From 79a1980cae334fbecbdeebe986f5db17bab221b7 Mon Sep 17 00:00:00 2001
From: Erik Cederstrand <erik@cederstrand.dk>
Date: Sat, 22 May 2021 14:10:43 +0200
Subject: [PATCH] Pull in upstream commit 2dc1deee

Fix for Clubhouse story 58700
---
 exchangelib/properties.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/exchangelib/properties.py b/exchangelib/properties.py
index 69a55f7..a4abffc 100644
--- a/exchangelib/properties.py
+++ b/exchangelib/properties.py
@@ -647,15 +647,17 @@ class FreeBusyView(EWSElement):
     @classmethod
     def from_xml(cls, elem, account):
         kwargs = {}
+        working_hours_elem = elem.find('{%s}WorkingHours' % TNS)
         for f in cls.FIELDS:
             if f.name == 'working_hours':
-                kwargs[f.name] = f.from_xml(elem=elem.find('{%s}WorkingHours' % TNS), account=account)
+                if working_hours_elem is None:
+                    continue
+                kwargs[f.name] = f.from_xml(elem=working_hours_elem, account=account)
                 continue
             kwargs[f.name] = f.from_xml(elem=elem, account=account)
         elem.clear()
         return cls(**kwargs)
 
-
 class RoomList(Mailbox):
     # MSDN: https://msdn.microsoft.com/en-us/library/office/dd899514(v=exchg.150).aspx
     ELEMENT_NAME = 'RoomList'