Merge 10.1 into 10.2

For MDEV-15955, the fix in create_tmp_field_from_item() would cause a
compilation error. After a discussion with Alexander Barkov, the fix
was omitted and only the test case was kept.

In 10.3 and later, MDEV-15955 is fixed properly by overriding
create_tmp_field() in Item_func_user_var.

mysql-test/suite/wsrep/t/mysql_tzinfo_to_sql_symlink_skip.test

@@ -0,0 +1,40 @@
+--source include/have_wsrep.inc
+--source include/have_symlink.inc
+--source include/not_windows.inc
+
+--echo #
+--echo # MDEV-5226 mysql_tzinfo_to_sql errors with tzdata 2013f and above
+--echo #
+
+--exec mkdir $MYSQLTEST_VARDIR/zoneinfo
+--exec ln -s $MYSQLTEST_VARDIR/zoneinfo $MYSQLTEST_VARDIR/zoneinfo/posix
+--copy_file std_data/zoneinfo/GMT $MYSQLTEST_VARDIR/zoneinfo/GMT
+--copy_file std_data/words.dat $MYSQLTEST_VARDIR/zoneinfo/garbage
+--copy_file std_data/words.dat $MYSQLTEST_VARDIR/zoneinfo/ignored.tab
+
+--echo # Verbose run
+--replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
+--exec $MYSQL_TZINFO_TO_SQL --verbose --skip-write-binlog $MYSQLTEST_VARDIR/zoneinfo 2>&1
+
+--echo # Silent run
+--replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
+--exec $MYSQL_TZINFO_TO_SQL --skip-write-binlog $MYSQLTEST_VARDIR/zoneinfo 2>&1
+
+--echo #
+--echo # Testing with explicit timezonefile
+--echo #
+
+--replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
+--exec $MYSQL_TZINFO_TO_SQL --skip-write-binlog $MYSQLTEST_VARDIR/zoneinfo/GMT XXX 2>&1
+
+--echo #
+--echo # Testing --leap
+--echo #
+
+--exec $MYSQL_TZINFO_TO_SQL --leap --skip-write-binlog $MYSQLTEST_VARDIR/zoneinfo/GMT 2>&1
+
+#
+# Cleanup
+#
+
+--exec rm -rf $MYSQLTEST_VARDIR/zoneinfo