real()); }
   int store_decimal(const my_decimal *);
   int  store_time_dec(MYSQL_TIME *ltime, uint dec);
@@ -1703,6 +1724,10 @@ public:
   enum_field_types type() const { return MYSQL_TYPE_DECIMAL;}
   enum ha_base_keytype key_type() const
   { return zerofill ? HA_KEYTYPE_BINARY : HA_KEYTYPE_NUM; }
+  Copy_func *get_copy_func(const Field *from) const
+  {
+    return eq_def(from) ? get_identical_copy_func() : do_field_string;
+  }
   int reset(void);
   int store(const char *to,uint length,CHARSET_INFO *charset);
   int store(double nr);
@@ -1746,6 +1771,12 @@ public:
   enum_field_types type() const { return MYSQL_TYPE_NEWDECIMAL;}
   enum ha_base_keytype key_type() const { return HA_KEYTYPE_BINARY; }
   Item_result result_type () const { return DECIMAL_RESULT; }
+  Copy_func *get_copy_func(const Field *from) const
+  {
+    //  if (from->real_type() == MYSQL_TYPE_BIT) // QQ: why?
+    //    return do_field_int;
+    return do_field_decimal;
+  }
   int save_in_field(Field *to)
   {
     my_decimal buff;
@@ -2092,6 +2123,10 @@ public:
 	       unireg_check_arg, field_name_arg, cs)
     {}
   enum_field_types type() const { return MYSQL_TYPE_NULL;}
+  Copy_func *get_copy_func(const Field *from) const
+  {
+    return do_field_string;
+  }
   int  store(const char *to, uint length, CHARSET_INFO *cs)
   { null[0]=1; return 0; }
   int store(double nr)   { null[0]=1; return 0; }
@@ -2142,6 +2177,7 @@ public:
   {
     return store(str, length, &my_charset_bin);
   }
+  Copy_func *get_copy_func(const Field *from) const;
   int save_in_field(Field *to)
   {
     MYSQL_TIME ltime;
@@ -2413,6 +2449,28 @@ public:
 		unireg_check_arg, field_name_arg, 1, 1)
     {}
   enum_field_types type() const { return MYSQL_TYPE_YEAR;}
+  Copy_func *get_copy_func(const Field *from) const
+  {
+    if (eq_def(from))
+      return get_identical_copy_func();
+    switch (from->cmp_type()) {
+    case STRING_RESULT:
+      return do_field_string;
+    case TIME_RESULT:
+      return do_field_temporal;
+    case DECIMAL_RESULT:
+      return do_field_decimal;
+    case REAL_RESULT:
+      return do_field_real;
+    case INT_RESULT:
+      break;
+    case ROW_RESULT:
+    default:
+      DBUG_ASSERT(0);
+      break;
+    }
+    return do_field_int;
+  }
   int  store(const char *to,uint length,CHARSET_INFO *charset);
   int  store(double nr);
   int  store(longlong nr, bool unsigned_val);
@@ -2502,6 +2560,7 @@ protected:
   int store_TIME_with_warning(MYSQL_TIME *ltime, const ErrConv *str,
                               int was_cut, int have_smth_to_conv);
   bool check_zero_in_date_with_warn(ulonglong fuzzydate);
+  static void do_field_time(Copy_field *copy);
 public:
   Field_time(uchar *ptr_arg, uint length_arg, uchar *null_ptr_arg,
              uchar null_bit_arg, enum utype unireg_check_arg,
@@ -2511,6 +2570,14 @@ public:
     {}
   enum_field_types type() const { return MYSQL_TYPE_TIME;}
   enum ha_base_keytype key_type() const { return HA_KEYTYPE_INT24; }
+  Copy_func *get_copy_func(const Field *from) const
+  {
+    return from->cmp_type() == REAL_RESULT ? do_field_string : // MDEV-9344
+           from->type() == MYSQL_TYPE_YEAR ? do_field_int :
+           from->type() == MYSQL_TYPE_BIT  ? do_field_int :
+           eq_def(from)                    ? get_identical_copy_func() :
+                                             do_field_time;
+  }
   bool memcpy_field_possible(const Field *from) const
   {
     return real_type() == from->real_type() &&
@@ -2884,6 +2951,7 @@ public:
   enum ha_base_keytype key_type() const
     { return binary() ? HA_KEYTYPE_BINARY : HA_KEYTYPE_TEXT; }
   bool zero_pack() const { return 0; }
+  Copy_func *get_copy_func(const Field *from) const;
   int reset(void)
   {
     charset()->cset->fill(charset(),(char*) ptr, field_length,
@@ -2980,6 +3048,7 @@ public:
     return (uint32) field_length + (field_charset == &my_charset_bin ?
                                     length_bytes : 0);
   }
+  Copy_func *get_copy_func(const Field *from) const;
   bool memcpy_field_possible(const Field *from) const
   {
     return Field_str::memcpy_field_possible(from) &&
@@ -3037,7 +3106,9 @@ protected:
     The 'value'-object is a cache fronting the storage engine.
   */
   String value;
-  
+
+  static void do_copy_blob(Copy_field *copy);
+  static void do_conv_blob(Copy_field *copy);
 public:
   Field_blob(uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg,
 	     enum utype unireg_check_arg, const char *field_name_arg,
@@ -3072,6 +3143,19 @@ public:
   enum_field_types type() const { return MYSQL_TYPE_BLOB;}
   enum ha_base_keytype key_type() const
     { return binary() ? HA_KEYTYPE_VARBINARY2 : HA_KEYTYPE_VARTEXT2; }
+  Copy_func *get_copy_func(const Field *from) const
+  {
+    /*
+    TODO: MDEV-9331
+    if (from->type() == MYSQL_TYPE_BIT)
+      return do_field_int;
+    */
+    if (!(from->flags & BLOB_FLAG) || from->charset() != charset())
+      return do_conv_blob;
+    if (from->pack_length() != Field_blob::pack_length())
+      return do_copy_blob;
+    return get_identical_copy_func();
+  }
   int  store_field(Field *from)
   {                                             // Be sure the value is stored
     from->val_str(&value);
@@ -3258,6 +3342,7 @@ uint gis_field_options_read(const uchar *buf, uint buf_len,
 
