MDEV-19301 Assertion `!is_valid_datetime() ||...

MDEV-19301 Assertion `!is_valid_datetime() || fraction_remainder(((item->decimals) < (6) ? (item->decimals) : (6))) == 0' failed in Datetime_truncation_not_needed::Datetime_truncation_not_needed

mysql-test/main/type_date.result

@@ -1025,5 +1025,20 @@ INSERT INTO t1 SELECT * FROM t2;
 DROP TABLE t1,t2;
 SET sql_mode=DEFAULT;
 #
+# MDEV-19301 Assertion `!is_valid_datetime() || fraction_remainder(((item->decimals) < (6) ? (item->decimals) : (6))) == 0' failed in Datetime_truncation_not_needed::Datetime_truncation_not_needed
+#
+SELECT NULLIF(CAST(1012.5 AS DATE), 1);
+NULLIF(CAST(1012.5 AS DATE), 1)
+2000-10-12
+Warnings:
+Note	1292	Truncated incorrect date value: '1012.5'
+Warning	1292	Truncated incorrect datetime value: '1'
+Note	1292	Truncated incorrect date value: '1012.5'
+SELECT CAST(1012.5 AS DATE) * 1.0;
+CAST(1012.5 AS DATE) * 1.0
+20001012.0
+Warnings:
+Note	1292	Truncated incorrect date value: '1012.5'
+#
 # End of 10.4 tests
 #

mysql-test/main/type_date.test

@@ -691,6 +691,14 @@ DROP TABLE t1,t2;
 SET sql_mode=DEFAULT;
 
 
+--echo #
+--echo # MDEV-19301 Assertion `!is_valid_datetime() || fraction_remainder(((item->decimals) < (6) ? (item->decimals) : (6))) == 0' failed in Datetime_truncation_not_needed::Datetime_truncation_not_needed
+--echo #
+
+SELECT NULLIF(CAST(1012.5 AS DATE), 1);
+SELECT CAST(1012.5 AS DATE) * 1.0;
+
+
 --echo #
 --echo # End of 10.4 tests
 --echo #

sql-common/my_time.c

@@ -1728,7 +1728,11 @@ longlong number_to_datetime_or_date(longlong nr, ulong sec_part,
       !check_date(time_res, nr || sec_part, flags, was_cut))
   {
     if (time_res->time_type == MYSQL_TIMESTAMP_DATE && sec_part != 0)
-       *was_cut= MYSQL_TIME_NOTE_TRUNCATED;
+    {
+      /* Date format, but with fractional digits, e.g. 20010203.5 */
+      *was_cut= MYSQL_TIME_NOTE_TRUNCATED;
+      time_res->second_part= 0;
+    }
     return nr;
   }