MDEV-18072 Assertion `is_null() == item->null_value || conv' failed in...

MDEV-18072 Assertion `is_null() == item->null_value || conv' failed in Timestamp_or_zero_datetime_native_null::Timestamp_or_zero_datetime_native_null upon query with GROUP BY

mysql-test/main/type_time.result

@@ -2177,5 +2177,14 @@ ERROR 22007: Incorrect time value: '0000-00-00 00:00:00' for column `test`.`t1`.
 SET sql_mode=DEFAULT;
 DROP TABLE t1;
 #
+# MDEV-18070 Assertion `nanoseconds <= 1000000000' failed in Temporal::add_nanoseconds_ssff with TIME_ROUND_FRACTIONAL
+#
+CREATE TABLE t1 (t TIME);
+SET SQL_MODE= 'TIME_ROUND_FRACTIONAL';
+INSERT INTO t1 VALUES (3e19);
+Warnings:
+Warning	1264	Out of range value for column 't' at row 1
+DROP TABLE t1;
+#
 # End of 10.4 tests
 #

mysql-test/main/type_time.test

@@ -1420,6 +1420,15 @@ INSERT INTO t1 VALUES ('0000-00-00 00:00:00'),('0000-00-00 00:00:00');
 SET sql_mode=DEFAULT;
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-18070 Assertion `nanoseconds <= 1000000000' failed in Temporal::add_nanoseconds_ssff with TIME_ROUND_FRACTIONAL
+--echo #
+
+CREATE TABLE t1 (t TIME);
+SET SQL_MODE= 'TIME_ROUND_FRACTIONAL';
+INSERT INTO t1 VALUES (3e19);
+DROP TABLE t1;
+
 
 --echo #
 --echo # End of 10.4 tests

sql/sql_type.cc

@@ -331,6 +331,7 @@ void Sec6::make_from_double(double nr, ulong *nanoseconds)
   {
     m_sec= LONGLONG_MAX;
     m_usec= 0;
+    *nanoseconds= 0;
   }
   else
   {