MDEV-15133: array bound (bulk) parameters of NULL propagate on next rows

Setting non_null value drops null_value flag.
Part 2 of 3.
Part 1 was 10.2 fix.
Part 3 is test for Connector C.

mysql-test/r/ps.result

@@ -1738,7 +1738,7 @@ execute stmt using @a;
 show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `?` decimal(2,1) DEFAULT NULL
+  `?` decimal(2,1) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
 drop table if exists t1;
@@ -4432,7 +4432,7 @@ EXECUTE stmt USING 10.123;
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `c1` decimal(5,3) DEFAULT NULL
+  `c1` decimal(5,3) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 EXECUTE stmt USING 10.123e0;
@@ -4446,49 +4446,49 @@ EXECUTE stmt USING CURRENT_DATE;
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `c1` date DEFAULT NULL
+  `c1` date NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 EXECUTE stmt USING CURRENT_TIMESTAMP;
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `c1` datetime DEFAULT NULL
+  `c1` datetime NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 EXECUTE stmt USING CURRENT_TIMESTAMP(3);
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `c1` datetime(3) DEFAULT NULL
+  `c1` datetime(3) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 EXECUTE stmt USING CURRENT_TIMESTAMP(6);
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `c1` datetime(6) DEFAULT NULL
+  `c1` datetime(6) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 EXECUTE stmt USING CURRENT_TIME;
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `c1` time DEFAULT NULL
+  `c1` time NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 EXECUTE stmt USING CURRENT_TIME(3);
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `c1` time(3) DEFAULT NULL
+  `c1` time(3) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 EXECUTE stmt USING CURRENT_TIME(6);
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `c1` time(6) DEFAULT NULL
+  `c1` time(6) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 DEALLOCATE PREPARE stmt;
@@ -4633,7 +4633,7 @@ SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` bigint(20) NOT NULL,
-  `b` decimal(3,1) DEFAULT NULL,
+  `b` decimal(3,1) NOT NULL,
   `c` double NOT NULL,
   `d` tinytext NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
@@ -4645,7 +4645,7 @@ SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(2) NOT NULL,
-  `b` decimal(3,1) DEFAULT NULL,
+  `b` decimal(3,1) NOT NULL,
   `c` double NOT NULL,
   `d` varchar(3) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
@@ -4660,11 +4660,11 @@ TIMESTAMP'2001-01-01 10:20:30.123';
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `t1` time DEFAULT NULL,
-  `t2` time(3) DEFAULT NULL,
-  `d1` date DEFAULT NULL,
-  `dt1` datetime DEFAULT NULL,
-  `dt2` datetime(3) DEFAULT NULL
+  `t1` time NOT NULL,
+  `t2` time(3) NOT NULL,
+  `d1` date NOT NULL,
+  `dt1` datetime NOT NULL,
+  `dt2` datetime(3) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 #

sql/item.cc

@@ -3757,7 +3757,10 @@ Item_param::Item_param(THD *thd, const LEX_CSTRING *name_arg,
 void Item_param::set_null()
 {
   DBUG_ENTER("Item_param::set_null");
-  /* These are cleared after each execution by reset() method */
+  /*
+    These are cleared after each execution by reset() method or by setting
+    other value.
+  */
   null_value= 1;
   /* 
     Because of NULL and string values we need to set max_length for each new
@@ -3846,6 +3849,7 @@ void Item_param::set_decimal(const my_decimal *dv, bool unsigned_arg)
   unsigned_flag= unsigned_arg;
   max_length= my_decimal_precision_to_length(value.m_decimal.intg + decimals,
                                              decimals, unsigned_flag);
+  maybe_null= 0;
   null_value= 0;
   fix_type(Item::DECIMAL_ITEM);
 }
@@ -3857,6 +3861,8 @@ void Item_param::fix_temporal(uint32 max_length_arg, uint decimals_arg)
   collation.set_numeric();
   max_length= max_length_arg;
   decimals= decimals_arg;
+  maybe_null= 0;
+  null_value= 0;
   fix_type(Item::DATE_ITEM);
 }
 
@@ -3866,6 +3872,7 @@ void Item_param::set_time(const MYSQL_TIME *tm,
 {
   DBUG_ASSERT(value.type_handler()->cmp_type() == TIME_RESULT);
   value.time= *tm;
+  maybe_null= 0;
   null_value= 0;
   fix_temporal(max_length_arg, decimals_arg);
 }
@@ -4634,7 +4641,9 @@ Item_param::set_value(THD *thd, sp_rcontext *ctx, Item **it)
     set_null();
     return false;
   }
-  return null_value= false;
+  /* It is wrapper => other set_* shoud set null_value */
+  DBUG_ASSERT(null_value == false);
+  return false;
 }