 
 class Field_enum :public Field_str {
+  static void do_field_enum(Copy_field *copy_field);
 protected:
   uint packlength;
 public:
@@ -3278,6 +3363,17 @@ public:
   enum_field_types type() const { return MYSQL_TYPE_STRING; }
   enum Item_result cmp_type () const { return INT_RESULT; }
   enum ha_base_keytype key_type() const;
+  Copy_func *get_copy_func(const Field *from) const
+  {
+    if (eq_def(from))
+      return get_identical_copy_func();
+    if (real_type() == MYSQL_TYPE_ENUM &&
+        from->real_type() == MYSQL_TYPE_ENUM)
+      return do_field_enum;
+    if (from->result_type() == STRING_RESULT)
+      return do_field_string;
+    return do_field_int;
+  }
   int store_field(Field *from)
   {
     if (from->real_type() == MYSQL_TYPE_ENUM && from->val_int() == 0)
@@ -3409,6 +3505,10 @@ public:
       clr_rec_bits(bit_ptr, bit_ofs, bit_len);
     return 0; 
   }
+  Copy_func *get_copy_func(const Field *from) const
+  {
+    return do_field_int;
+  }
   int save_in_field(Field *to) { return to->store(val_int(), true); }
   bool memcpy_field_possible(const Field *from) const { return false; }
   int store(const char *to, uint length, CHARSET_INFO *charset);
@@ -3702,12 +3802,6 @@ class Send_field :public Sql_alloc {
 */
 
 class Copy_field :public Sql_alloc {
-  /**
-    Convenience definition of a copy function returned by
-    get_copy_func.
-  */
-  typedef void Copy_func(Copy_field*);
-  Copy_func *get_copy_func(const Field *to, const Field *from);
 public:
   uchar *from_ptr,*to_ptr;
   uchar *from_null_ptr,*to_null_ptr;
@@ -3728,7 +3822,7 @@ public:
 
     Note that for VARCHARs, do_copy() will be do_varstring*() which
     only copies the length-bytes (1 or 2) + the actual length of the
-    text instead of from/to_length bytes. @see get_copy_func()
+    text instead of from/to_length bytes.
   */
   uint from_length,to_length;
   Field *from_field,*to_field;
diff --git a/sql/field_conv.cc b/sql/field_conv.cc
index 21f46bbbedb..ecad05c7530 100644
--- a/sql/field_conv.cc
+++ b/sql/field_conv.cc
@@ -335,12 +335,12 @@ static void do_copy_next_number(Copy_field *copy)
 }
 
 
-static void do_copy_blob(Copy_field *copy)
+void Field_blob::do_copy_blob(Copy_field *copy)
 {
   ((Field_blob*) copy->to_field)->copy_value(((Field_blob*) copy->from_field));
 }
 
-static void do_conv_blob(Copy_field *copy)
+void Field_blob::do_conv_blob(Copy_field *copy)
 {
   copy->from_field->val_str(&copy->tmp);
   ((Field_blob *) copy->to_field)->store(copy->tmp.ptr(),
@@ -362,7 +362,7 @@ static void do_save_blob(Copy_field *copy)
 }
 
