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

null_value was not properly reset when setting parameter value

Author: montywi

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);