ZP-968 Execute check on state usage only on ZCP versions before 7.2.3.

Nothing changes for systems without ZCP/KC as the check is executed as
before.

Released under the Affero GNU General Public License (AGPL) version 3.

src/lib/core/synccollections.php

@@ -679,12 +679,15 @@ class SyncCollections implements Iterator {
             return false;
         }
 
-        // prevent ZP-623 by checking if the states have been used before, if so force a sync on this folder
+        // Prevent ZP-623 by checking if the states have been used before, if so force a sync on this folder.
+        // ZCP/KC 7.2.3 and newer support SYNC_STATE_READONLY so this behaviour is not required (see ZP-968).
+        if (!Utils::CheckMapiExtVersion('7.2.3')) {
             if (ZPush::GetDeviceManager()->CheckHearbeatStateIntegrity($spa->GetFolderId(), $spa->GetUuid(), $spa->GetUuidCounter())) {
                 ZLog::Write(LOGLEVEL_DEBUG, "SyncCollections->CountChange(): Cannot verify changes for state as it was already used. Forcing sync of folder.");
                 $this->changes[$folderid] = 1;
                 return true;
             }
+        }
 
         $backendFolderId = ZPush::GetDeviceManager()->GetBackendIdForFolderId($folderid);
         // switch user store if this is a additional folder (additional true -> do not debug)