 
-static void do_field_string(Copy_field *copy)
+void Field::do_field_string(Copy_field *copy)
 {
   char buff[MAX_FIELD_WIDTH];
   String res(buff, sizeof(buff), copy->from_field->charset());
@@ -373,7 +373,7 @@ static void do_field_string(Copy_field *copy)
 }
 
 
-static void do_field_enum(Copy_field *copy)
+void Field_enum::do_field_enum(Copy_field *copy)
 {
   if (copy->from_field->val_int() == 0)
     ((Field_enum *) copy->to_field)->store_type((ulonglong) 0);
@@ -397,32 +397,45 @@ static void do_field_varbinary_pre50(Copy_field *copy)
 }
 
 
-static void do_field_int(Copy_field *copy)
+void Field::do_field_int(Copy_field *copy)
 {
   longlong value= copy->from_field->val_int();
   copy->to_field->store(value,
                         MY_TEST(copy->from_field->flags & UNSIGNED_FLAG));
 }
 
-static void do_field_real(Copy_field *copy)
+void Field::do_field_real(Copy_field *copy)
 {
   double value=copy->from_field->val_real();
   copy->to_field->store(value);
 }
 
 
-static void do_field_decimal(Copy_field *copy)
+void Field::do_field_decimal(Copy_field *copy)
 {
   my_decimal value;
   copy->to_field->store_decimal(copy->from_field->val_decimal(&value));
 }
 
 
-static void do_field_temporal(Copy_field *copy)
+void Field::do_field_temporal(Copy_field *copy)
 {
   MYSQL_TIME ltime;
-  copy->from_field->get_date(&ltime, 0);
-  copy->to_field->store_time_dec(&ltime, copy->from_field->decimals());
+  // TODO: we now need to check result
+  if (copy->from_field->get_date(&ltime, 0))
+    copy->to_field->reset();
+  else
+    copy->to_field->store_time_dec(&ltime, copy->from_field->decimals());
+}
+
+
+void Field_time::do_field_time(Copy_field *copy)
+{
+  MYSQL_TIME ltime;
+  if (copy->from_field->get_date(&ltime, TIME_TIME_ONLY))
+    copy->to_field->reset();
+  else
+    copy->to_field->store_time_dec(&ltime, copy->from_field->decimals());
 }
 
 
@@ -698,122 +711,72 @@ void Copy_field::set(Field *to,Field *from,bool save)
   if ((to->flags & BLOB_FLAG) && save)
     do_copy2= do_save_blob;
   else
-    do_copy2= get_copy_func(to,from);
+    do_copy2= to->get_copy_func(from);
   if (!do_copy)					// Not null
     do_copy=do_copy2;
 }
 
