Tests for MDEV-18667 ASAN heap-use-after-free in make_date_time /...

Tests for MDEV-18667 ASAN heap-use-after-free in make_date_time / Arg_comparator::compare_string / Item_func_nullif::compare

The patch for MDEV-14926 fixed MDEV-18667 as well. Adding tests only.

mysql-test/r/func_time.result

@@ -3436,5 +3436,13 @@ f
 4
 DROP TABLE t1;
 #
+# MDEV-18667 ASAN heap-use-after-free in make_date_time / Arg_comparator::compare_string / Item_func_nullif::compare
+#
+SELECT NULLIF('foo', FROM_UNIXTIME('2012-12-12 12:12:12', TRIM(0)));
+NULLIF('foo', FROM_UNIXTIME('2012-12-12 12:12:12', TRIM(0)))
+foo
+Warnings:
+Warning	1292	Truncated incorrect DECIMAL value: '2012-12-12 12:12:12'
+#
 # End of 10.1 tests
 #

mysql-test/t/func_time.test

@@ -1923,6 +1923,11 @@ INSERT INTO t1 VALUES ('1900-01-01');
 SELECT LENGTH( DATE_FORMAT( d, BINARY DATABASE() ) ) AS f FROM t1 GROUP BY d;
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-18667 ASAN heap-use-after-free in make_date_time / Arg_comparator::compare_string / Item_func_nullif::compare
+--echo #
+
+SELECT NULLIF('foo', FROM_UNIXTIME('2012-12-12 12:12:12', TRIM(0)));
 
 --echo #
 --echo # End of 10.1 tests