From fbd2eb8294f6b753995b95e4e8e59a5520acd477 Mon Sep 17 00:00:00 2001
From: Francis Lachapelle <flachapelle@inverse.ca>
Date: Thu, 24 Mar 2022 15:28:06 -0400
Subject: [PATCH] fix(calendar): rely on organizer's event state before
 updating attendee

When an attendee is adding a new event for which the organizer is local
but doesn't have the event anymore, return a 412 error code.

Fixes #5496
---
 .../Appointments/SOGoAppointmentObject.m      | 25 +++++++++++++++----
 SoObjects/SOGo/SOGoParentFolder.m             |  2 +-
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/SoObjects/Appointments/SOGoAppointmentObject.m b/SoObjects/Appointments/SOGoAppointmentObject.m
index c2ef31443d..8d10bc7be9 100644
--- a/SoObjects/Appointments/SOGoAppointmentObject.m
+++ b/SoObjects/Appointments/SOGoAppointmentObject.m
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2007-2020 Inverse inc.
+  Copyright (C) 2007-2022 Inverse inc.
 
   This file is part of SOGo
 
@@ -151,7 +151,8 @@ - (SOGoAppointmentObject *) _lookupEvent: (NSString *) eventUID
           if (possibleName)
             {
               object = [folder lookupName: possibleName
-                                inContext: context acquire: NO];
+                                inContext: context
+                                  acquire: NO];
               if ([object isKindOfClass: [NSException class]] || [object isNew])
                 object = nil;
             }
@@ -163,10 +164,9 @@ - (SOGoAppointmentObject *) _lookupEvent: (NSString *) eventUID
   if (!object)
     {
       // Create the event in the user's personal calendar.
-      folder = [[SOGoUser userWithLogin: uid]
-                 personalCalendarFolderInContext: context];
+      folder = [[SOGoUser userWithLogin: uid] personalCalendarFolderInContext: context];
       object = [SOGoAppointmentObject objectWithName: nameInContainer
-				                                 inContainer: folder];
+                                         inContainer: folder];
       [object setIsNew: YES];
     }
 
@@ -2528,6 +2528,7 @@ - (id) PUTAction: (WOContext *) _ctx
           iCalEvent *currentMasterEvent;
           NSArray *folders;
           NSEnumerator *e;
+          NSString *organizerUID;
           SOGoAppointmentFolder *folder;
           SOGoAppointmentObject *object;
 
@@ -2555,6 +2556,20 @@ - (id) PUTAction: (WOContext *) _ctx
                     }
                 }
             }
+
+          // Verify if the event is still present in the organizer calendar
+          organizerUID = [[masterEvent organizer] uidInContext: context];
+          if (organizerUID)
+            {
+              object = [self _lookupEvent: [masterEvent uid]
+                                   forUID: organizerUID];
+              if ([object isNew])
+                {
+                  // The event has vanished
+                  return [NSException exceptionWithDAVStatus: 412
+                                                      reason: @"Precondition Failed"];
+                }
+            }
         }
     }
   else
diff --git a/SoObjects/SOGo/SOGoParentFolder.m b/SoObjects/SOGo/SOGoParentFolder.m
index a1324b34e3..22cad405ad 100644
--- a/SoObjects/SOGo/SOGoParentFolder.m
+++ b/SoObjects/SOGo/SOGoParentFolder.m
@@ -177,7 +177,7 @@ - (void) createSpecialFolder: (SOGoFolderType) folderType
       [folder setOCSPath: [NSString stringWithFormat: @"%@/%@", OCSPath, folderName]];
       
       if ([folder create])
-      [subFolders setObject: folder forKey: folderName];
+        [subFolders setObject: folder forKey: folderName];
     }
     else if (folderType == SOGoCollectedFolder)
     {