 
-Copy_field::Copy_func *
-Copy_field::get_copy_func(const Field *to, const Field *from)
+Field::Copy_func *Field_temporal::get_copy_func(const Field *from) const
+{
+  /* If types are not 100 % identical then convert trough get_date() */
+  if (from->cmp_type() == REAL_RESULT)
+    return do_field_string; // TODO: MDEV-9344
+  if (from->type() == MYSQL_TYPE_YEAR)
+    return do_field_string; // TODO: MDEV-9343
+  if (from->type() == MYSQL_TYPE_BIT)
+    return do_field_int;
+  if (!eq_def(from) ||
+      (table->in_use->variables.sql_mode &
+       (MODE_NO_ZERO_IN_DATE | MODE_NO_ZERO_DATE)))
+    return do_field_temporal;
+  return get_identical_copy_func();
+}
+
+
+Field::Copy_func *Field_varstring::get_copy_func(const Field *from) const
+{
+  if (from->type() == MYSQL_TYPE_BIT)
+    return do_field_int;
+  /*
+    Detect copy from pre 5.0 varbinary to varbinary as of 5.0 and
+    use special copy function that removes trailing spaces and thus
+    repairs data.
+  */
+  if (from->type() == MYSQL_TYPE_VAR_STRING && !from->has_charset() &&
+      !Field_varstring::has_charset())
+    return do_field_varbinary_pre50;
+  if (Field_varstring::real_type() != from->real_type() ||
+      Field_varstring::charset() != from->charset() ||
+      length_bytes != ((const Field_varstring*) from)->length_bytes)
+    return do_field_string;
+  return length_bytes == 1 ?
+         (from->charset()->mbmaxlen == 1 ? do_varstring1 : do_varstring1_mb) :
+         (from->charset()->mbmaxlen == 1 ? do_varstring2 : do_varstring2_mb);
+}
+
+
+Field::Copy_func *Field_string::get_copy_func(const Field *from) const
+{
+  if (from->type() == MYSQL_TYPE_BIT)
+    return do_field_int;
+  if (Field_string::real_type() != from->real_type() ||
+      Field_string::charset() != from->charset())
+    return do_field_string;
+  if (Field_string::pack_length() < from->pack_length())
+    return (Field_string::charset()->mbmaxlen == 1 ?
+            do_cut_string : do_cut_string_complex);
+  if (Field_string::pack_length() > from->pack_length())
+    return Field_string::charset() == &my_charset_bin ? do_expand_binary :
+                                                        do_expand_string;
+  return get_identical_copy_func();
+}
+
+
+Field::Copy_func *Field::get_identical_copy_func() const
 {
-  if (to->flags & BLOB_FLAG)
-  {
-    if (!(from->flags & BLOB_FLAG) || from->charset() != to->charset())
-      return do_conv_blob;
-    if (from_length != to_length)
-      return do_copy_blob;
-  }
-  else
-  {
-    if (to->real_type() == MYSQL_TYPE_BIT ||
-        from->real_type() == MYSQL_TYPE_BIT)
-      return do_field_int;
-    if (to->result_type() == DECIMAL_RESULT)
-      return do_field_decimal;
-    if (from->cmp_type() == TIME_RESULT)
-    {
-      /* If types are not 100 % identical then convert trough get_date() */
-      if (!to->eq_def(from) ||
-          ((to->table->in_use->variables.sql_mode &
-            (MODE_NO_ZERO_IN_DATE | MODE_NO_ZERO_DATE)) &&
-             mysql_type_to_time_type(to->type()) != MYSQL_TIMESTAMP_TIME))
-        return do_field_temporal;
-      /* Do binary copy */
-    }
-    // Check if identical fields
-    if (from->result_type() == STRING_RESULT)
-    {
-      /*
-        Detect copy from pre 5.0 varbinary to varbinary as of 5.0 and
-        use special copy function that removes trailing spaces and thus
-        repairs data.
-      */
-      if (from->type() == MYSQL_TYPE_VAR_STRING && !from->has_charset() &&
-          to->type() == MYSQL_TYPE_VARCHAR && !to->has_charset())
-        return do_field_varbinary_pre50;
-
-      if (to->real_type() != from->real_type())
-      {
-	if (from->real_type() == MYSQL_TYPE_ENUM ||
-	    from->real_type() == MYSQL_TYPE_SET)
-	  if (to->result_type() != STRING_RESULT)
-	    return do_field_int;		// Convert SET to number
-	return do_field_string;
-      }
-      if (to->real_type() == MYSQL_TYPE_ENUM ||
-	  to->real_type() == MYSQL_TYPE_SET)
-      {
-	if (!to->eq_def(from))
-        {
-          if (from->real_type() == MYSQL_TYPE_ENUM &&
-              to->real_type() == MYSQL_TYPE_ENUM)
-            return do_field_enum;
-          return do_field_string;
-        }
-      }
-      else if (to->charset() != from->charset())
-	return do_field_string;
-      else if (to->real_type() == MYSQL_TYPE_VARCHAR)
-      {
-        if (((Field_varstring*) to)->length_bytes !=
-            ((Field_varstring*) from)->length_bytes)
-          return do_field_string;
-        return (((Field_varstring*) to)->length_bytes == 1 ?
-                (from->charset()->mbmaxlen == 1 ? do_varstring1 :
-                 do_varstring1_mb) :
-                (from->charset()->mbmaxlen == 1 ? do_varstring2 :
-                 do_varstring2_mb));
-      }
-      else if (to_length < from_length)
-	return (from->charset()->mbmaxlen == 1 ?
-                do_cut_string : do_cut_string_complex);
-      else if (to_length > from_length)
-      {
-        if (to->charset() == &my_charset_bin)
-          return do_expand_binary;
-        return do_expand_string;
-      }
-    }
-    else if (to->real_type() != from->real_type() ||
-	     to_length != from_length)
-    {
-      if ((to->real_type() == MYSQL_TYPE_ENUM ||
-           to->real_type() == MYSQL_TYPE_SET) &&
-          from->real_type() == MYSQL_TYPE_NEWDECIMAL)
-        return do_field_decimal;
-      if (to->real_type() == MYSQL_TYPE_DECIMAL ||
-	  to->result_type() == STRING_RESULT)
-	return do_field_string;
-      if (to->result_type() == INT_RESULT)
-	return do_field_int;
-      return do_field_real;
-    }
-    else
-    {
-      if (!to->eq_def(from))
-      {
-	if (to->real_type() == MYSQL_TYPE_DECIMAL)
-	  return do_field_string;
-	if (to->result_type() == INT_RESULT)
-	  return do_field_int;
-	else
-	  return do_field_real;
-      }
-    }
-  }
   /* Identical field types */
-  switch (to_length) {
+  switch (pack_length()) {
   case 1: return do_field_1;
   case 2: return do_field_2;
   case 3: return do_field_3;