From e2ff51fb8c76957c4deb72381a3943735d11fce0 Mon Sep 17 00:00:00 2001
From: Zak Zhao <57036248+joccau@users.noreply.github.com>
Date: Thu, 9 Feb 2023 23:53:59 +0800
Subject: [PATCH] This is an automated cherry-pick of #41000

Signed-off-by: ti-chi-bot <ti-community-prow-bot@tidb.io>
---
 br/pkg/backup/client.go         |  2 +-
 br/pkg/utils/schema.go          |  6 ++++++
 br/tests/br_backup_empty/run.sh | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/br/pkg/backup/client.go b/br/pkg/backup/client.go
index ad26ba4b2d5c3..da5f670813145 100644
--- a/br/pkg/backup/client.go
+++ b/br/pkg/backup/client.go
@@ -283,7 +283,7 @@ func BuildBackupRangeAndSchema(
 
 	for _, dbInfo := range dbs {
 		// skip system databases
-		if !tableFilter.MatchSchema(dbInfo.Name.O) || util.IsMemDB(dbInfo.Name.L) {
+		if !tableFilter.MatchSchema(dbInfo.Name.O) || util.IsMemDB(dbInfo.Name.L) || utils.IsTemplateSysDB(dbInfo.Name) {
 			continue
 		}
 
diff --git a/br/pkg/utils/schema.go b/br/pkg/utils/schema.go
index f6374576f43ed..797df838fdffc 100644
--- a/br/pkg/utils/schema.go
+++ b/br/pkg/utils/schema.go
@@ -16,6 +16,7 @@ import (
 
 // temporaryDBNamePrefix is the prefix name of system db, e.g. mysql system db will be rename to __TiDB_BR_Temporary_mysql
 const temporaryDBNamePrefix = "__TiDB_BR_Temporary_"
+const temporarySysDB = temporaryDBNamePrefix + "mysql"
 
 // NeedAutoID checks whether the table needs backing up with an autoid.
 func NeedAutoID(tblInfo *model.TableInfo) bool {
@@ -96,6 +97,11 @@ func EncloseDBAndTable(database, table string) string {
 	return fmt.Sprintf("%s.%s", EncloseName(database), EncloseName(table))
 }
 
+// IsTemplateSysDB checks wheterh the dbname is temporary system database(__TiDB_BR_Temporary_mysql).
+func IsTemplateSysDB(dbname model.CIStr) bool {
+	return dbname.O == temporarySysDB
+}
+
 // IsSysDB tests whether the database is system DB.
 // Currently, the only system DB is mysql.
 func IsSysDB(dbLowerName string) bool {
diff --git a/br/tests/br_backup_empty/run.sh b/br/tests/br_backup_empty/run.sh
index 943acb9506c81..4db197f8fd572 100644
--- a/br/tests/br_backup_empty/run.sh
+++ b/br/tests/br_backup_empty/run.sh
@@ -41,14 +41,47 @@ run_sql "CREATE TABLE $DB.usertable1 ( \
   PRIMARY KEY (YCSB_KEY) \
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;"
 
+<<<<<<< HEAD
 echo "backup start..."
 run_br --pd $PD_ADDR backup full -s "local://$TEST_DIR/empty_table"
 
 run_sql "DROP DATABASE $DB;"
 echo "restore start..."
+=======
+# backup empty table
+echo "backup empty table start..."
+run_br --pd $PD_ADDR backup full -s "local://$TEST_DIR/empty_table"
+
+while [ $i -le $DB_COUNT ]; do
+    run_sql "DROP DATABASE $DB$i;"
+    i=$(($i+1))
+done
+
+# restore empty table.
+echo "restore empty table start..."
+>>>>>>> 7f88e73af6 (br: skip template system table __TiDB_BR_Temporary_mysql when backup (#41000))
 run_br --pd $PD_ADDR restore full -s "local://$TEST_DIR/empty_table"
 
 # insert one row to make sure table is restored.
 run_sql "INSERT INTO $DB.usertable1 VALUES (\"a\", \"b\");"
 
+<<<<<<< HEAD
 run_sql "DROP DATABASE $DB"
+=======
+while [ $i -le $DB_COUNT ]; do
+    run_sql "DROP DATABASE $DB$i;"
+    i=$(($i+1))
+done
+
+
+# backup, skip temporary system database(__TiDB_BR_Temporary_mysql) when backup
+run_sql "CREATE DATABASE __TiDB_BR_Temporary_mysql";
+run_sql "CREATE TABLE __TiDB_BR_Temporary_mysql.tables_priv(id int);";
+echo "backup and skip __TiDB_BR_Temporary_mysql start..."
+run_br --pd $PD_ADDR backup full -s "local://$TEST_DIR/skip_temporary_mysql"
+
+# restore successfully without panic.
+run_sql "DROP DATABASE __TiDB_BR_Temporary_mysql";
+echo "restore the data start..."
+run_br restore full -s "local://$TEST_DIR/skip_temporary_mysql" --pd $PD_ADDR --ratelimit 1024
+>>>>>>> 7f88e73af6 (br: skip template system table __TiDB_BR_Temporary_mysql when backup (#41000))