MDEV-4511 Assertion `scale <= precision' fails on GROUP BY TIMEDIFF w…

…ith incorrect types

MDEV-6302 Wrong result set when using GROUP BY FROM_UNIXTIME(...)+0
Fixed.

mysql-test/r/func_time.result

@@ -1914,6 +1914,136 @@ SELECT 1 FROM DUAL WHERE MINUTE(TIMEDIFF(NULL, '12:12:12'));
 SELECT 1 FROM DUAL WHERE SECOND(TIMEDIFF(NULL, '12:12:12'));
 1
 #
+# MDEV-4511 Assertion `scale <= precision' fails on GROUP BY TIMEDIFF with incorrect types
+#
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT a FROM t1 GROUP BY TIMEDIFF('2004-06-12',a) * 1;
+a
+2005-05-04
+Warnings:
+Warning	1292	Truncated incorrect time value: '2004-06-12'
+Warning	1292	Truncated incorrect time value: '2004-06-12'
+DROP TABLE t1;
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT a FROM t1 GROUP BY ADDTIME(a,'10')*1;
+a
+2000-02-23
+2005-05-04
+DROP TABLE t1;
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT * FROM t1 GROUP BY SEC_TO_TIME(concat(a,'10'))*1;
+a
+2000-02-23
+2005-05-04
+DROP TABLE t1;
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT * FROM t1 GROUP BY ADDTIME(timestamp('2001-01-01 00:00:00'),CAST(a AS SIGNED)&0xF)*1;
+a
+2005-05-04
+2000-02-23
+DROP TABLE t1;
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT * FROM t1 GROUP BY STR_TO_DATE(a,concat('%Y-%m-%d.%f',if(rand(),'','')))*1;
+a
+2000-02-23
+2005-05-04
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT
+STR_TO_DATE('2001-01-01', '%Y-%m-%d') AS date_only,
+STR_TO_DATE('10:10:10', '%H:%i:%s') AS time_only,
+STR_TO_DATE('10:10:10.123', '%H:%i:%s.%f') AS time_microsecond,
+STR_TO_DATE('2001-01-01 10:10:10', '%Y-%m-%d %H:%i:%s') AS date_time,
+STR_TO_DATE('2001-01-01 10:10:10.123', '%Y-%m-%d %H:%i:%s.%f') AS date_time_microsecond;
+SHOW COLUMNS FROM t1;
+Field	Type	Null	Key	Default	Extra
+date_only	date	YES		NULL	
+time_only	time	YES		NULL	
+time_microsecond	time(6)	YES		NULL	
+date_time	datetime	YES		NULL	
+date_time_microsecond	datetime(6)	YES		NULL	
+DROP TABLE t1;
+CREATE TABLE t1 AS SELECT
+SEC_TO_TIME(1)+0.1,
+SEC_TO_TIME(1.1)+0.1,
+SEC_TO_TIME(1.12)+0.1,
+SEC_TO_TIME(1.123456)+0.1,
+SEC_TO_TIME(1.1234567)+0.1;
+SHOW COLUMNS FROM t1;
+Field	Type	Null	Key	Default	Extra
+SEC_TO_TIME(1)+0.1	decimal(12,1)	YES		NULL	
+SEC_TO_TIME(1.1)+0.1	decimal(13,1)	YES		NULL	
+SEC_TO_TIME(1.12)+0.1	decimal(14,2)	YES		NULL	
+SEC_TO_TIME(1.123456)+0.1	decimal(18,6)	YES		NULL	
+SEC_TO_TIME(1.1234567)+0.1	decimal(18,6)	YES		NULL	
+DROP TABLE t1;
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT * FROM t1 GROUP BY FROM_UNIXTIME(concat(a,'10'))*1;
+a
+2000-02-23
+2005-05-04
+SELECT * FROM t1 GROUP BY (-FROM_UNIXTIME(concat(a,'10')))*1;
+a
+2005-05-04
+2000-02-23
+SELECT * FROM t1 GROUP BY (-FROM_UNIXTIME(concat(a,'10')));
+a
+2005-05-04
+2000-02-23
+SELECT * FROM t1 GROUP BY ABS(FROM_UNIXTIME(concat(a,'10')));
+a
+2000-02-23
+2005-05-04
+SELECT * FROM t1 GROUP BY @a:=(FROM_UNIXTIME(concat(a,'10'))*1);
+a
+2000-02-23
+2005-05-04
+DROP TABLE t1;
+#
+# MDEV-6302 Wrong result set when using GROUP BY FROM_UNIXTIME(...)+0
+#
+CREATE TABLE t1 (a DATE);
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT a, FROM_UNIXTIME(CONCAT(a,'10')) AS f1, FROM_UNIXTIME(CONCAT(a,'10'))+0 AS f2 FROM t1;
+a	f1	f2
+2005-05-04	1970-01-01 03:33:25	19700101033325.000000
+2000-02-23	1970-01-01 03:33:20	19700101033320.000000
+SELECT * FROM t1 GROUP BY FROM_UNIXTIME(CONCAT(a,'10'))+0;
+a
+2000-02-23
+2005-05-04
+DROP TABLE t1;
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT * FROM t1 GROUP BY FROM_UNIXTIME(concat(a,'10'))/1;
+a
+2000-02-23
+2005-05-04
+DROP TABLE t1;
+CREATE TABLE t1 (a DATE);
+INSERT INTO t1 VALUES ('2005-05-04');
+SELECT CONCAT(FROM_UNIXTIME(CONCAT(a,'10')) MOD FROM_UNIXTIME(CONCAT(a,'10'))) AS f2 FROM t1;
+f2
+0.000000
+SELECT CHAR_LENGTH(CONCAT(FROM_UNIXTIME(CONCAT(a,'10')) MOD FROM_UNIXTIME(CONCAT(a,'10')))) AS f2 FROM t1;
+f2
+8
+CREATE TABLE t2 AS SELECT CONCAT(FROM_UNIXTIME(CONCAT(a,'10')) MOD FROM_UNIXTIME(CONCAT(a,'10'))) AS f2 FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `f2` varbinary(26) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT * FROM t2;
+f2
+0.000000
+DROP TABLE t1,t2;
+#
 # MDEV-4635 Crash in UNIX_TIMESTAMP(STR_TO_DATE('2020','%Y'))
 #
 SET TIME_ZONE='+02:00';

