fix: timeout on query should return context.DeadlineExceeded (#4060)

core/stores/sqlx/sqlconn.go

@@ -296,7 +296,7 @@ func (db *commonSqlConn) queryRows(ctx context.Context, scanner func(*sql.Rows)
 
 		return query(ctx, conn, func(rows *sql.Rows) error {
 			e := scanner(rows)
-			if e != nil {
+			if e != nil && !errors.Is(e, context.DeadlineExceeded) {
 				scanFailed = true
 			}
 			return e

core/stores/sqlx/stmt_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"database/sql"
 	"errors"
+	"strconv"
 	"testing"
 	"time"
 
@@ -290,6 +291,24 @@ func TestStmtBreaker(t *testing.T) {
 	})
 }
 
+func TestQueryScanTimeout(t *testing.T) {
+	dbtest.RunTest(t, func(db *sql.DB, mock sqlmock.Sqlmock) {
+		ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond)
+		defer cancel()
+		row := sqlmock.NewRows([]string{"foo"})
+		for i := 0; i < 10000; i++ {
+			row = row.AddRow("bar" + strconv.Itoa(i))
+		}
+		var val []struct {
+			Foo int
+			Bar string
+		}
+		conn := NewSqlConnFromDB(db)
+		err := conn.QueryRowsCtx(ctx, &val, "any")
+		assert.ErrorIs(t, err, context.DeadlineExceeded)
+	})
+}
+
 type mockedSessionConn struct {
 	lastInsertId int64
 	rowsAffected int64