MDEV-29736 mysqldump sets system_versioning_insert_history=1 twice and doesn't...

MDEV-29736 mysqldump sets system_versioning_insert_history=1 twice and doesn't restore previous value

client/mysqldump.c

@@ -4329,7 +4329,7 @@ static void dump_table(const char *table, const char *db, const uchar *hash_key,
 
     if (versioned && !opt_xml && opt_dump_history)
     {
-      fprintf(md_result_file,"/*!101100 SET system_versioning_insert_history=1 */;\n");
+      fprintf(md_result_file,"/*!101100 SET @old_system_versioning_insert_history=@@session.system_versioning_insert_history, @@session.system_versioning_insert_history=1 */;\n");
       check_io(md_result_file);
     }
     if (opt_lock)
@@ -4631,7 +4631,7 @@ static void dump_table(const char *table, const char *db, const uchar *hash_key,
     }
     if (versioned && !opt_xml && opt_dump_history)
     {
-      fprintf(md_result_file,"/*!101100 SET system_versioning_insert_history=1 */;\n");
+      fprintf(md_result_file,"/*!101100 SET system_versioning_insert_history=@old_system_versioning_insert_history */;\n");
       check_io(md_result_file);
     }
     mysql_free_result(res);

mysql-test/suite/versioning/r/data.result

@@ -93,10 +93,10 @@ CREATE TABLE `t1` (
   `x` int(11) DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci WITH SYSTEM VERSIONING;
 /*!40101 SET character_set_client = @saved_cs_client */;
-/*!101100 SET system_versioning_insert_history=1 */;
+/*!101100 SET @old_system_versioning_insert_history=@@session.system_versioning_insert_history, @@session.system_versioning_insert_history=1 */;
 INSERT INTO `t1` (`x`, row_start, row_end) VALUES (1,'2010-10-10 10:10:10.101010','2011-11-11 11:11:11.111111'),
 (2,'2010-10-10 10:10:10.101010','2038-01-19 03:14:07.999999');
-/*!101100 SET system_versioning_insert_history=1 */;
+/*!101100 SET system_versioning_insert_history=@old_system_versioning_insert_history */;
 /*!40101 SET @saved_cs_client     = @@character_set_client */;
 /*!40101 SET character_set_client = utf8 */;
 CREATE TABLE `t2` (
@@ -106,10 +106,10 @@ CREATE TABLE `t2` (
   PERIOD FOR SYSTEM_TIME (`row_start`, `row_end`)
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci WITH SYSTEM VERSIONING;
 /*!40101 SET character_set_client = @saved_cs_client */;
-/*!101100 SET system_versioning_insert_history=1 */;
+/*!101100 SET @old_system_versioning_insert_history=@@session.system_versioning_insert_history, @@session.system_versioning_insert_history=1 */;
 INSERT INTO `t2` (`x`, `row_start`, `row_end`) VALUES (1,'2010-10-10 10:10:10.101010','2011-11-11 11:11:11.111111'),
 (2,'2010-10-10 10:10:10.101010','2038-01-19 03:14:07.999999');
-/*!101100 SET system_versioning_insert_history=1 */;
+/*!101100 SET system_versioning_insert_history=@old_system_versioning_insert_history */;
 mysqldump: --dump-history can't be used with --as-of.
 mysqldump: --dump-history can't be used with --replace.
 mysqldump: --xml can't be used with --dump-history.