MDEV-19699 Server crashes in Item_null_result::field_type upon SELECT with ROLLUP on constant table

Also fixes:

MDEV-20431 GREATEST(int_col,date_col) returns wrong results in a view

mysql-test/r/type_date.result

@@ -863,12 +863,14 @@ SELECT group_concat(d1/(CASE 'b' WHEN 'j' THEN 'c' END))
 FROM v1 GROUP BY greatest(pk, 0, d2);
 group_concat(d1/(CASE 'b' WHEN 'j' THEN 'c' END))
 NULL
+NULL
 Warnings:
 Warning	1292	Incorrect datetime value: '1' for column 'pk' at row 1
 Warning	1292	Incorrect datetime value: '2' for column 'pk' at row 1
 Warning	1292	Incorrect datetime value: '1' for column 'pk' at row 1
 Warning	1292	Incorrect datetime value: '1' for column 'pk' at row 1
 Warning	1292	Incorrect datetime value: '2' for column 'pk' at row 2
+Warning	1292	Incorrect datetime value: '2' for column 'pk' at row 2
 CREATE TABLE t2 AS SELECT greatest(pk, 0, d2) AS c1 FROM t1 LIMIT 0;
 SHOW CREATE TABLE t2;
 Table	Create Table
@@ -879,5 +881,36 @@ DROP TABLE t2;
 DROP VIEW v1;
 DROP TABLE t1;
 #
+# MDEV-19699 Server crashes in Item_null_result::field_type upon SELECT with ROLLUP on constant table
+#
+CREATE TABLE t1 (d DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('1999-11-04');
+SELECT d FROM t1 GROUP BY d WITH ROLLUP HAVING d > '1990-01-01';
+d
+1999-11-04
+DROP TABLE t1;
+#
+# MDEV-20431 GREATEST(int_col,date_col) returns wrong results in a view
+#
+CREATE TABLE t1 (pk INT NOT NULL, d DATE NOT NULL);
+CREATE VIEW v1 AS SELECT * FROM t1;
+INSERT INTO t1 VALUES (1,'2018-06-22'),(2,'2018-07-11');
+SELECT GREATEST(pk, d) FROM t1;
+GREATEST(pk, d)
+2018-06-22
+2018-07-11
+Warnings:
+Warning	1292	Incorrect datetime value: '1' for column 'pk' at row 1
+Warning	1292	Incorrect datetime value: '2' for column 'pk' at row 2
+SELECT GREATEST(pk, d) FROM v1;
+GREATEST(pk, d)
+2018-06-22
+2018-07-11
+Warnings:
+Warning	1292	Incorrect datetime value: '1' for column 'pk' at row 1
+Warning	1292	Incorrect datetime value: '2' for column 'pk' at row 2
+DROP VIEW v1;
+DROP TABLE t1;
+#
 # End of 10.1 tests
 #

mysql-test/r/type_datetime.result

@@ -1167,5 +1167,36 @@ INSERT INTO t2 SELECT * FROM t1;
 DROP TABLE t1, t2;
 SET SQL_MODE=DEFAULT;
 #
+# MDEV-19699 Server crashes in Item_null_result::field_type upon SELECT with ROLLUP on constant table
+#
+CREATE TABLE t1 (d DATETIME) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('1999-11-04');
+SELECT d FROM t1 GROUP BY d WITH ROLLUP HAVING d > '1990-01-01';
+d
+1999-11-04 00:00:00
+DROP TABLE t1;
+#
+# MDEV-20431 GREATEST(int_col,date_col) returns wrong results in a view
+#
+CREATE TABLE t1 (pk INT NOT NULL, d DATETIME NOT NULL);
+CREATE VIEW v1 AS SELECT * FROM t1;
+INSERT INTO t1 VALUES (1,'2018-06-22 00:00:00'),(2,'2018-07-11 00:00:00');
+SELECT GREATEST(pk, d) FROM t1;
+GREATEST(pk, d)
+2018-06-22 00:00:00
+2018-07-11 00:00:00
+Warnings:
+Warning	1292	Incorrect datetime value: '1' for column 'pk' at row 1
+Warning	1292	Incorrect datetime value: '2' for column 'pk' at row 2
+SELECT GREATEST(pk, d) FROM v1;
+GREATEST(pk, d)
+2018-06-22 00:00:00
+2018-07-11 00:00:00
+Warnings:
+Warning	1292	Incorrect datetime value: '1' for column 'pk' at row 1
+Warning	1292	Incorrect datetime value: '2' for column 'pk' at row 2
+DROP VIEW v1;
+DROP TABLE t1;
+#
 # End of 10.1 tests
 #

mysql-test/t/type_date.test

@@ -600,6 +600,30 @@ DROP TABLE t2;
 DROP VIEW v1;
 DROP TABLE t1;
 
