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

null_value was not properly reset when setting parameter value

sql/item.cc

@@ -3781,6 +3781,7 @@ void Item_param::set_int(longlong i, uint32 max_length_arg)
   max_length= max_length_arg;
   decimals= 0;
   maybe_null= 0;
+  null_value= 0;
   fix_type(Item::INT_ITEM);
   DBUG_VOID_RETURN;
 }
@@ -3795,6 +3796,7 @@ void Item_param::set_double(double d)
   max_length= DBL_DIG + 8;
   decimals= NOT_FIXED_DEC;
   maybe_null= 0;
+  null_value= 0;
   fix_type(Item::REAL_ITEM);
   DBUG_VOID_RETURN;
 }
@@ -3827,6 +3829,7 @@ void Item_param::set_decimal(const char *str, ulong length)
     my_decimal_precision_to_length_no_truncation(value.m_decimal.precision(),
                                                  decimals, unsigned_flag);
   maybe_null= 0;
+  null_value= 0;
   fix_type(Item::DECIMAL_ITEM);
   DBUG_VOID_RETURN;
 }
@@ -3843,6 +3846,7 @@ 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);
+  null_value= 0;
   fix_type(Item::DECIMAL_ITEM);
 }
 
@@ -3862,6 +3866,7 @@ void Item_param::set_time(const MYSQL_TIME *tm,
 {
   DBUG_ASSERT(value.type_handler()->cmp_type() == TIME_RESULT);
   value.time= *tm;
+  null_value= 0;
   fix_temporal(max_length_arg, decimals_arg);
 }
 
@@ -3896,6 +3901,7 @@ void Item_param::set_time(MYSQL_TIME *tm, timestamp_type time_type,
     set_zero_time(&value.time, MYSQL_TIMESTAMP_ERROR);
   }
   maybe_null= 0;
+  null_value= 0;
   fix_temporal(max_length_arg,
                tm->second_part > 0 ? TIME_SECOND_PART_DIGITS : 0);
   DBUG_VOID_RETURN;
@@ -3932,6 +3938,7 @@ bool Item_param::set_str(const char *str, ulong length,
   collation.set(tocs, DERIVATION_COERCIBLE);
   max_length= length;
   maybe_null= 0;
+  null_value= 0;
   /* max_length and decimals are set after charset conversion */
   /* sic: str may be not null-terminated, don't add DBUG_PRINT here */
   fix_type(Item::STRING_ITEM);
@@ -3967,6 +3974,7 @@ bool Item_param::set_longdata(const char *str, ulong length)
     DBUG_RETURN(TRUE);
   state= LONG_DATA_VALUE;
   maybe_null= 0;
+  null_value= 0;
   fix_type(Item::STRING_ITEM);
 
   DBUG_RETURN(FALSE);