From 069430355cec1a869c2f09949d076ab8e57fcb37 Mon Sep 17 00:00:00 2001
From: stdex <sergey@rostunov.com>
Date: Sun, 12 Jul 2020 02:51:05 +0300
Subject: [PATCH] Performance improvement Fix concat string

---
 Spreadsheet/Excel/Writer/BIFFwriter.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Spreadsheet/Excel/Writer/BIFFwriter.php b/Spreadsheet/Excel/Writer/BIFFwriter.php
index cb08407..9d59894 100644
--- a/Spreadsheet/Excel/Writer/BIFFwriter.php
+++ b/Spreadsheet/Excel/Writer/BIFFwriter.php
@@ -163,7 +163,7 @@ class Spreadsheet_Excel_Writer_BIFFwriter extends PEAR
         if (strlen($data) > $this->_limit) {
             $data = $this->_addContinue($data);
         }
-        $this->_data      = $this->_data.$data;
+        $this->_data .= $data;
         $this->_datasize += strlen($data);
     }