From d6e74cf9cb78de1e93582fc6e64761642093fa7b Mon Sep 17 00:00:00 2001
From: Francis Lachapelle <flachapelle@inverse.ca>
Date: Wed, 22 Nov 2017 09:30:19 -0500
Subject: [PATCH] Fix compilation warning

---
 SoObjects/Mailer/SOGoMailAccount.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/SoObjects/Mailer/SOGoMailAccount.m b/SoObjects/Mailer/SOGoMailAccount.m
index 0917c35b0..9dfd70d8a 100644
--- a/SoObjects/Mailer/SOGoMailAccount.m
+++ b/SoObjects/Mailer/SOGoMailAccount.m
@@ -797,7 +797,7 @@ static NSString *inboxFolderName = @"INBOX";
       else
         guid = [[[result objectForKey: @"status"] objectForKey: currentFolder] objectForKey: @"x-guid"];
       
-      if (!guid || [guid isNull])
+      if (!guid || ![guid isNotNull])
         {
           // Don't generate a GUID for "Other users" and "Shared" namespace folders - user foldername instead
           if ((otherUsersFolderName && [currentFolder isEqualToString: otherUsersFolderName]) ||