Merge pull request #401 in ZP/z-push from...

Merge pull request #401 in ZP/z-push from feature/ZP-968-retest-ics-exports-delete-for-all to develop

* commit '4994dd57':
  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.
  ZP-968 Revert "ZP-968 Partially undo changes of commit aeab7567. This prevents access to the volatile state to check if the state was already used."
  ZP-968 Use 0x80000 flag when setting up exporter in Ping.
  ZP-968 Partially undo changes of commit aeab7567. This prevents access to the volatile state to check if the state was already used.

src/backend/kopano/exporter.php

@@ -134,8 +134,10 @@ class ExportChangesICS implements IExportChanges{
             }
         }
 
-        if($this->flags & BACKEND_DISCARD_DATA)
+        if($this->flags & BACKEND_DISCARD_DATA) {
             $this->exporterflags |= SYNC_CATCHUP;
+            $this->exporterflags |= SYNC_STATE_READONLY;
+        }
 
         // Put the state information in a stream that can be used by ICS
         $stream = mapi_stream_create();
@@ -305,6 +307,11 @@ class ExportChangesICS implements IExportChanges{
      * @return array
      */
     public function Synchronize() {
+        if ($this->flags & BACKEND_DISCARD_DATA) {
+            ZLog::Write(LOGLEVEL_WARN, 'ExportChangesICS->Synchronize(): not supported in combination with the BACKEND_DISCARD_DATA flag.');
+            return false;
+        }
+
         if ($this->exporter) {
             return mapi_exportchanges_synchronize($this->exporter);
         }

src/backend/kopano/mapi/mapidefs.php

@@ -596,6 +596,7 @@ define('SYNC_PROGRESS_MODE'                      ,0x8000);        // AirMapi pro
 define('SYNC_FXRECOVERMODE'                      ,0x10000);
 define('SYNC_DEFER_CONFIG'                       ,0x20000);
 define('SYNC_FORCE_UNICODE'                      ,0x40000);       // Forces server to return Unicode properties
+define('SYNC_STATE_READONLY'                     ,0x80000);       // Server will not update the states in the DB, setting up exporter with this flag states are read only
 
 define('EMS_AB_ADDRESS_LOOKUP'                   ,0x00000001);    // Flag for resolvename to resolve only exact matches
 

src/lib/core/synccollections.php

@@ -665,12 +665,15 @@ 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)