*: close transaction for all auto-committed SQLs

Signed-off-by: Shuaipeng Yu <jackysp@gmail.com>

executor/simple_test.go

@@ -57,6 +57,16 @@ func (s *testSuite3) TestDo(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	tk.MustExec("do 1, @a:=1")
 	tk.MustQuery("select @a").Check(testkit.Rows("1"))
+
+	tk.MustExec("use test")
+	tk.MustExec("create table t (i int)")
+	tk.MustExec("insert into t values (1)")
+	tk2 := testkit.NewTestKit(c, s.store)
+	tk2.MustExec("use test")
+	tk.MustQuery("select * from t").Check(testkit.Rows("1"))
+	tk.MustExec("do @a := (select * from t where i = 1)")
+	tk2.MustExec("insert into t values (2)")
+	tk.MustQuery("select * from t").Check(testkit.Rows("1", "2"))
 }
 
 func (s *testSuite3) TestSetRoleAllCorner(c *C) {

session/tidb.go

@@ -325,7 +325,6 @@ func runStmt(ctx context.Context, sctx sessionctx.Context, s sqlexec.Statement)
 		} else {
 			logutil.BgLogger().Error("get txn failed", zap.Error(err1))
 		}
-		err = finishStmt(ctx, se, err, s)
 	}
 
 	if rs != nil {
@@ -336,6 +335,7 @@ func runStmt(ctx context.Context, sctx sessionctx.Context, s sqlexec.Statement)
 		}, err
 	}
 
+	err = finishStmt(ctx, se, err, s)
 	if se.hasQuerySpecial() {
 		// The special query will be handled later in handleQuerySpecial,
 		// then should call the ExecStmt.FinishExecuteStmt to finish this statement.