mysql-test/r/type_decimal.result

@@ -798,10 +798,10 @@ ROUND(qty,3)	dps	ROUND(qty,dps)
 DROP TABLE t1;
 SELECT 1 % .123456789123456789123456789123456789123456789123456789123456789123456789123456789 AS '%';
 %
-0.012345687012345687012345687012345687012345687012345687012345687012345687000000000
+0.012345687012345687012345687012
 SELECT MOD(1, .123456789123456789123456789123456789123456789123456789123456789123456789123456789) AS 'MOD()';
 MOD()
-0.012345687012345687012345687012345687012345687012345687012345687012345687000000000
+0.012345687012345687012345687012
 create table t1 (f1 decimal(6,6),f2 decimal(6,6) zerofill);
 insert into t1 values (-0.123456,0.123456);
 select group_concat(f1),group_concat(f2) from t1;

mysql-test/r/type_newdecimal.result

@@ -703,7 +703,7 @@ select .7777777777777777777777777777777777777 *
 777777777777777777.777777777777777777700000000000
 select .7777777777777777777777777777777777777 - 0.1;
 .7777777777777777777777777777777777777 - 0.1
-0.6777777777777777777777777777777777777
+0.677777777777777777777777777778
 select .343434343434343434 + .343434343434343434;
 .343434343434343434 + .343434343434343434
 0.686868686868686868
@@ -1845,7 +1845,7 @@ Warnings:
 Note	1265	Data truncated for column 'c1' at row 3
 DESC t2;
 Field	Type	Null	Key	Default	Extra
-c1	decimal(32,30)	YES		NULL	
+c1	decimal(33,30)	YES		NULL	
 DROP TABLE t1,t2;
 CREATE TABLE t1 (a DECIMAL(30,30));
 INSERT INTO t1 VALUES (0.1),(0.2),(0.3);
@@ -1856,7 +1856,7 @@ Note	1265	Data truncated for column 'c1' at row 2
 Note	1265	Data truncated for column 'c1' at row 3
 DESC t2;
 Field	Type	Null	Key	Default	Extra
-c1	decimal(34,0)	YES		NULL	
+c1	decimal(33,30)	YES		NULL	
 DROP TABLE t1,t2;
 CREATE TABLE t1 (a DECIMAL(30,30));
 INSERT INTO t1 VALUES (0.1),(0.2),(0.3);

mysql-test/t/func_time.test

@@ -1156,6 +1156,86 @@ SELECT 1 FROM DUAL WHERE MINUTE(TIMEDIFF(NULL, '12:12:12'));
 SELECT 1 FROM DUAL WHERE SECOND(TIMEDIFF(NULL, '12:12:12'));
 
 
+--echo #
+--echo # MDEV-4511 Assertion `scale <= precision' fails on GROUP BY TIMEDIFF with incorrect types
+--echo #