+
+--echo #
+--echo # MDEV-19699 Server crashes in Item_null_result::field_type upon SELECT with ROLLUP on constant table
+--echo #
+
+CREATE TABLE t1 (d DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('1999-11-04');
+SELECT d FROM t1 GROUP BY d WITH ROLLUP HAVING d > '1990-01-01';
+DROP TABLE t1;
+
+
+--echo #
+--echo # MDEV-20431 GREATEST(int_col,date_col) returns wrong results in a view
+--echo #
+
+CREATE TABLE t1 (pk INT NOT NULL, d DATE NOT NULL);
+CREATE VIEW v1 AS SELECT * FROM t1;
+INSERT INTO t1 VALUES (1,'2018-06-22'),(2,'2018-07-11');
+SELECT GREATEST(pk, d) FROM t1;
+SELECT GREATEST(pk, d) FROM v1;
+DROP VIEW v1;
+DROP TABLE t1;
+
+
 --echo #
 --echo # End of 10.1 tests
 --echo #

mysql-test/t/type_datetime.test

@@ -724,6 +724,29 @@ DROP TABLE t1, t2;
 SET SQL_MODE=DEFAULT;
 
 
+--echo #
+--echo # MDEV-19699 Server crashes in Item_null_result::field_type upon SELECT with ROLLUP on constant table
+--echo #
+
+CREATE TABLE t1 (d DATETIME) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('1999-11-04');
+SELECT d FROM t1 GROUP BY d WITH ROLLUP HAVING d > '1990-01-01';
+DROP TABLE t1;
+
+
+--echo #
+--echo # MDEV-20431 GREATEST(int_col,date_col) returns wrong results in a view
+--echo #
+
+CREATE TABLE t1 (pk INT NOT NULL, d DATETIME NOT NULL);
+CREATE VIEW v1 AS SELECT * FROM t1;
+INSERT INTO t1 VALUES (1,'2018-06-22 00:00:00'),(2,'2018-07-11 00:00:00');
+SELECT GREATEST(pk, d) FROM t1;
+SELECT GREATEST(pk, d) FROM v1;
+DROP VIEW v1;
+DROP TABLE t1;
+
+
 --echo #
 --echo # End of 10.1 tests
 --echo #

sql/item.cc

@@ -3131,6 +3131,20 @@ my_decimal *Item_null::val_decimal(my_decimal *decimal_value)
 }
 
 
+longlong Item_null::val_datetime_packed()
+{
+  null_value= true;
+  return 0;
+}
+
+
+longlong Item_null::val_time_packed()
+{
+  null_value= true;
+  return 0;
+}
+
+
 bool Item_null::get_date(MYSQL_TIME *ltime, ulonglong fuzzydate)
 {
   // following assert is redundant, because fixed=1 assigned in constructor
@@ -7296,6 +7310,24 @@ bool Item_ref::get_date(MYSQL_TIME *ltime,ulonglong fuzzydate)
 }
 
 
+longlong Item_ref::val_datetime_packed()
+{
+  DBUG_ASSERT(fixed);
+  longlong tmp= (*ref)->val_datetime_packed();
+  null_value= (*ref)->null_value;
+  return tmp;
+}
+
+
+longlong Item_ref::val_time_packed()
+{
+  DBUG_ASSERT(fixed);
+  longlong tmp= (*ref)->val_time_packed();
+  null_value= (*ref)->null_value;
+  return tmp;
+}
+
+
 my_decimal *Item_ref::val_decimal(my_decimal *decimal_value)
 {
   my_decimal *val= (*ref)->val_decimal_result(decimal_value);

sql/item.h

@@ -2627,6 +2627,8 @@ class Item_null :public Item_basic_constant
   String *val_str(String *str);
   my_decimal *val_decimal(my_decimal *);
   bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate);
+  longlong val_datetime_packed();
+  longlong val_time_packed();
   int save_in_field(Field *field, bool no_conversions);
   int save_safe_in_field(Field *field);
   bool send(Protocol *protocol, String *str);
@@ -3971,6 +3973,8 @@ class Item_ref :public Item_ident
   String *val_str(String* tmp);
   bool is_null();
   bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate);
+  longlong val_datetime_packed();
+  longlong val_time_packed();
   double val_result();
   longlong val_int_result();
   String *str_result(String* tmp);