fix hangup when error in multi resultsets (#1462)

Fix #1361

Co-authored-by: Inada Naoki <songofacandy@gmail.com>

AUTHORS

@@ -13,6 +13,7 @@
 
 Aaron Hopkins <go-sql-driver at die.net>
 Achille Roussel <achille.roussel at gmail.com>
+Aidan <aidan.liu at pingcap.com>
 Alex Snast <alexsn at fb.com>
 Alexey Palazhchenko <alexey.palazhchenko at gmail.com>
 Andrew Reid <andrew.reid at tixtrack.com>

driver_test.go

@@ -3430,3 +3430,44 @@ func TestConnectionAttributes(t *testing.T) {
 	}
 	rows.Close()
 }
+
+func TestErrorInMultiResult(t *testing.T) {
+	// https://github.com/go-sql-driver/mysql/issues/1361
+	var db *sql.DB
+	if _, err := ParseDSN(dsn); err != errInvalidDSNUnsafeCollation {
+		db, err = sql.Open("mysql", dsn)
+		if err != nil {
+			t.Fatalf("error connecting: %s", err.Error())
+		}
+		defer db.Close()
+	}
+
+	dbt := &DBTest{t, db}
+	query := `
+CREATE PROCEDURE test_proc1()
+BEGIN
+	SELECT 1,2;
+	SELECT 3,4;
+	SIGNAL SQLSTATE '10000' SET MESSAGE_TEXT = "some error",  MYSQL_ERRNO = 10000;
+END;
+`
+	runCallCommand(dbt, query, "test_proc1")
+}
+
+func runCallCommand(dbt *DBTest, query, name string) {
+	dbt.mustExec(fmt.Sprintf("DROP PROCEDURE IF EXISTS %s", name))
+	dbt.mustExec(query)
+	defer dbt.mustExec("DROP PROCEDURE " + name)
+	rows, err := dbt.db.Query(fmt.Sprintf("CALL %s", name))
+	if err != nil {
+		return
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+	}
+	for rows.NextResultSet() {
+		for rows.Next() {
+		}
+	}
+}

rows.go

@@ -163,7 +163,13 @@ func (rows *mysqlRows) nextResultSet() (int, error) {
 	rows.rs = resultSet{}
 	// rows.mc.affectedRows and rows.mc.insertIds accumulate on each call to
 	// nextResultSet.
-	return rows.mc.resultUnchanged().readResultSetHeaderPacket()
+	resLen, err := rows.mc.resultUnchanged().readResultSetHeaderPacket()
+	if err != nil {
+		// Clean up about multi-results flag
+		rows.rs.done = true
+		rows.mc.status = rows.mc.status & (^statusMoreResultsExists)
+	}
+	return resLen, err
 }
 
 func (rows *mysqlRows) nextNotEmptyResultSet() (int, error) {