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT a FROM t1 GROUP BY TIMEDIFF('2004-06-12',a) * 1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT a FROM t1 GROUP BY ADDTIME(a,'10')*1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT * FROM t1 GROUP BY SEC_TO_TIME(concat(a,'10'))*1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT * FROM t1 GROUP BY ADDTIME(timestamp('2001-01-01 00:00:00'),CAST(a AS SIGNED)&0xF)*1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT * FROM t1 GROUP BY STR_TO_DATE(a,concat('%Y-%m-%d.%f',if(rand(),'','')))*1;
+DROP TABLE t1;
+
+CREATE TABLE t1 AS SELECT
+  STR_TO_DATE('2001-01-01', '%Y-%m-%d') AS date_only,
+  STR_TO_DATE('10:10:10', '%H:%i:%s') AS time_only,
+  STR_TO_DATE('10:10:10.123', '%H:%i:%s.%f') AS time_microsecond,
+  STR_TO_DATE('2001-01-01 10:10:10', '%Y-%m-%d %H:%i:%s') AS date_time,
+  STR_TO_DATE('2001-01-01 10:10:10.123', '%Y-%m-%d %H:%i:%s.%f') AS date_time_microsecond;
+SHOW COLUMNS FROM t1;
+DROP TABLE t1;
+
+CREATE TABLE t1 AS SELECT
+  SEC_TO_TIME(1)+0.1,
+  SEC_TO_TIME(1.1)+0.1,
+  SEC_TO_TIME(1.12)+0.1,
+  SEC_TO_TIME(1.123456)+0.1,
+  SEC_TO_TIME(1.1234567)+0.1;
+SHOW COLUMNS FROM t1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT * FROM t1 GROUP BY FROM_UNIXTIME(concat(a,'10'))*1;
+SELECT * FROM t1 GROUP BY (-FROM_UNIXTIME(concat(a,'10')))*1;
+SELECT * FROM t1 GROUP BY (-FROM_UNIXTIME(concat(a,'10')));
+SELECT * FROM t1 GROUP BY ABS(FROM_UNIXTIME(concat(a,'10')));
+SELECT * FROM t1 GROUP BY @a:=(FROM_UNIXTIME(concat(a,'10'))*1);
+
+DROP TABLE t1;
+
+
+--echo #
+--echo # MDEV-6302 Wrong result set when using GROUP BY FROM_UNIXTIME(...)+0
+--echo #
+CREATE TABLE t1 (a DATE);
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT a, FROM_UNIXTIME(CONCAT(a,'10')) AS f1, FROM_UNIXTIME(CONCAT(a,'10'))+0 AS f2 FROM t1;
+SELECT * FROM t1 GROUP BY FROM_UNIXTIME(CONCAT(a,'10'))+0;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
+SELECT * FROM t1 GROUP BY FROM_UNIXTIME(concat(a,'10'))/1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (a DATE);
+INSERT INTO t1 VALUES ('2005-05-04');
+SELECT CONCAT(FROM_UNIXTIME(CONCAT(a,'10')) MOD FROM_UNIXTIME(CONCAT(a,'10'))) AS f2 FROM t1; 
+SELECT CHAR_LENGTH(CONCAT(FROM_UNIXTIME(CONCAT(a,'10')) MOD FROM_UNIXTIME(CONCAT(a,'10')))) AS f2 FROM t1; 
+CREATE TABLE t2 AS SELECT CONCAT(FROM_UNIXTIME(CONCAT(a,'10')) MOD FROM_UNIXTIME(CONCAT(a,'10'))) AS f2 FROM t1;
+SHOW CREATE TABLE t2;
+SELECT * FROM t2;
+DROP TABLE t1,t2;
+
 --echo #
 --echo # MDEV-4635 Crash in UNIX_TIMESTAMP(STR_TO_DATE('2020','%Y'))
 --echo #

