From 544c67e8b2dacb910ce9c77d9bef10875de30991 Mon Sep 17 00:00:00 2001
From: Gasol Wu <gasolwu@kkbox.com>
Date: Fri, 14 Dec 2018 14:37:11 +0800
Subject: [PATCH] Ensure a string return by curlExec

Fix error like

    TypeError: Return value of Sabre\HTTP\Client::curlExec() must be of
    the type string, boolean returned
---
 lib/Client.php | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/Client.php b/lib/Client.php
index 88a2599..c152d91 100644
--- a/lib/Client.php
+++ b/lib/Client.php
@@ -588,7 +588,12 @@ protected function curlExec($curlHandle): string
     {
         $this->headerLinesMap[(int) $curlHandle] = [];
 
-        return curl_exec($curlHandle);
+        $result = curl_exec($curlHandle);
+        if (false === $result) {
+            $result = '';
+        }
+
+        return $result;
     }
 
     /**