From 1e7b16082730a6f8d16e70c89450b964e6861716 Mon Sep 17 00:00:00 2001
From: Ti Chi Robot <ti-community-prow-bot@tidb.io>
Date: Wed, 24 Jan 2024 21:42:20 +0800
Subject: [PATCH] restore: correct new collation when
 "--check-requirements=false" (#49579) (#49957)

close pingcap/tidb#49466
---
 br/pkg/restore/client.go      | 48 +++++++++++++++++------------------
 br/pkg/restore/client_test.go | 10 ++++++--
 br/pkg/task/restore.go        |  2 +-
 3 files changed, 33 insertions(+), 27 deletions(-)

diff --git a/br/pkg/restore/client.go b/br/pkg/restore/client.go
index c8f2db94a19f6..58bf97b031df0 100644
--- a/br/pkg/restore/client.go
+++ b/br/pkg/restore/client.go
@@ -2880,43 +2880,43 @@ func CheckNewCollationEnable(
 	g glue.Glue,
 	storage kv.Storage,
 	CheckRequirements bool,
-) error {
-	if backupNewCollationEnable == "" {
-		if CheckRequirements {
-			return errors.Annotatef(berrors.ErrUnknown,
-				"the config 'new_collations_enabled_on_first_bootstrap' not found in backupmeta. "+
-					"you can use \"show config WHERE name='new_collations_enabled_on_first_bootstrap';\" to manually check the config. "+
-					"if you ensure the config 'new_collations_enabled_on_first_bootstrap' in backup cluster is as same as restore cluster, "+
-					"use --check-requirements=false to skip this check")
-		}
-		log.Warn("the config 'new_collations_enabled_on_first_bootstrap' is not in backupmeta")
-		return nil
-	}
-
+) (bool, error) {
 	se, err := g.CreateSession(storage)
 	if err != nil {
-		return errors.Trace(err)
+		return false, errors.Trace(err)
 	}
 
 	newCollationEnable, err := se.GetGlobalVariable(utils.GetTidbNewCollationEnabled())
 	if err != nil {
-		return errors.Trace(err)
-	}
-
-	if !strings.EqualFold(backupNewCollationEnable, newCollationEnable) {
-		return errors.Annotatef(berrors.ErrUnknown,
-			"the config 'new_collations_enabled_on_first_bootstrap' not match, upstream:%v, downstream: %v",
-			backupNewCollationEnable, newCollationEnable)
+		return false, errors.Trace(err)
 	}
-
 	// collate.newCollationEnabled is set to 1 when the collate package is initialized,
 	// so we need to modify this value according to the config of the cluster
 	// before using the collate package.
 	enabled := newCollationEnable == "True"
 	// modify collate.newCollationEnabled according to the config of the cluster
 	collate.SetNewCollationEnabledForTest(enabled)
-	log.Info("set new_collation_enabled", zap.Bool("new_collation_enabled", enabled))
-	return nil
+	log.Info("set new_collations_enabled_on_first_bootstrap", zap.Bool("new_collation_enabled", enabled))
+
+	if backupNewCollationEnable == "" {
+		if CheckRequirements {
+			return enabled, errors.Annotatef(berrors.ErrUnknown,
+				"the value 'new_collations_enabled_on_first_bootstrap' not found in backupmeta. "+
+					"you can use \"SELECT VARIABLE_VALUE FROM mysql.tidb WHERE VARIABLE_NAME='new_collations_enabled_on_first_bootstrap';\" to manually check the config. "+
+					"if you ensure the value 'new_collations_enabled_on_first_bootstrap' in backup cluster is as same as restore cluster, use --check-requirements=false to skip this check",
+			)
+		}
+		log.Warn("the config 'new_collations_enabled_on_first_bootstrap' is not in backupmeta")
+		return enabled, nil
+	}
+
+	if !strings.EqualFold(backupNewCollationEnable, newCollationEnable) {
+		return enabled, errors.Annotatef(berrors.ErrUnknown,
+			"the config 'new_collations_enabled_on_first_bootstrap' not match, upstream:%v, downstream: %v",
+			backupNewCollationEnable, newCollationEnable)
+	}
+
+	return enabled, nil
 }
 
 type waitTiFlashBackoffer struct {
diff --git a/br/pkg/restore/client_test.go b/br/pkg/restore/client_test.go
index d917993391e46..20caa8ed5fe2f 100644
--- a/br/pkg/restore/client_test.go
+++ b/br/pkg/restore/client_test.go
@@ -1839,19 +1839,25 @@ func TestCheckNewCollationEnable(t *testing.T) {
 			CheckRequirements:           true,
 			isErr:                       true,
 		},
+		{
+			backupMeta:                  &backuppb.BackupMeta{NewCollationsEnabled: ""},
+			newCollationEnableInCluster: "False",
+			CheckRequirements:           false,
+			isErr:                       false,
+		},
 	}
 
 	for i, ca := range caseList {
 		g := &gluetidb.MockGlue{
 			GlobalVars: map[string]string{"new_collation_enabled": ca.newCollationEnableInCluster},
 		}
-		err := restore.CheckNewCollationEnable(ca.backupMeta.GetNewCollationsEnabled(), g, nil, ca.CheckRequirements)
-
+		enabled, err := restore.CheckNewCollationEnable(ca.backupMeta.GetNewCollationsEnabled(), g, nil, ca.CheckRequirements)
 		t.Logf("[%d] Got Error: %v\n", i, err)
 		if ca.isErr {
 			require.Error(t, err)
 		} else {
 			require.NoError(t, err)
 		}
+		require.Equal(t, ca.newCollationEnableInCluster == "True", enabled)
 	}
 }
diff --git a/br/pkg/task/restore.go b/br/pkg/task/restore.go
index a6dab1c9d2729..fa9f60889852e 100644
--- a/br/pkg/task/restore.go
+++ b/br/pkg/task/restore.go
@@ -584,7 +584,7 @@ func runRestore(c context.Context, g glue.Glue, cmdName string, cfg *RestoreConf
 			return errors.Trace(versionErr)
 		}
 	}
-	if err = restore.CheckNewCollationEnable(backupMeta.GetNewCollationsEnabled(), g, mgr.GetStorage(), cfg.CheckRequirements); err != nil {
+	if _, err = restore.CheckNewCollationEnable(backupMeta.GetNewCollationsEnabled(), g, mgr.GetStorage(), cfg.CheckRequirements); err != nil {
 		return errors.Trace(err)
 	}