MDEV-17015 Assertion `m_year <= 9999' failed in Year::Year upon bad argument to MAKEDATE

mysql-test/main/type_year.result

@@ -554,5 +554,11 @@ MIN(a)	MAX(a)
 70	69
 DROP TABLE t1;
 #
+# MDEV-17015 Assertion `m_year <= 9999' failed in Year::Year upon bad argument to MAKEDATE
+#
+SELECT MAKEDATE(18446744073709551615, 1);
+MAKEDATE(18446744073709551615, 1)
+NULL
+#
 # End of 10.4 tests
 #

mysql-test/main/type_year.test

@@ -294,6 +294,10 @@ SELECT a, CAST(a AS DATE), CAST(COALESCE(a) AS DATE) FROM t1;
 SELECT MIN(a), MAX(a) FROM t1;
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-17015 Assertion `m_year <= 9999' failed in Year::Year upon bad argument to MAKEDATE
+--echo #
+SELECT MAKEDATE(18446744073709551615, 1);
 
 --echo #
 --echo # End of 10.4 tests

sql/sql_type.cc

@@ -323,8 +323,8 @@ VSec6::VSec6(Item *item, const char *type_str, ulonglong limit)
 
 Year::Year(longlong value, bool unsigned_flag, uint length)
 {
-  if ((m_truncated= (value < 0 && !unsigned_flag)))
-    m_year= 0;
+  if ((m_truncated= (value < 0))) // Negative or huge unsigned
+    m_year= unsigned_flag ? 9999 : 0;
   else if (value > 9999)
   {
     m_truncated= true;