From 370da7d0a529a98f0a8c46db08ad1b06f5950306 Mon Sep 17 00:00:00 2001
From: ti-srebot <66930949+ti-srebot@users.noreply.github.com>
Date: Mon, 10 Oct 2022 14:17:49 +0800
Subject: [PATCH] executor: grant privilege to table now check table existence
 use case insensitive (#36778) (#36798)

close pingcap/tidb#34610
---
 executor/grant.go      |  5 +++--
 executor/grant_test.go | 26 +++++++++++++++++++++++---
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/executor/grant.go b/executor/grant.go
index 387ced7e69f40..2aabd3c4aca77 100644
--- a/executor/grant.go
+++ b/executor/grant.go
@@ -105,8 +105,9 @@ func (e *GrantExec) Next(ctx context.Context, req *chunk.Chunk) error {
 				return err
 			}
 		}
-		// Note the table name compare is case sensitive here.
-		if tbl != nil && tbl.Meta().Name.String() != e.Level.TableName {
+		// Note the table name compare is not case sensitive here.
+		// In TiDB, system variable lower_case_table_names = 2 which means name comparisons are not case-sensitive.
+		if tbl != nil && tbl.Meta().Name.L != strings.ToLower(e.Level.TableName) {
 			return infoschema.ErrTableNotExists.GenWithStackByArgs(dbName, e.Level.TableName)
 		}
 		if len(e.Level.DBName) > 0 {
diff --git a/executor/grant_test.go b/executor/grant_test.go
index 05d64b0d7b698..0519c778fe1bd 100644
--- a/executor/grant_test.go
+++ b/executor/grant_test.go
@@ -449,9 +449,9 @@ func TestGrantOnNonExistTable(t *testing.T) {
 	require.True(t, terror.ErrorEqual(err, infoschema.ErrTableNotExists))
 
 	tk.MustExec("create table if not exists xx (id int)")
-	// Case sensitive
-	_, err = tk.Exec("grant Select,Insert on XX to 'genius'")
-	require.True(t, terror.ErrorEqual(err, infoschema.ErrTableNotExists))
+	// Case insensitive, differ from MySQL default behaviour.
+	// In TiDB, system variable lower_case_table_names = 2, which means compare table name using lower case.
+	tk.MustExec("grant Select,Insert on XX to 'genius'")
 
 	_, err = tk.Exec("grant Select,Insert on xx to 'genius'")
 	require.NoError(t, err)
@@ -606,3 +606,23 @@ func TestNonExistTableIllegalGrant(t *testing.T) {
 	// Column level, not existing table, illegal privilege
 	tk.MustGetErrCode("grant create temporary tables (NotExistsCol) on NotExistsD29302.NotExistsT29302 to u29302;", mysql.ErrWrongUsage)
 }
+
+func TestIssue34610(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("DROP DATABASE IF EXISTS d1;")
+	tk.MustExec("CREATE DATABASE d1;")
+	tk.MustExec("USE d1;")
+	tk.MustExec("CREATE USER user_1@localhost;")
+	defer func() {
+		tk.MustExec("DROP DATABASE d1;")
+		tk.MustExec("DROP USER user_1@localhost;")
+	}()
+
+	tk.MustExec("CREATE TABLE T1(f1 INT);")
+	tk.MustGetErrCode("CREATE TABLE t1(f1 INT);", mysql.ErrTableExists)
+	tk.MustExec("GRANT SELECT ON T1 to user_1@localhost;")
+	tk.MustExec("GRANT SELECT ON t1 to user_1@localhost;")
+}