sql/field.h

@@ -65,6 +65,29 @@ inline bool is_temporal_type(enum_field_types type)
   return mysql_type_to_time_type(type) != MYSQL_TIMESTAMP_ERROR;
 }
 
+
+/**
+  Tests if field type is temporal and has time part,
+  i.e. represents TIME, DATETIME or TIMESTAMP types in SQL.
+
+  @param type    Field type, as returned by field->type().
+  @retval true   If field type is temporal type with time part.
+  @retval false  If field type is not temporal type with time part.
+*/
+inline bool is_temporal_type_with_time(enum_field_types type)
+{
+  switch (type)
+  {
+  case MYSQL_TYPE_TIME:
+  case MYSQL_TYPE_DATETIME:
+  case MYSQL_TYPE_TIMESTAMP:
+    return true;
+  default:
+    return false;
+  }
+}
+
+
 /*
   Virtual_column_info is the class to contain additional
   characteristics that is specific for a virtual/computed

sql/item.h

@@ -909,9 +909,47 @@ class Item {
   virtual cond_result eq_cmp_result() const { return COND_OK; }
   inline uint float_length(uint decimals_par) const
   { return decimals != NOT_FIXED_DEC ? (DBL_DIG+2+decimals_par) : DBL_DIG+8;}
+  /* Returns total number of decimal digits */
   virtual uint decimal_precision() const;
+  /* Returns the number of integer part digits only */
   inline int decimal_int_part() const
   { return my_decimal_int_part(decimal_precision(), decimals); }
+  /*
+    Returns the number of fractional digits only.
+    NOT_FIXED_DEC is replaced to the maximum possible number
+    of fractional digits, taking into account the data type.
+  */
+  uint decimal_scale() const
+  {
+    return decimals < NOT_FIXED_DEC ? decimals :
+           is_temporal_type_with_time(field_type()) ?
+           TIME_SECOND_PART_DIGITS :
+           min(max_length, DECIMAL_MAX_SCALE);
+  }
+  /*
+    Returns how many digits a divisor adds into a division result.
+    This is important when the integer part of the divisor can be 0.
+    In this  example:
+      SELECT 1 / 0.000001; -> 1000000.0000
+    the divisor adds 5 digits into the result precision.
+
+    Currently this method only replaces NOT_FIXED_DEC to
+    TIME_SECOND_PART_DIGITS for temporal data types.
+    This method can be made virtual, to create more efficient (smaller)
+    data types for division results.
+    For example, in
+      SELECT 1/1.000001;
+    the divisor could provide no additional precision into the result,
+    so could any other items that are know to return a result
+    with non-zero integer part.
+  */
+  uint divisor_precision_increment() const
+  {
+    return decimals <  NOT_FIXED_DEC ? decimals :
+           is_temporal_type_with_time(field_type()) ?
+           TIME_SECOND_PART_DIGITS :
+           decimals;
+  }
   /**
     TIME or DATETIME precision of the item: 0..6
   */